Hey John,
I happened upon this thread through your link on SCCAForums. I usually never leave the race car tech section of RX7club. It is good to see your build. I have been waiting for someone to build an STS2/STS FC ever since James Wilson got rid of his GTUs a few years ago. If I ever get around to going from ES to an ST class I would probably build to STR, now that the rules are finalized (can keep my clutch type dif and run wider rubber).

Good luck with the build. It looks like you are well on your way to a competitive car. If you have not already search for James' threads (also under Turner motorsports iirc) in the Race car tech section. One of his main issues was melting the 6 port parts when using the header. Maybe that could save you some headaches.

You should post up also in the race car tech section as it gets traffic from a lot of Auto X ers.

Jeff

 

I thought about that problem and tried to solve it with exhaust wrap. The exhaust wrapping was a real pain in the ***, especially if you're using a collected header. However, it worked; the aux-ports never seized. I think the best solution is to have the header ceramic coated. It's a little expensive, but looks great, and you don't have to mess around with fiber glass everywhere.

 

Thank you both for the suggestions. I planned to wrap it or fab some sort of heat sheild, but then I decided to sell the Racing Beat header that I bought and go with a different product that came along. It also allows me to run 3" catalysts which should help with the power.

So I'm in the middle of taking a step back to take two steps forward and I'll post up when I have some progress.

 

I was shocked to discover that the lightest Bride reclining seat setup is heavier than the factory RX-8 seat setup. Hard to believe people pay that much for them, so I gave up on the reclining seat idea. I ended up going with a pair of Kirkey intermediate road race seats. Paid about $910 total tax & all for the pair with padded covers at the local Summit Racing store. They're about 16 - 17 lbs each with the covers installed, but without mounts.

 

Probably a bad idea, but I'm carrying about 15 extra pounds due to my seats. I like them though, and they are comfy.

So it's been a while since I've updated the thread. I've gotten pretty tied up at work and haven't had time to work on the car much. Plus it was very very cold here for a while and I just couldn't be bothered to be in the garage.

I was also waiting on new rear shocks from Ground Control. Those finally arrived and so I started reassembling everything. The fresh front and rear hubs went on. Rebuilt brake calipers. Cleaned-up brake rotors. New Hawk HPS pads. The stainless brake lines. And everything else needed to put the car back on its wheels.

















It took a long time to reassemble the interior. The dash was severely broken in a few areas. I had to reinforce it with fiberglass mat and resin. A bit more of a project than I wanted, but it should hold together.

For a while.



So. Things left to do. The exhaust needs to be made. The ECU needs to go out to Pocketlogger to get the Rtek 2.0 upgrade. I need a front sway bar. I need to tune the car. and I need to figure out why it starts and runs great, but won't idle. Probably a vacuum leak, but I can't figure out where with the thing as deafening as it is. And I need to get my new wheels and tires mounted up.

Almost "done."

 

Great progress John. Nice to finally see some full shots of the car.

 

Looking good John. Let me know if you need any help with that idle issue. I wouldn't mind stopping by to try to trouble shoot it. It's probably just a thermowax issue. I imagine if you let it warm up (after you get an exhaust on it), it would probably idle fine. either that or it's still burning up all that assembly lube and having issues.

what size wheels did you end up going with?

also AWR sells a really nice speedway style front sway bar.

http://www.awrracing.com/store/produ...products_id=83

It's a bit expensive for my pockets, but it looks really nice and is really adjustable. I recently bought a whiteline adjustable front bar that I'm excited about. I have adjustable whiteline bars on my corolla and really like them.

 

The AWR bar won't work with the stock radiator.

I'm going with 17x7.5 wheels. Long story as to why. I found a set of Advan RGs that are 35 offset. Should give me plenty of clearance to the strut and to the fenders.

I'm sure I can get it worked out, but I'm loathe to sit and run the car for long because it's so loud with no exhaust. Hopefully I can get the exhaust welded up within the next couple weeks, once my new header and the cats get here, and then I won't feel too guilty starting and running it. Still, if you want to stop by and check it out I'm sure we can arrange that. Always willing to have fellow gearheads over for a homebrew and car session

The only reason I suspect a vacuum leak is that it idled fine cold when I bought it. It fires right up and goes into its high idle, stays there for three or four seconds, then basically shuts down. If I blip the throttle it stays going just fine. I didn't disassemble the throttle body or anything when I was cleaning things, but it's entirely possible it has a vacuum leak somewhere.

JV

 

Hope the snow hasn't slowed you down too much John. Any progress?

 

Progress has been made but real life (work) took over for a few weeks and I haven't gotten as much done as I wanted. Now I'm out west skiing and won't be back for a week.

My catalytic converters came in, as did the rear muffler. I'm just waiting on my header to be finished and then the whole rig is getting towed to the exhaust shop to get it welded up. I'm going to be using a shortened Rotary Shack header to a 3" metallic spun Magnaflow cat, to a 3" Magnaflow main cat, to a yet-to-be-determined resonator to a large straight-through Magnaflow muffler in the back.

My wheels came in also (a set of rare 17x7.5 Advan RGs in 35mm offset). As soon as I get back the spare N351 ECU I picked up is getting sent to get the Rtek 2.1 treatment. I got a used Innovate wideband O2 sensor and controller off of a friend who used it on her turbo RX-8, and I'll be using that to get a base tune on the car before it hits the dyno.

Hmm... what else to work out. Ground control set me up with 450lb, 6" front springs and 350lb, 7" rears. I'm thinking that I probably don't want to start out that stiff, and the front is a bit low with the 6" springs and the perches all the way up. So probably a better bet is maybe a 400/300 setup, with 7" springs front and rear. Anyone have any thoughts on this? I was going to start with a stock front anti-roll bar and no rear bar, and go stiffer on the front bar if I need to. I really don't know where to start with spring rate.

Oh, and I need to mount the passenger's seat, and put the taillights back in, and replace the fuel filter, and find another A-pillar trim piece and... tons of other stuff. Ugh.

 

The 450/350 combo is a good place to start. I would try it and see how you like it, especially since you are planning to start out on stock sized front bar and no rear bar. I don't auto X my car, I just do open track events, but that spring package will not be rediculously stiff. I run 8k/6k springs which are nearly identical to your spring rates, and it is close to perfect. For me I really could only see going +/- 50lbs either way on either end of the car with DOT tires.

It sounds like you may want a taller spring in front though if you are too low already, or perhaps just a small spacer will do the trick and give you the adjustability you need.

I run RB front and rear sway bars (not sure if you can run these in your class). You will probably need a bigger than stock front sway bar, especially if you plan to run no bar in the rear. As you noted above, the AWR bar is nice, but neds lots of fab work to get installed and working without interference. The Suspension Techniques front sway bar is 2 position adjustable, and the same size as the RB.

With that setup my car is very close to neutral.

 

I'd say the stiffness is probably about right, the stiff front will help reduce camber loss through the travel. I'm going to almost guarantee that the 6" springs will rub under full compression while turning; my 6" 650 lb-in springs up front still scrape the edge of the tire occasionally while turning (I barely have a finger's clearance between the tire and the fender, not sure what yours is).

Also, I have a set of 7" 375 lb eibachs if you would like to borrow them for a test fit up front.

 

With a 225 tire on a 35 offset 7.5" wide wheel I doubt I'll be scraping anything. I have quite a bit of clearance between the fender and the front tire.

I will need to pick up a set of 7's just so I have the option of getting the front end high enough.

What are you running in the rear for a spring and what bars?

 

*shrug* My front end must be a bit saggier. I had to pull fender liners, the little plastic guard on near the rear control arm bushing (would rub at full lock), and even then my 225/50/16s on 16x8 +30 JUST cleared the spring perch.


I'm running 650/500 with stock bars, camber: -3*/-1.8 and a 1/16 toe out up front. When I was still on the 225 RE01s, I had a 375/275 (came with the used kit i purchased) with the same alignment. Both setups have seemed pretty neutral to me, but man does the stiffer setup slalom better (as well as being better practice for the CSP car I'm doing national stuff in this year). When I first bumped the springs I thought I'd have to pull the rear bar, but I haven't had enough of a complaint do disconnect it yet (having run probably 8-10 events on it). FWIW I'm hardly the best driver out there so take all the above with a grain of salt.

 

My 17x8s with 225/45s are amazingly close to my spring perch but don't rub (probably because of less tire bulge/movement) I'm not sure what my spring length is though. but my perch is right where the rim lip is. the 7.5" wheels will probably pull the tire in a bit more and make it better.

a 7" spring will bring the spring closer to the tire than a 6" spring would be... it might be better to make some sort of spacer that is smaller than the spring would be if you end up having fitment issues. But I don't have much experience with 16s.

But let me know, because I'm planning on putting my stock wheels back on soon with some 225 star specs for the street and was planning on just getting a 5mm spacer, but it seems I might have to go bigger.

 

I think alot of it was how wide the RE01s were. Actually, now that I think about it, the Azenis had the same issue when I ran them. My 710s, which in theory should be the same width as the RE01s (both 225s), have much more clearance between the sidewall and the spring. To give you an idea of how close it was, when I had the street tires on, I couldn't run my 16x8 +32 pair in the front because they actually rubbed the spring. That set fits fine up front when shod with the 710s

edit: SoloM, disregard my length advice, it seems like you have much more range of adjustment on your kit. Mine has maybe 3" total up front, which probably explains why mine is so low by comparison.

 

this is an awesome thread, can't wait to see more updates.

 

I'm trying to figure out why going to a 7" spring would cause more of an issue with tire clearance. The spring perch is about the same diameter as the spring itself and the perch is at the same level as the sidewall as it is. I think it's very likely I will end up with a 5mm spacer up front.

 

the spring is slanted out towards the hub... So if it's longer that means it'll go down closer to the hub and closer to the wheel at the same time and also moving the perch down and closer to the wheel.

Again I don't have experience with 16s so I don't know where the spring and perch will be in relation to the wheel and tire so it's possible it might not have any negative effects at all.

 

7" springs shouldn't be a problem, especially if you wanted to raise the car about an inch, the adjusters wouldn't move in that case.

450/350 is really in the ballpark, i dunno about auto-x specifically but if anything its a little stiff in the rear, but then you're taking out the rear sway bar too.

anyways its close enough, that you can run it and worry about everything else first

 

Excuse my ignorance here, but please explain running no rear bar? Would you be taking it out to prevent oversteer due to your stiffer suspension?

I left the stock front bar and installed a larger(Suspension Techniques) rear bar to cause more oversteer. I bought it because I felt like I was having a lot of understeer at AutoX.

I run some used Tokico Illumina's w/ GC coilovers, Don't know the spring rates on them. I also have not gotten an alignment since I put them on, I just cranked the fronts as far and evenly inward as I could for the first AutoX I ran with them and it seemd to work.
I run either old Kumho Ecsta Supra 712's on stock wheels or 225/50/15 Kumho V710's on mustang wheels depending on events.

I improved my times with ny New-used setup at the end of the season. I also Drove Eage8's car and it felt like it understeered like crazy.



I know I need to do a lot of reading on suspension tuning, sorry to threadjack here.

 

If I end up needing the rear bar I can put the stock one back on. In general though, for a car with a sloppy diff (like the viscous in the GTUs) I want a very small rear bar or none at all. It helps mitigate the car's desire to light up the inside tire exiting corners.

I may start with the bar installed and then remove it later.

 

^Yup, I removed mine just to make throttling out of corners a little less spectacular

 

after I softened up my front dampers at your house after that it got a lot better. I was trying to solve my total lack of rear traction the wrong way and just ended up making my car unpredictable...

a lot of what you thought was massive understeer might have just been you being used to the v710s and my car being on street tires so you were just carrying too much speed. My car definitely doesn't feel as balanced as yours did though. I'd like to drive them back to back again after I finish up with my suspension work over the winter.

 

the thinking is that removing the rear bar lets the suspension act more independent.

compensate for this by running a stiffer spring in the rear.

both approaches are valid, it depends on the course and the drivers style/preference