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

[Ron Earp]

Kinda like Honda does it...

On the other hand, Honda doesn't have a chassis that supported 88hp to 390hp engines in a production car - oh, wait, Honda hasn't ever had a 390hp engine in a production car. My bad.

[lateapex911]

On the other hand, Honda doesn't have a chassis that supported 88hp to 390hp engines in a production car - oh, wait, Honda hasn't ever had a 390hp engine in a production car. My bad.

they didn't NEED a 390 hp engine. Their chassis and componentry were elegantly engineered and carried no excessive weight.

[JeffYoung]

Honda skimped out on the motor thought....

That's actually a TR7 brake disc, slightly smaller diamteter but you get the picture.

Ron, I will try to get by this week and get that stuff out of your garage. Last week/weekend got crazy.

Sorr you guys had so much trouble this weekend. I'm pretty much tied up on my car this week and net finishing it for VIR. Hopefully it will just need brakes for CMP and I can help you guys make the push for the test day at CMP.

[Ron Earp]

The front isn't all bolted together yet, but the spring geometry is much better. Now the perch sits on the pin cocked at an angle and directly points at the upper perch.



Furthermore, the new threaded inserts allow the use of a locking nut on the adjustment pin which improves the strength of the system. We do need slightly longer pins for good adjustment, but only 2" longer and it is only a $13 part.

Good news is that the original springs that I thought could not be used at ride height can be used, yay.

[Ron Earp]

Recent dyno plot I picked up from another dyno operator that had done some Ford 3.8L V6 work. This engine hasn't been opened and had some long tube headers, cold air intake, minimal mufflers but still cats, and some timing / fuel work. Not too shabby. 219 ft-lbs of torque and 148 hp, Dynojet at the wheels.



The torque curve rolls off fast thus the power takes a hit, but, I believe that with some serious header work plus all the normal IT-go-fast stuff we do we can get the torque curve to hang on longer and boost that power number. The torque and low-end power is clearly sufficient, the top 1000 RPM is where it needs a lot of work.

[lateapex911]

revs? Thing hasn't even done the 5250 cross yet!

[Ron Earp]

No, it hasn't. Been sitting on that one awhile actually. The hp peaks around 4100-4200 RPM. But I think we can shift that and designed our system to do just that. Mr. Young's TR8 was of similar output and RPM peaks way back in the day (maybe six years ago). I think some of the early dyno plots with it were peaking at 4XXX and the torque peak was on the way down at 3000 RPM.

I started researching these Mustangs in 2005/2006 and you'll find old posts of mine on Mustang forums during that time. I laid off it as I got convinced they'd never make the needed power, mainly due to the typically "Ford think" around the engine that convinced me they couldn't do the job. I picked it back up again in 08/09, bought a Mustang in early 2010 for ITR, sold that one based on a bunch of information I'd accumulated, did a bunch more research in 2010, and bought another Mustang in 2011. Here we are.

I still might not be doing the "right" thing building the car, but my research shows it has a legitimate shot. Ironically, the issue I thought I'd have, making enough power, isn't what I'm worried about now. I'm pretty sure we'll have the other heavy hitters in S covered with power and torque - 240/260/280Z, RX7, 240sx, 325, and on par with the TR8. I'm concerned about handling, mainly balance and turn in as well as front suspension travel. I feel the rear will be an advantage compared to many S cars, but the front, nope, not so much. It is an interesting experiment and one I hope doesn't end badly.

It fits with my theory though that I think others have also used, so it really isn't mine: get the largest lowest specific output engine in the class and build that car. Based on experience with other non-racing car activities and intimate hands-on work with the TR8 I'm convinced these engines, which are typically two valve large displacement low revving designs, are "growers, not showers", and have the best chance of seeing large gains in IT trim. For ITS that means the TR8, 300Z, and Mustang, and maybe the 280Z. These are the largest motors in the class with relatively low outputs. If I were a NISMO man still I'd be on the 300Z. I don't think I've seen even a 90% effort on one of these engines and suspect it could do really well with the open ECU rule, ditto the 280Z.

Incidentally, the rule seems to be what Andy and them have dopted in ITR with the Corvette, no?

[Ron Earp]

Good news, Ron's arms are done and wheels are here.





The Spinwerks wheels come in at 11.2 lbs on the certified scale, exactly as advertised. Sixteen of them all told. I think they've got the best deal going for a light wheel at an "affordable" price.

[Ron]

Stop copying me. Large displacement (2.3 L in IT motor that has possible big IT gains. Alomst the same suspension setups, and now the same wheels.
People are going to think we are dating or something!

[Ron Earp]

You run Spinwerks too? I used to run them on my Z as well. Good wheels. Yep, find big motor with low specific output and build it. A lot of stuff can be forgiven with enough horsepower.

[Ron]

Yes our bolt pattern (4x108) is tough to come by. They are great to work with, any offset you want, light, strong.

[MSPERBER]

Ford stuff is so weird, 2.3 liter but mine is front wheel drive, with the same bolt pattern but front wheel drive offset and I am in ITA at a very heavy 2680. It still is fun developing a new car but I am no where near as capable as what is being shown in this post. My goal was to run what I sell, Fords should be all over IT, 2.3 in ITB,ITA, and ITS . Maybe Ford is the new Mazda

[Ron Earp]

Ford brothers unite! We need to have more domestic terror out on the track. I'm hoping some of our long lost GM brothers will join us in IT as well.

You guys interested in taking a F250 in on trade for a new F150 Ecoboost?

[Ron Earp]

More work work work work.



Still haven't got the swaybar mount situation correct but we're a lot closer. I think with one more iteration of spot welding the pads on the chassis we'll get the distance correct, the lever ratio we want, and get it to function. Might require a bit of tweaking on the arms but we're close.



You can see where we've got about one more place to try there on the chassis where we haven't welded to it yet.

Clearly, we're not bringing the cars to VIR. CMP at the end of March is really iffy, but RRR in April is fairly solid at this point, although motors are yet to be started, tuned, and of course problems will arise there as well.

[JeffYoung]

I can help post VIR.

I'd suggest pushing on one to get it ready for CMP, take it down and split the test day and the SARRC.

CMP is a great place to test and RRR is a long way to go to fail.

[Ron Earp]

Won't ever turn down help, but we're entering that slow phase of lots of fabrication. Hopefully we'll be out of it soon, maybe by the end of this weekend. One thing we've got to do is build shelves upstairs. The Kingdom of Mustang is overflowing with parts and there is no method to the organization. That drives OCD Ron crazy.

[chuck baader]

Ron, I sure would like to see that sway bar rod end in double shear...easily done on the bottom of the frame rail. Chuck

[Ron Earp]

Ron, I sure would like to see that sway bar rod end in double shear...easily done on the bottom of the frame rail. Chuck

Oh there are lots of things I might like to see or change, but finite analysis showed it was plenty strong. That is a 5/8" rod end and accompanying G8 fasteners.

[lateapex911]

yea, thats interesting, Ron. To my eye, I went "Huh? That looks like its gonna fail". But, I know you ARE an engineer, and I am NOT. So yea, very interesting.

I always assumed the pivot point was the bar center. It would have never even occurred to me to do it the way you're doing it. I'm impressed! (and learning)
How much does that whole setup weigh??

[Ron Earp]

I'm the scientist and Jeff G's the engineer, and we bring in Jeff Young for the heavy legal and bolt stripping, therefore we're one of those synergistic fabrication teams that can do it all. We didn't design the bar but were impressed with the design. John and Bruce Griggs used it on their ITE road race cars with the same mounting design and they didn't fail. Their attachment of the bar to the arm is different from ours though as their race cars used tubular arms where as we have to use the stock piece, but the concept is the same. Just requires a bit of adaptation.

It is "reasonably" light. What is interesting is that the V6 Mustang front bar is hollow already thus it isn't overly heavy. The new bar is a pound or two heavier, but much stiffer, than the stock bar. The mounting hardware vs stock is about a wash. We've got some heavy heim joints but the stock parts had some damn heavy bushings that we don't have. The stock mounting brackets were very weak looking but worked, so if you don't like the looks of these do not drive a Fox car with a roll bar, you'd be scairt!

You know, maybe it doesn't work well but I think it will. One thing is for sure, if you do the same old thing everyone else does don't except to get a better result than they do. It is good to try new things.