ITS Ford Mustang(s) Build - Stripper Stang Part II

[Ron Earp]

So we went from bare block to this:



In somewhere around 30 hours or so, roughly. Actually, that is a bit long. Of course there was some beer drinking in there somewhere, got to have time for social activities.

After consulting with all the exhaust gurus we settled on a new exhaust design. It was fabbed up by R&J in Apex NC and we painted, baked, wrapped, and installed it last night. It has proper sized primaries, collectors, and merges unlike the old one that was a hodge podge of design and off the shelf parts. The best thing is that it is 18 lbs lighter than the old design. Always look for places to get some weight off. I'll try to get some pictures of that up later.

I summary, the red car has a new motor to try out at VIR and I'm sure it'll be better than the last one. The old motor didn't have a 0.5 compression hike, was 4 oz out of balance, had an imbalanced drive shaft, had inferior rings, and probably wasn't torque plate bored although it was supposed to have been.

[Ron Earp]

Another update from the Stangwerks….

We got Jeff’s new motor in the car and running without incident. And, we headed out to VIR for the March Memories race and test day early Friday morning. On the initial session a problem reared its head, one that we’d experienced before – a driveline vibration. Jeff reported it was very bad and since the motor was new, and we knew it was properly assembled, we immediately figured it was the driveshaft. So we swapped the driveshaft from the green car, which has never had a problem, and put it into the red car for testing. Next session out the problem was entirely eliminated and the car ran well. Smooth, powerful, good water temps and oil pressure, so all was good with the motor.

So Friday noon I took the old drive shaft down to Russell at Triangle Driveshaft in Durham and they fixed it while I waited. It was horribly out of balance due to a poor balance job at a shop in Raleigh from Fleetpride. Anyhow, Russell fixed it up and I returned to VIR to install it into my car. A couple more sessions out in the red car for the test day, some adjustments to rear roll center and shock dampening, and we decided we were on for the weekend.

Saturday morning came a bit too early but we were ready for qualifying. The ECR group qualified first with Zsolt’s Acura Integra taking the ITS pole. The Mustangs were not far behind though in second and third, although the field was a bit light. The SARRC qualifying order was a bit different with Jeff G. putting the Mustang on the pole I think, but I can’t remember the rest of the field. I think I started third. Anyhow, we were pretty happy with the results although again, the field was pretty light on strong ITS competition. Jeff Young had a problem with a front wheel hub disintegrating and got no good time, Chuck Hines was not racing on competitive rubber and wasn’t running as fast as normal, and a few others had dropped out.

The ECR on Saturday was a lot of fun. Jeff G and I were in the red Mustang, Robert Mitchell and Jeff Young in the green Mustang. Zsolt’s co-driver Trevor set a strong of smoking laps at the start of the ECR. Not one, but five or six 2:14s and I think one of them was a 2:14.0 according to my RaceMonitor app. Smoking, and says a few of things – prep matters, driver matters, and FWD can flat out get it done – kudos to them for building such a fast car and driving the hell out of it. The ECR progressed with the red stang second, the green one third, and then Zolt’s Acura had a hub failure and was retired from the race. That left the Mustangs with a one-two ECR finish, but I can definitely say if Zsolt hadn’t had the wheel failure they would have won the race as we were tuning no higher than 18/19/20 in ECR trim. Also in there was a smoking fast ITA Ford Focus by Mike Sperber so the Fords had a pretty good showing in the ECR.



After the ECR we retired to the paddock to work on the TR8 which was still laid up with a bad hub. We also worked on Chris Dercole’s Mustang and trying to help him sort his oil control problem, however, it was pretty reasonably clear he had bad rings and no amount of work was going to help. Car work done we retired to the Tavern with the crew and had a bonfire party later that evening. Unfortunately we forgot about the time change and Sunday morning came quick. Ow.

The SARRC came and went pretty quickly. A sprint race ain’t no ECR and it was over too fast. At the green it was Jeff G, Ron E, Chuck H, and Russ B., but at T1 Chuck got a clean pass in T1 on me and assumed second place. Later that lap or the next, Chuck passed Jeff G and was in the lead, Jeff G second, Ron E third, and Russ fourth. However, I could tell that Russ had more power than me and was gaining on the back straight so I figured it was a matter of time before he got me. Mustangs have good brakes, great midrange, but on the top end the RX7, TR8, Acura, etc. seem to do better. Russ got by a few laps in and it was Chuck, Jeff, Russ, Ron with me dropping.

Five or six laps into the race we were all coming into Hogs Pen and someone had tracked mud and straw all across the track. It had just happened and was in a place you couldn’t see well, therefore, Chuck had no choice but to hit it first and he went off track. The other cars managed to stay on track but the mud reduced everyone’s speed through that corner for a couple of laps. The race finished Jeff, Russ, Ron – first SARRC race win for a Mustang, although not for Jeff G since he’s been racing for 10+ years. We didn’t have the fastest cars on track for that weekend by a long shot but it was reliable and most importantly fun. And, as mentioned, we were missing a lot of regulars with two of them at the track, Zsolt and Jeff Young, not being able to race because of broken or wrecked cars.



Now, what was fast was the Mazda MX5s – have a look at those times, they were running 2:12, 2:13s, 2:14s all weekend, fantastic. Now the track was fast for the March VIR race, but those cars are getting it done. At the start of the SARRC they blew away the field. Jeff and I were right behind the two MX5s when the green flag dropped. I thought for sure I'd pass one on the start because they wouldn't have power. Nope. They dropped the stangs like a bad habit and gapped us all the way to the braking zone. We managed to follow them around but they moved out on the straights.

[Ron Earp]

And on the technical side, work continues at Stangwerks. We’re putting together motor number four, the second motor for the green car. The green car’s engine is still running well but the build is not of the quality of the engine in the red car. Len Hoffman from www.hamheads.com is doing the flow work and head prep for this new engine, while the block prep was done by a local machine shop. There will be a number of differences between this motor and what is in the green car: max 9.5:1 compression, good head work, torque plate bored, piston clearances, aftermarket OEM pistons (required, Ford doesn’t supply a 0.040” over), better ring package, carefully selected rods, different strategy for setting up the pushrods/lifters, and a few other changes.



We hope that this engine will perform better than the one in Sleestak. The red car’s engine is doing very well, although we are not generating any more top end speed at VIR. The mid-range we have is fantastic and we are probably in the upper percentile for off-corner power. But at the end of VIR’s back straight we won’t be doing much more than 123-125mph. I suspect the frontal area and Cd is just something we can’t get around. We are contemplating one more rear gear swap and avoiding fifth entirely because we can clearly see that when we have to use fifth the game is over, but that would cause us to have to use second in a couple of places on track and containing wheel spin with the high torque multiplication of second is going to be an issue. Anyhow, for the time being I think we’re going to struggle a bit on tracks that require a high top speed – VIR and CMS come to mind, we got nothing for the Acura and TR8 unless we manage to make some time in the short bits.



Lately we’ve been having a lot of problems with the red car and communicating with the ECU. We think we have it figured out, but in doing so we created a test rig for the bench where we can hook up an ECU outside of the car and program it. Dr. Giordano was the major motivation behind this job but it’ll definitely help us out for the future. We’re planning to mount it on a panel with switches, not this rigged up mess here, so that all you need to do is connect it to 12V, connect the laptop, and you can do whatever you want with the ECU. Programming the ECU in the car is what we generally do but this will help us prepare spares and test stuff out. We’re also planning to equip the ECU with an external EPROM so that we can load five pre-defined tunes into the ECU and switch them with a rotary switch, no laptop or reprogramming needed. The ECU program we’ve developed fuels very well but every now and then it needs a tweak. If we had four tunes with air fuel and timing targets, like 12.4, 12.8, 13.1, 13.3 we could quickly adjust up what was needed based on visual info off the wideband.



Work on DR COOL is progressing too. DR COOL is getting a dual peltier device engine, better insulation on all lines, a much better R value water reservoir, and an overall much lighter package even in comparison to the traditional water/ice cooling system. The goal is to have DR COOL in the car and functioning for the April RRR race.

[Ron Earp]

And we did a bit of clean up in the Mustang parts warehouse. I think we have enough parts above my garage to build another Mustang.





Took some different head castings apart for exploration. There are a good number of heads to work with on these cars, although the differences among them seem to be minor. Len has the "best" heads from what we can tell.



The number of blocks Ford has used, now that is a pain in the ass. We have discovered at least three different types of blocks for 94-98 MYs. No advantages among them that we can tell, but you've got to keep them separated because their critical bolts are not interchangable. We have sorted them into:

A - large coarse man cap bolts, short head bolts

B - small fine main cap bolts, one row short head bolts, one row long

C - smal fine main cap bolts with provisions for windage tray, long head bolts on both rows

We prefer "C", but it appears we've only got a pile of As and Bs, with both new motors having to be built from As.

And we got the Torino fired up and ready for the street.



However, the Torino could not hit the street. We worked with a local Ford guy in Mebane NC to have this motor built. But, he went too racy on the cam and what we've got is a big block Ford with all forged internals that wants to rev to 7k+ but won't idle worth a damn. We worked with the carb for 3-4 hours on adjustments to try and get it to idle but at 2k, running smoothly and purring along, it only generates 14" of vacuum. When the RPM hits 1500 that drops to 10", and as soon as we try and go lower the vacuum becomes non-existent and she won't run. Timing, fuel, idle, it seems that nothing will do the trick. But holy hell, rev this thing up and it sounds flat out awesome, like a NASCAR screamer. Anyhow, new cam and intake manifold on the way that is reported from a BB Ford builder and guru to cure this issue.

+------------------------------+

I've had a couple of people comment to me on the huge amount of time put into these cars and the relatively rapid development. No doubt, we spend a lot of time on the cars but having two cars being built at once provides more that twice the amount of development data. And it is less than twice the work. In looking back over the last 16 months we have disassembled three SN95 cars for parts, taken apart seven 3.8L Ford V6s of various years, built four race motors, built five rear ends with four different ratios, tried two different traction devices, tried out three types of brake pads, developed 20+ ECU tunes, dyno tuned at least five times, rebuilt two transmissions, run multiplr track widths, changed out springs rates four times and always going up in rate, Lots of changes in camber/caster/toe/corner weighting and had three separate exhaust systems built plus a lot of other things that I can't remember. For a single car/single driver team, in particular an oddball, this might normally take much, much more time. All I know is you're never at the end of development for an IT car although we're looking for the pace to slow down a bit.

But not yet. I'm out to Henderson at the crack of dawn to get a 2001 dual port 3.8L V6 as used in the ITR cars. Got an idea.....

[Ron]

Ron keep up the work. My parts area looks like yours. I have rows and rows of tried and failed parts. And the different motors, the 2.3 is just as bad. We have 3 race motors in development all the time and every block is different from ford. No real difference in "power" just little things that make them all their own.

I have had to take some time off from the car. Kids in college demand a ton of $$$$$$$$. I mean metric tons of $$$$$$$$. But we will be back, maybe with a different car powered by the same motor.

I am very lucky that I have great friends who have offered rides in their cars while mine is dormant. Wonderful friends.

[Andy Bettencourt]

Best build thread on IT.com

[Ron Earp]

Best build thread on IT.com

Thanks, we're trying to keep the fans happy.

Ron keep up the work. My parts area looks like yours. I have rows and rows of tried and failed parts. And the different motors, the 2.3 is just as bad.

Man, Ford is bad with parts. I just was reading through some of my info last night and Ford had used, up to 2001, ten different blocks for the 3.8. The variations are slight and mean little (other than the FWD/RWD distinction) but can create headaches for building engines and using parts on hand.

The 1999+ split port 3.8L engine is one hell of a motor. We got one yesterday and disassembled it to have a look at what it is all about. Mostly it is the same as the 3.8L single port motors like we have, but the heads on this engine can really breathe. They have two intake ports and larger valves to boot. The exhaust ports are tiny, but, they are way undersized for the gasket and unless the water jacket is a problem they could be improved even under IT rules. The motors are internally balanced therefore the crank is different than our engines.

Anyhow, for ITR I think these motors could really put down some power. They are rated at 190hp from the factory but they would see significant gains with a proper IT build. However, my main reason to purchase it didn't pan out so well. I wanted the windage tray from this engine since the 94-99 units are NLA from Ford and we're out of them. But, this motor is a 2001 and Ford decided to change the windage tray unit to be a stud girdle/windage tray that I can't use. At least the front cover was the same though and I can use that. Front covers are fragile and we've a pile of cracked ones.

Ron come to one of the race weekends and you can have a drive of the Mustang on a test day or race. I think you'd find it to be like your ITB car, just with a little more power. After all the underpinnings are essentially the same, very honest handling and fun to drive.

[Ron Earp]

Best build thread on IT.com

Thanks, we're trying to keep the fans happy.

Ron keep up the work. My parts area looks like yours. I have rows and rows of tried and failed parts. And the different motors, the 2.3 is just as bad.

Man, Ford is bad with parts. I just was reading through some of my info last night and Ford had used, up to 2001, ten different blocks for the 3.8. The variations are slight and mean little (other than the FWD/RWD distinction) but can create headaches for building engines and using parts on hand.

The 1999+ split port 3.8L engine is one hell of a motor. We got one yesterday and disassembled it to have a look at what it is all about. Mostly it is the same as the 3.8L single port motors like we have, but the heads on this engine can really breathe. They have two intake ports and larger valves to boot. The exhaust ports are tiny, but, they are way undersized for the gasket and unless the water jacket is a problem they could be improved even under IT rules. The motors are internally balanced therefore the crank is different than our engines.





Six intake ports, three cylinders. We're going to keep the parts around for the possibility of building an ITE motor for the stang we have, or maybe one day building an ITR car. Anyhow, for ITR I think these motors could really put down some power. They are rated at 190hp from the factory but they would see significant gains with a proper IT build. However, my main reason to purchase it didn't pan out so well. I wanted the windage tray from this engine since the 94-99 units are NLA from Ford and we're out of them. But, this motor is a 2001 and Ford decided to change the windage tray unit to be a stud girdle/windage tray that I can't use. At least the front cover was the same though and I can use that. Front covers are fragile and we've a pile of cracked ones.

Ron come to one of the race weekends and you can have a drive of the Mustang on a test day or race. I think you'd find it to be like your ITB car, just with a little more power. After all the underpinnings are essentially the same, very honest handling and fun to drive.

[Ron Earp]

And gotta bust it up into multiple posts due to limit on pics. Anyhow, Jeff is still analyzing the data and looking for resonance effects from various vibrational modes.

[adamjabaay]

these have to be the two most developed cars in IT history. Truely inspiring, and intimidating, stuff ron and jeff.


unbelievable


what sort of go-faster-ness data come from the vibrational analysis.... Your way over my head!

[Ron Earp]

And more vibration analysis has been happening. This is from last weekend and fitting the chassis with three sensors as well as an RPM pickup to monitor the chassis, engine, and tranny throughout the RPM range.

[Ron Earp]

Been a long while since any updates but development has been continuing heavily over in the Stangwerks. Back in the May time frame we spent a lot of time at the dyno over two separate sessions. What we were trying to do was get the MAF transfer function to precisely fuel the car over the entire RPM range and pick up gains from our new exhausts. With A/F close doesn’t cut it because we do see differences when we’re off by 0.2 A/F ratio, and obviously as the difference becomes greater the power variation is higher.

Here is a plot from logged data in pulls through a couple of gears. As you can see the A/F drops a few tenths of a point over the RPM band. As the mixture gets richer the power tends to drop off and we end up with holes in the power band.



Here’s a close up example of what I’m refering to, with an original and corrected power curve in a fairly narrow 800 RPM wide window. In this particular section of the curve, down in the 4k region, the original pull was deficient about four horsepower in this section. And, this wasn’t the only area of the curve affected as there were a few other areas that needed attention. When we can get the engine to run consistently at the target A/F of around 12.9 it is noticably sharper and pulls with more authority throughout the RPM band.



The way we fix it is by re-mapping the MAF transfer function and shifting the limited number of cells for the curve to the RPM range of interest. As develiered the Ford ECU has most of the resolution of the curve focused in the 0-2500 RPM range and have very few points above that RPM. Furthermore, the Ford ECU V has adaptive learning so it starts to correct these values in the trasnfer function so that the operable RPM range becomes extremely well behaved.However, our operation is entirely different. We are only interested in WOT and the adaptive learning doesn’t not function at WOT, and, we don’t care about low RPM operation. What we do is use more cells/points in the 3000-5500 RPM range, thus allowing higher resolution there and more accuracy for delivered fuel.



The ECU can still apply modifiers based on intake air temperature, coolant temperature, load, and a few other things that affect the ultimate fueling. And we’ve learned the hard way that these modifier tables themselves need doctoring because they can be too intrusive to the detriment of power, however, they can be completely shut off. Anyhow, the end result of the work was that we had two independent MAF transfer functions, one for each engine, that performed far better than what we had at the outset. At CMP and RA we had dead nuts accurate fueling that resulted in more horsepower area under the curve.

We still haven’t had time to get one of the cars down to the chassis tuning dyno but I hope we have time in September. Our new trilink in the rear is behaving wonderfully and we’d really like to see some hard numbers, measured instead of calculated, to go along with our efforts.

[Ron Earp]

Besides the handling and exhaust, we’re still doing a lot of ECU tuning, particularly with modeling the mass air flow transfer function to fine tune fueling in all conditions. We’re also starting to play with individual cylinder spark timing for each cylinder, a la this excerpt from a presentation on optimizing engine power.



In talking with Jeff G. he knows someone with experience in making the pressure measurements needed to figure out what the optimal timing is, and he's got access to the modified spark plug pressure sensors and data collection equipment. So we might try and make some measurements on the cars to see if there are any gains to be hand. Curiously enough the stock Ford EEC-V that we use to control the motor has individual cylinder trim spark timing, -5 to +5, with user definable RPM ranges these would take effect within and modify the commanded spark valve. That Ford built the functions into the ECU in the first place seems to indicate it might be needed for some certain applications, however our trim tables are all set to zero with no modifiers being used.

And in doing this work we've had numerous dyno sessions over the last couple of months. I think we've probably gone four times this year just to test ECU and tuning parameters. Fortunately we've got a great shop to work with where we can show up, strap down, and run the cars at generally $100 / hr. We always have our testing regime and files created ahead of time so we can get five or six tests done in that time. And we'll need to go back for the exhaust and maybe spark studies if we get that portion checked out enough to take a stab at it.

Work continues. There is always something to do.

[Ron Earp]

Development heavily continues over in camp stang. The new rear end geometry is working out extremely well and along with our properly re-valved shocks, plus a lot of testing, we’ve really improved our cornering and corner exits. We’re learning that the car is more sensitive to ride height than we initially thought. It is more complicated that stated, but it is sort of where 11-12mm in ride height can make the difference between a properly handling car and one with understeer. When it is spot on though the car handles precisely, with a slight tendency to oversteer, and is a great point and squirt machine.

Over the past couple of months we’ve been working with Burns Stainless and a header builder, Calvin Elston. We knew that our exhaust had some shortcomings and Calvin and Vince have conspired to design a system that would be our final exhaust design. So, after one of our race weekends I dropped the car off at the shop and waited about four weeks for the final product, and wow is that a nice exhaust system he put together. Exhaust V3.0 is really well done from flanges to tail pipe. There are a number of aspects about it that are greatly improved over the earlier headers; water jet flanges that precisely match the ports, lots of upper roof port flow, equal length to within 0.5", three newly sized collectors, newly sized primaries and steps, anti-reversion collector for the final section, and all made out of stainless that might also drop some weight.










It's hard to see from the pictures, but they are elegantly done although the equal length requirement means it's really tight in the engine bay now. There's a damn good reason why most header systems for vee motors, or long inline six engines, aren't equal length. The pipes just take up too much underhood real estate and are hard to manage.

It'll be dynoed to determine improvements, but out of the box one thing that is very noticeable is the sound. The motor sounds much smoother, crisper, with a higher pitched exhaust note. Greatly diminished is the rumpty rumble low pitch frequency exhaust noise that very much characterized the engine from the get go. It's not the kick ass sound of an inline six Z or BMW, but it closer to that and much more of a smoother wail at RPM.