From the SDML archives- Engine development engineer David Zelkowski

Mr. Zelkowski was a regular poster to the Shelby Dodge mailing list from 1997-1999. After culling through thousands of posts by and related to him here is a summary of the more interesting topics... Dave was involved with or in charge of numerous projects (S-60 package, Stratus super-touring race cars, Indy Lebaron pace car, etc..) within Chrysler and I'm sure only a few of them are listed here... Dave is one of the unsung heroes of the auto industry who's good work is rarely seen...

Dave carving up a corner at SDAC-2 with his Iroc 16V Daytona 

1)  Super 60 package related.

2)   Cylinder heads, intake manifolds, long rod engines & headgaskets.

3)   Fuel injectors, ECU's & Ignition system related.

4)   Manual transmission data.

5)   DOHC 2.2 Turbo.

6)   Magic in a can (dyno results)

7)   Production nit's, picks' fact's & figures.

8)   MP computers & parts.

9)   Dave's math class.

10)  Stuff on rear disk brakes and braking hardware.

11)  Aftermarket- extrude hone, rods, electromotive & piston coatings.

12)  Historical tidbits.

Super 60 package related.

On Super 60 camshaft...

David Zelkowski wrote:  Just a comment about cams. During development of Super 60, I had a number of different recommendations on camshafts that various people tried that made "their car" quicker. Seven different cams were tried. Only one made more power than the stock cam. That is the one that Mike Taylor came up with which is now the Super 60 cam. I'm sure it wasn't the optimal design but it was the ONLY one that made more than the stock cam. This wasn't "seat of the pants" but true dyno power working with several Chrysler engineers on their own time.

Also my Super 60 equipped engine idled at 12" Hg.

On custom roller followers for S-60 cam...

Possibly. It would also require a new Super 60 cam. The geometry of the roller and slider cams are totally different and roller followers cannot be run on a slider cam.

More roller cam vs. S-60...

"Why do the Super-60 and other high performance cams use slider cam followers instead of roller cam followers? I thought rollers were better than sliders because rolling friction is significantly less than sliding friction. Have I totally missed the mark on this?"

The roller cams were introduced to reduce idle fuel consumption by reducing friction. The roller cam profiles cannot be as radical as the slider because of the small radius of the roller. The radius of the slider is much larger. This is similar to NASCAR using "mushroom" tappets in their engines. The slider is much more stable at high engine speeds.

On S-60 cam installation...

"What's the best break-in procedure and oil to use to break in a Super 60 cam and springs, lifters, and followers? I've heard these cams sometimes have premature wear so I want to make sure I don't do anything to make it worse."

 I always use a moly based lubricant liberally applied to the cam lobes. I also like to use a lighter valve spring for break-in and then put the 540's in afterwards. Do not let the engine run below 2000 rpm for the first 10 minutes. I've always used a high quality mineral oil because it needs to be changed after break-in. I usually head for the freeway and run a half an hour or so. One other thing comes to mind. On the Team Shelby GTU car we had a problem with cams wiping and after some investigation we found that the squirt holes in some cam caps did not squirt on the lobes. They were squirting between the lobes. We redrilled them so they would squirt directly on the lobes. This cured the problem.

More Super-60 (computer)

"From what I understand the Super 60 computer uses an SBEC from Mexico. I also believe that none of the drivers for the cruise control are on the board either. Main reason you can't get the cruise to work with the s-60 computer. If you have an extra SBEC laying around, open it up and look inside and how many heat sink/drivers it has. Then compare it to the S-60. I believe that there will be less, at least this is what I am lead to believe. I never really took a S-60 computer apart so I couldn't tell you one way or the other."

The Super 60 SMEC is just a production turbo SMEC with a different calibration. The cruise control circuits don't work because the original software was derived from the 1988 Team Shelby GTU car. Those three connections were connected to a binary switch which allowed the boost to be cockpit adjustable on the fly. That is also the way my old 'Omni From Hell' was. That feature was not incorporated into the Super 60 electronics though.

Cruise control & S-60 electronics...

 No, I don't believe it will. The cruise control circuits were used to control boost in the original S60 software. It wasn't implemented that way in the final product but the cruise control code was never there, since the software is a derivative of the IMSA GTU Daytona.

On altitude affecting the S-60 electronics...

This is NOT true in Super 60. Part of the development was done with Doug Shepherd's rally car which he had raced at Pike's Peak. To keep the power level up the calibration work off of absolute pressure instead of gauge pressure. The engine will make nearly identical power at altitude with Super 60! Of course it does have to spin the turbo harder and the lag is worse but once the boost comes up it flies!  

More Super-60 (map sensor)

"I just received my S-60 computer and am trying to install the 3 bar map sensor. The connector is keyed differently. Do I just "make" it work, or is there a trick??"

On my 3 bar map sensor I grabbed the keyed insert in the map sensor with some needle nose pliers and yanked it out. I then filed the keys off and reinstalled it into the map sensor.

More Super-60 (MP Harness)

"There never was an official T2 wiring harness for an L body produced car in the United States. The S 60 wiring harness is a direct replacement for L bodies which would lead me to believe they are merely left over harnesses from the T2 Mexican L-body. You could go to a junk yard and get a 1988 T2 harness from say a Lancer Shelby a Daytona Shelby Z but make sure it's from a true T2 car NOT a T1. The T1 cars lack the charge temp sensor and you'll have to wire one in. Not difficult or a big deal but it is a pain. So, there are harnesses that will work but the S 60 harness is the only one designed for L body duty- Jason Flood"

This isn't true. The S60 harness was custom built on my "Omni from Hell" and given to a wiring harness manufacturer to custom produce. Their first attempt was tried on my car and several changes were made to make it fit correctly. It wasn't a "leftover" anything.

On the S-60 intercooler...

"What exactly is the "Indy" intercooler package. I was looking in the FM catalog and saw that its only $250. Is it mounted in a different place on the car? Is it a stock intercooler with the paint removed? :)  Ed Peters said that the Indy intercooler is a stock unit with 19 fins removed internally to reduce the pressure drop across the unit to promote flow. However, less fins means reduced cooling efficiency. So the whole thing is a trade-off. I can't see the point in spending money on a trade off that more or less puts you back where you started. Kind of like paying 10% less money for a part that expires 10% sooner. What's the point? Has anyone noticed an improvement over stock on a slightly modified T2? Find an intercooler that flows better, AND is more efficient, and you've got a reason to spend money. You'll see a significant improvement, not a trade off. Gus. "

ALL intercoolers have tradeoffs. The stock intercooler is efficient at low vehicle speeds but was restrictive. One completely packed with fins would be more efficient for heat transfer but with more restrictive air flow. A larger intercooler with a lot of fins would have more volume and increase lag. You have to understand that to make it easy for everyone to make more power we couldn't make a big intercooler and say "Remote mount the oil filter. Move fan to front of radiator. Mount radiator in front of grill." Etc, etc. We did it. It makes 300hp.

Cylinder heads, intake manifolds, long rod engines & headgaskets.

On differences between cylinder head machining..

"What are the differences between the Turbo and non-turbo heads? I have one of each and they look  the same."

The fast burn heads are different for a turbo and non-turbo. The turbo has a "tapered shroud" and the NA has a "straight shroud" around the intake valve. The shroud is tapered at a 7degree angle away from the valve, the NA head has no taper. The head is usually stamped on the end "TS" or "SS" to identify the type of shroud.

On cylinder head re-torquing

The bolts always become a little loose after the engine is thermocycled. The aluminum head expands, further compressing the head gasket. When cooled off, the gasket has taken a set and the bolts have become loose. I retorque the four corner bolts to 85 lb-ft and the rest of the bolts to 90 lb-ft. This is ONLY with the 11mm head bolts ('86 and up). DO NOT retorque 10mm headbolts.

O-ringing a stock head gasket

"Anyone ever try o-ringing a stock head gasket? Doesn't look to be a whole lot of material on the gasket. I have to use a T3 gasket so other than going copper, I have no choice but to use a stock one."

All I've ever used was the stock head gasket. Just o-ring the block using 0.041 stainless wire and have the wire stick 0.007 above the deck. DaveZ. Dave and Charlene wrote: > > 

On checking valve tip height...

Valve tip height can be measured as follows with a depth micrometer. With a cam cap removed place the base of the mike on the flat of the cam tower. Measure the distance to the closest portion of the valve tip. It should measure between 1.320 to 1.330 inches.

Cross-drilling cylinder heads and blocks

The purpose of cross drilling is to reduce the temperature of the head gasket between the cylinder bores. If I recall correctly it was in the neighborhood of a 150F degree reduction. (Ed's note: 75C) This was a necessity on the Turbo II's to make the head gasket live at the elevated cylinder pressures. Originally the engines were to be double cross drilled, drilled from each side of the deck and intersected. This was dropped because of difficulties in performing this operation. All of the Team Shelby race engines and the ones I have built were double cross drilled.

On "long rod, tall deck" 2.5 engines...

I've been following this thread and I think it's a poor allocation of resources to concentrate on rod ratio. The amount that it contributes to output is miniscule, if it does contribute at all, compared to the gains to be had in the cylinder head/induction system. In the reference to the V8 gain of 8 HP, what was that as a percentage of total output? If it's less than 2% or so it's probably not even real. Most dyno's won't even repeat run-to-run within that range. It's also likely that the runs were not done on the same day. Therefore, a correction factor would have been applied and believe me they don't correct that closely. I've got three performance dyno cells running at CTC now and this is from experience. To be sure that a change is effective I do a minimum of three runs for a baseline, change the hardware make three runs, return to the original baseline hardware and make three more runs. Then the data has to make sense. There better be good correlation in output, BSFC and BMEP or I'll do it all over again. I know in the old Stratus Super Touring Engine we placed zero importance on rod ratio. We talked about it but we couldn't find anyone with good credentials to give any credence to the theory, like Geoff Goddard from Walkinshaw Racing. We ran different rod lengths over the course of the three years we worked on the engine from 136mm to 146mm but these changes were only to accommodate different piston designs. In fact JanSpeed Engineering of the UK, who ran the Nissan super tourers, suggested SHORTER rods. There maybe something to the idea of longer piston dwell time at TDC but it was felt that it would only be worth something if we spun the engine to 10,000 rpm and we were dictated by rules to run no higher than 8500rpm. Don't try revving your 2.5 to 8500rpm. The 2.5 turbo is definitely not a revver. Piston speeds are through the roof! Will placing all importance on having a perfect 1.8:1 rod ratio make all the difference? I doubt it. I am convinced from the Super Touring project that the intake side of the engine is where the power comes from. Of course that engine was normally aspirated and should be more sensitive to hardware choices than a turbo engine. On the Super Touring engine a 10mm change in intake length could change output by 30HP making no other changes!

Why was the 2 piece intake manifold discontinued?

One simple reason. Cost. It was much less expensive to produce the 1 piece intake. Output is equal if the engine is stock. Modified engines will do better with the two piece if the runners are matched at the parting line.

Why did Mopar go to "blow through" throttle bodies?

One main reason is if an intercooler hose failed with the upstream throttle body the engine would be un-throttled and the lawyers would have a field day.

Hmmm.. the missing cylinder head again...

Yeah Doug, that was Bob Green from the transmission lab. His engine didn't have the big valve head or turbo. Since then Bob's gone 13.50's with what we call a plus 2 minus 2 cylinder head. It's got a 2mm larger intake valve and a 2mm smaller exhaust valve. It was slated for production (don't remember when) but got pulled last minute. It made a considerable performance improvement.

Fuel injectors, ECU's & Ignition system related.

On fluctuating spark...

From: David Zelkowski-   I don't know if any body got the answer to Jeff's question on the fluctuating spark. It's caused by the excess clearance between the distributor drive blade and its corresponding slot in the oil pump shaft.

 Here's the Team Shelby fix. Take out the distributor and hold it upside down in your left hand (or right hand if you're left handed). Get a hammer and smack the drive blade several times to slightly mushroom the end. Check the fit back in the engine. When it's just right the distributor will go in with some light resistance. It's crude but it works!

On the damn thermostat mounted coil...

"And if memory serves me correctly, in the Car & Driver One Lap, the stock ignition coil (bolted on the head where the inlet for the radiator is) failed on the "Omni from Hell". At the very least, I would move the coil off the head to thermally isolate it. Those laminations probably work a lot better when their not superheated. I know from my R/C racing days that an electric motor won't be the same if you zap it with too much heat. That coil could be the same I believe."

Actually there was a lot of corrosion in some of the plug wire connections probably forcing the coil to put out higher voltages which led to its failure. The current Dodge Super Touring Stratus uses a stock ignition system and a stock engine controller and makes 300hp normally aspirated.

More about aftermarket ignition...

The ONLY thing they will do for you is lighten your wallet. If there is nothing wrong with the stock ignition components it won't help. If you have some old tired components then it could be a benefit. I've been through this aftermarket ignition thing before. I spent a week on the dyno with the Super Touring 2.0L testing five different systems whose manufacturer's claimed big results. I found zero. The down side to their systems were that the complexity was increased and they weighed more.

Fuel and programming... 

"Here's what's going on. When you go to WOT, the computer jumps to a different fuel curve that is super rich. When you back off the throttle just a little bit, the computer will hold out at full boost, but jump back to the part throttle curve which is a bit leaner, there by running quite a bit harder! Kind of a strange feeling isn't it? What's the recommended solution to this? I've noticed this on all of my Dodge turbo cars, and it's rather strange..."

Chris, It's there for a reason. Fuel at WOT is added to prevent excessively high exhaust temperature which will burn the tips off of your turbo blades, burn the exhaust valves, melt pistons. You may feel its odd behavior, but remove it and you'll be lightening your wallet when the repair bills show up for damaged engine components. 

More fuel and airflow related...

Dave replied to Jim question about injector balancing "No, this is not necessarily true. This would ONLY be true if the air flow to each cylinder is identical. Guess what? It's not. On the turbo race engines we often juggled injectors to make up for cylinder to cylinder fuel/air discrepancies.

 Question for Dave: How did you determine/measure fuel/air discrepancies between cylinders and at what point did you change injectors???  thanks, Dan 

The fuel/air is measured through a tube plumbed into each exhaust runner in the exhaust manifold. This is then run into an emission bench at the dyno cell checking one cylinder at a time. This takes about 45-60 seconds at each engine speed. The injectors were all flowed on a flow bench so we know which ones flow more and which ones flow less. They are then juggled in the engine as needed to try to optimize fuel/air. This is necessary in the old turbo engines because the injection is not sequential, it is bank fire. In the Super Touring 2.0L, the software we use allows individual cylinder fuel/air ratio control.

On checking EGT temps...

It'll come real close if measured just in front of the turbo. The exhaust port temps tend to be cooler than the collector temps. The combustion process is not complete at the port and the process continues in the exhaust. My dyno engines will typically read 150 degrees cooler at the port than at the collector.

Manual transmission data

On transmission gear material...

The 525 turbo gearsets were 4560 steel with a fine tooth pitch for noise. The 555 gearsets were 9310 steel with a coarse tooth pitch for strength.

555 & 568 manual transmission gearsets... 

The first couple of years they came from Getrag. From then on, they came from New Process gear in Syracuse, NY.

On tires running into things...

"I noticed yesterday that while parking my SC, at full right, the inside of the driver's side tire rubbed the transmission I just installed. I guess this is a sure sign that the motor needs to be shifted to the right (passenger side)?"

No, Greg. This in fact maybe normal. The trans cover was considered a "friendly" interference when that packaging study was done.

Down n' dirty automatic transmission repair...

"My trans was recently rebuilt but it is doing what it was doing before, it is sticking in third when it comes to a stop"

This will sound scary but it was done regularly in the trans lab at Chrysler. The reason it sticks in third is because the trans governor is sticking. To unstick it (this is the scary part) get the car moving about 25-30mph. Then momentarily put the shifter in park and then back to drive. The governor is bolted onto the parking sprag. When you try to engage park while moving the park mechanism will ratchet very quickly shaking the governor valve loose. The whole trick to this is to be moving fast enough so park will not engage. If it still sticks the valve body will need to be removed to gain access to the governor and it should be cleaned or replaced if necessary.

On Neon gearboxes!!

I'm not sure the 555 style gearbox would fit. I know the internals won't fit because the Neon trans is the same as a Chevy Cavalier not the old Mopar design.

On GLHS 525's

The torque was limited in the GLHS to 175 ft. lbs. because of the limited torque capability of the A525. I can remember Engineering screaming about going that high. Remember the 525 was designed back in the late '70's for a N.A. 2.2 liter making 85 ft lbs of torque. The engine could make 200 ft lbs easy.

REALLY expensive transmissions!

The Super Touring engines cost about $48,500 each and an Xtrac trans is about $60,000 to $70,000 each (no typos here. The Xtrac's are about sixty-thousand dollars).

On Turbo III engines.

Where did the Lotus TIII cylinder heads and induction hardware come from??

The components were supplied by Lotus and ASSEMBLED by Chrysler in Mexico.

On 16V Maserati heads on a 2.2...

"I was just wondering how hard would it be it adapt the Maserati 16V head to a 2.2 block. Has anyone ever tried this? What parts are needed (besides the head and cams)? Also, how about the Maserati 16V vs. Lotus 16V head. Which one flows better? Which one is more feasible to put into an L-body car?"

From what I remember, the timing drive, exhaust and intake manifolds, the turbo (could probably make something else work) the pistons, rods and crank are different. The block is machined slightly different but you could probably improvise. The Maserati piece makes a better race head. It does not have hydraulic lash adjusters. It's cam over bucket like a VW rabbit engine. I doubt that either one would bolt in without some fabrication on the intake side because of the tight space in the front side of the engine in an L-body. The Maserati wouldn't be as tight because the head isn't so massive as the Lotus head.

The Maserati is a much better head. The Lotus head has poor ports and the hydraulic lash adjusters give some trouble and then there is the cracking problem. If I had the choice, I'd use the Maserati piece. It's just better.

Turbo III timing belt adjustment...

The only way to set the T3 belt correctly is with a tension gauge. Even when using the one shown in the service manual the procedure is not very repeatable. The belt tension meter that is used at Engineering reads the tension in hertz. The belt is tapped and the frequency the different pulley-to-pulley spans vibrate is then converted to belt tension. This is the method used for all timing belts and is repeatable down to 2 Hz. The belt tension gauge in the manual will allow you to get it close. Using a trial-and-error method is risky on the T3.

On magical hp increases with motor oil...

The long awaited test of the magical crankcase elixirs has been completed.
Is there big horsepower increases available by using the right potion?
Will the fortunes of those with stock in Royal P. and Redline skyrocket?
Or will a major oil company be the horsepower winner?
Continue on here and read all the horrifying details.

The tests were run on the same day using the Super Touring engine. The baseline lab 5W30 was run between each of the other oils. The engine was run at 4800rpm @ 100lb-ft of load for one hour, drained and refilled with the lab oil and run for another hour. This was done to purge any residual test oil in the system from the previous test. Several power runs were made and the data averaged. The area under the torque curve was numerically integrated to determine which oil produced the greatest area under the curve. The baseline was set using the 5W30 oil that is used in all testing. The dry sump system and engine was drained and purged between each test. Redline 10wt was tested next. Then Redline 20wt, Royal P 21 and 11. Then Texaco Havoline system 3 5W30. Finally the lab oil was run to reestablish the baseline.

The winner by a huge margin: Havoline
It produced an astonishing 0.23% more power than the lab oil. This is enough to raise your 300hp engine to 300.6hp! WOW! I can see the lower ET's already! Better buy a helmet for your next trip to the track. The loser: Royal P only managed 0.008% more power than the lab oil. Actually the percent error on the dyno is higher than differences measured. I'd call it a wash.

"There ain't no magic in a bottle.
DaveZ. 1998"

Production nit's, picks' fact's & figures.

How boxy is that brick?

The Omni's cd is 0.44.

And where the hell did they come from?

All Omni's of every persuasion were built at the Belvedere, IL plant.

On 3.3 V6's stuffed into P-bodies (Shadows)

 The 3.3L will fit if it is the late model P-body with the V6 engine box. We did one at Engineering several years ago. I was some combination of C-body and P-body stuff.

On domestic-import 3.0 V6 Turbo engines..

Actually, a 3.0L turbo V6 Daytona was a program in the late '80's. There were probably 6 prototypes built. They ran very strong. Unfortunately, the program was cancelled.

On radiators loosing thermal efficiency...

My question to you is "How old is the radiator?" Radiators lose efficiency from both the inside and outside overtime. Inside is due to material coating the tubes and exterior is due to corrosion. In the north where I live, I'd change the radiator if it's over 5 years old.

Speaking about that thermal efficiency... how about then engines?

You guys are thinking waaaaay too much. The reasons for the engines being painted is simple. There was an underhood committee. They decided that underhood colors would be black and silver. That's the reason. No rocket science with respect to temperatures or emissions. They just decided it would be black with a natural color cylinder head.

On making things fit...

"I checked the size of the exhaust piping on my '88 Daytona Shelby Z. It had 2.5" pipe from turbo to cat, 2.5" from cat to just in from of the rear wheel well, 2" from there to muffler. My exhaust system is 100% stock. Does anybody know why Chrysler 2" pipe from the wheel well aft other that to save money?"

It's to provide the recommended clearance for manufacturing and assembly. Manufacturing dictates alot of the clearances needed for working room when the car is assembled on line.

Turbo bypass valve (BOV)

I know there is a lot of misconception about the turbo bypass on the later model turbos. This was installed STRICTLY for noise. Not quicker spool up. Not turbo life. Everybody at Engineering took these things off of their car because they tended to leak boost pressure back into the airbox and have the turbo work harder trying to make it up. I won't say that there MIGHT be some other benefits but that was not the intention of the factory.

Now where did that pesky Turbo II engine come from?

At Chrysler Engineering back in 1984 I oversaw the build of 25 Turbo II Daytona's. They were the cars that all
of the testing was done. The Shelby operation just pulled the parts into their operation a year ahead of regular production. I can guarantee that the Turbo II was designed entirely in Highland Park.

On the electronic controlled suspension that never showed up in 1990...

Dave: It was cancelled before the cars went into production. I knew the engineer who worked on it for 2 years. He quit after the option was cancelled. There were a lot of problems with the connections at the shock and struts. 

"Can you please explain how that one got built then?"

It may have been a car that had been modified in Engineering and accidentally got sold or possibly a pilot or show car.

"It sure didn't look like a prototype or any form of test mule. Could it be it still was one though and had a VIN?"

If the car got built in the plant during pilot, it might be possible it got out the door. Probably the guy got the parts that were going to be scrapped and put them on a car. Who knows?

How to center your engine...

To center the engine loosen the four nuts that attach the front mount bracket to the body and the two passenger side mount bolts that attach the mount to the body. This may seem like a lot of work but this is the way I center my engine. With the bolts I've described loosened, I have the car with the front wheels off and the lower control arms on jack stands. I remove the axle nuts from the driveshaft and measure how much each axle can be "plunged" inward. I pry the engine to get the amount of axle "plunge" equal on both sides then reassemble everything.

MP computers & parts.

On MP computers..

The reason some don't have feedback is idle quality. The engineer who did them likes a smooth idle and the richer idle mix helps engine throttle response.

There are some changes at part throttle also. There is more spark at idle and fueling is a little different there if I remember correctly to help idle quality (my boss is a stickler for this stuff and he's the guy who did the turbo MP modules). The wastegate control is more aggressive. The wastegate is held closed sooner and longer but this will really only be noticed at WOT. He's conservative with the calibration for these modules but I don't think anybody burned any pistons with one if everything else was functioning correctly. He didn't do the Shelby modules. Alex Koral at Shelby did those with some assistance from the guys back in Detroit. Those calibrations appear to be more on the "edge".

MP springs and lifters...

I don't work at MP so I don't know what the superseded S-60 springs are. You don't need the high rpm lash adjuster if you don't aerate the oil. They are "supposedly" splash fill. Don't ask me to elaborate because they are an MP part. I've never used them and never had a problem with the production lash adjuster.

A 16V head was never available through MP. You might just be thinking of the pictures that were in the catalog of a dual Weber 16V 2.2. That engine was run back in Engineering about 1982. It was a Ford Cosworth head modified to fit a 2.2.

Automotive mathematics...

On light wheels...

"I'm surprised I actually read something interesting in this magazine, but has anyone picked up the June issue of Sport Compact Car? There's an editorial called "technobabble" that explains the theory behind rotating weight. We've all heard that "one pound of rotating weight (on the wheels) equals more than three pounds of weight of the car" because that weight is rotating weight, right?"

It's really related to the moment of inertia. Inertia is not based on the mass as much as geometry. Think of an ice skater spinning during a performance. I'm sure you've noticed that they can spin faster by tucking their arms and legs in. Their mass is exactly the same but by pulling in their limbs they have reduced their moment of inertia. In angular acceleration "torque = moment of inertia X angular acceleration" Therefore " angular acceleration = torque/moment of inertia" Therefore the lower the moment of inertia, the higher the acceleration will be. I really need the Greek alphabet to do this correctly!

On rear disk brakes & brakes in general...

About rear disc brakes...

I ran the '89 rear brakes back in '87 (this stuff is usually being tested 3 years before production) w/G-body master and H-body prop valve. I used the '86 G-body front caliper. I've never had a problem with the front brakes. I'm not saying it wouldn't be nice to have more brake but they always seemed more than adequate. No, I couldn't use the brakes at 10 tenths when road racing but I never expected to. They're not racing brakes.

A good 63% of the weight is on the nose of the car statically. Under hard braking it's probably more like 80%. I just don't think that adding discs to the rear can be a big benefit. When Team Shelby was racing the L-bodies in the Escort endurance series, the rear brakes were good for 8-12 hours depending on the track. The fronts were good for 1.5 to 3 hours. There were times when we had problems with the rear adjusters (eventually got rid of them) and we would lose the rear brakes. We'd pinch of the brake line with a visegrip and send the car back out. It didn't affect lap times enough to worry about it. I'm sure this is much different in a sprint race where you use the brakes at 10 tenths but I still find it difficult to believe that there is a substantial lap time improvement over a set of drums that are working properly.

More on the rear disk brake thing...

Been there, done that. I had 4 wheel disc brakes on my L-body back in '87.  They lock up prematurely unless you can get a proper prop' valve. They look cool. Do they help stop quicker? No. Since there is more rear brake bias with the discs than the drums it feels like they stop shorter and maybe they do. BUT if you changed the rear bias on the drums they would do the SAME thing. Plus the drums weigh less and the tendency for the brakes to drag is less. Front drive cars don't need 4 wheel disc brakes.

More on rear disk brakes and Shelby....

The rear disk brakes on the Shelby stuff was just pulled ahead from the '89 production 14" four-wheel disc brake system. I used those same rear brakes on the '87 LeBaron Indy Pace Car. Most of the Shelby stuff (you guys can believe me or not) was just pull ahead production Chrysler stuff. We had Turbo II's back in '85 in Engineering. The A555's weren't available yet so all of the cars had 525's with what is now the MP girdle package. Shelby just pulled these parts and put them into production earlier in his small operation. Don't think the Shelby Dodge center did all the engineering for this stuff because they didn't. They did develop the packaging and sourced some unique parts like the Koni's, and figured out what it took to get it into an L-body, P-body or whatever.

"Are you saying that Ma Mopar developed the internal shoe emergency brake and gave it to Shelby FIRST?? Then it took 2 years to make it to one of Ma's cars?, after all the problems had with the "wedge" ones? Doesn't sound quite right here..."

That's correct! DaveZ

On weird van brake rotors...

"What are the best brakes that I can fit on my L-body and still retain my 4-lug 13 in wheel tire combo? I have $500 worth of new wheels and tires, and $150 in new bearing/hub assemblies. I was planning on swapping '84 K-car rotors, calipers, and brackets on, this would at least give me ventilated rotors. But what about early four-lug minivan brakes, would they fit into my wheels? I understand that on 5-lug cars, the rotors are the same for GLH and minivan, but the minivan calipers are just bigger, is this the same on earlier four lug minivans?"

Unfortunately, I think the only thing that will fit in the 13 inch wheels are the '84 K car stuff. I'm not positive about this though.

One thing about the minivan rotors. They are actually thinner then the K body stuff. This allowed them to use a thicker brake pad to try and get some reasonable brake life.

Aftermarket- extrude hone, rods, electromotive & piston coatings.

On Extrude Hone...

I spoke with a casting supplier awhile back and the reason the Ford intake is Extrude honed is because the design was so bad it wouldn't flow and it was too late to retool it. It was the only way they could fix it. The Chrysler flow room techs don't like the process because it doesn't take the material off just where it needs it. It takes it off everywhere. DaveZ.

On aftermarket connecting rods...

I really like Pankl's or Carrillo's. We used both in the Super Touring engines. The Pankl's were lighter but the big end would go out-of-round after awhile. The Carrillo's were heavier but were bullet-proof.

Electromotive Fuel Injection

This stuff is the spec engine management system for TC2000 (a race series in Argentina). I've worked with it for the past couple of month and I don't see anything great about it. The only feature I see is that it allows YOU (the guy on the street) to adjust your fuel and spark. It is not as sophisticated as the factory system. It doesn't give you as many break points as the stock system. Our stock system (1998 vintage) is worth 15hp over this system. It just doesn't have the adjustability that the production system has ( if you know how to adjust it). Also the sensors are very sensitive to noise. I had a hell of a time trying to solve a misfire problem. In my opinion the technology is at least 15 years old.

Ceramic coated pistons and the other piston questions

I've been through the various coatings, testing them on the touring car engine and found no gain that can be measured. I've tested coated rods, pistons, blocks, cranks, valves, ports, heads, bores, pumps and haven't found any MEASURABLE performance increase. I'm only looking at an increment of 1/2 lb-ft. That's as small an increment that I can repeat on our dyno. The only coating that has worked is one that we use on the bearings. It helps durability.

In my experience, these coatings on pistons keep more heat in the cylinder and make it more detonation prone. It hasn't worked in the Touring Car engines.

Historical tidbits.

Where did all the 2.2 stuff go??

Chrysler doesn't have the 2.2 tooling anymore. They sold it to the Chinese who put them in Audi's they build.

The "Ultimate" Daytona...

It was called the "Ultimate Daytona" and built for Bob Lutz. Mainly built for the autobahn from what I heard. It was a 1990 2.5L bottom end w/ Turbo IV production rods, and production 2.5L pistons. The only trick piece was a billet copy of the stock 2.5L crank made by Valasco. The cylinder head was all production Turbo III. The turbocharger used was a Mitsubishi TD06 turbocharger - the same unit that is on the GMC Syclone Pickup. They used 50% higher flow methanol injectors and the fuel pressure was set to 55psi. The boost starts out at 14 psi and ramps, beginning at about 5200 rpm to a final figure of 19 psi at 5850 rpm. The engine used twin stock Turbo III intercoolers. This engine had the potential of spinning at 7000 rpm and pump out over 426 horsepower. When the engine was in the car it reached a speed of 155 mph, but it was estimated to go to 170 - 180 mph. Zero to sixty times were estimated at low 5's to high 4's with quarter mile numbers registering high 12's to low 13's.

On driving the "Ultimate" Daytona

I drove the "Ultimate Daytona" at Milan dragway the weekend before it was dismantled and scrapped. It ran a best of 13.40 @ 104mph.

About dem 200 mph Lebaron coupes

It ran the 425 hp engine from the Team Shelby IMSA GTU car that we ran in '87 and '88. It was a 2.0L turbo developed in Engineering at Highland Park. I used to spend my lunch hour at that dyno cell.

On 4wd Turbo Daytona's...

This thread ran once before. (4wd 2.2 turbo's at high hp levels) Don't try it. Pete Gladysz and Doug Sheperd tried it several years in a Daytona and couldn't make it work.  They had a lot of resources to do it but it is a BIGGGG tear up to the car and the drivetrain.

And no the 3.3 trans won't bolt to 2.2. You would need to get a Mexican 4spd auto case and put the 3.3 guts in it.

But what about the one we saw in the magazines in 1985?

The Daytona-4 used a totally different setup then the minivan uses. The PTO unit will bolt to an EMPTY A568 case but the diff won't work. The input to the PTO is splined to the differential housing casting. The manual trans diff case is not splined and the diff from the auto might work in the manual with some machining. The AWD minivan has special knuckles (the steering rack is raised), special crossmember (a driveshaft goes through it). You'll also need to put a hole in your gas tank for the driveshaft.

On 151 mph Indy pace car (1987)

I was the project engineer on the Indy LeBaron. Four cars were built, one is in the Chrysler museum, one is at the Indy museum and Al Unser, Sr. has one. I don't know where the last one is. I still have the spare keys for all four of the cars.

Why were turbo's whacked?

It was the EPA. They were threatening to have the engines run stoich at WOT for some period of time. A turbo engine won't live under those conditions without exotic materials. So when developing the new line of engines turbos were not part of the plan. Mexico went and did their own but they don't have the EPA to contend with making threatening to make outrageous rules.

On the Team Shelby GTU car...

The block used in the GTU engine was a production based "common block". The cylinder head was cast in the Casting Lab at Highland Park and was much thicker in the deck area and had raised ports. The Turbo III head is a much beefier piece than the two-valve head and would handle the extra power. The crank was a billet piece and the pistons were forged Mahle's.

300 hp Neon engined dragster??

 Danny has run an 8.51 @ 151mph. The car only has about a dozen passes on it. The engine is a modified version of the Stratus Touring Car 2.0L. I spent a week in Phoenix at his shop getting the engine wired and calibrated. The car will be here in Michigan some time soon and I'll spend a day at the track with it doing some further development.

Thank you for visiting Donovan's Dodge Garage