DaveTurnerMotorsports

We've done very limited testing with the new '89 GTUs, but have gotten it down to 2500lbs and still keeping all of the stock interior including seats and 2+2.

Suspension is set with custom Bilsteins in AWR front strut housings (Porsche 914-6 shocks in rear with AWR upper mounts), Eibach front sway bar, 400# front and 325# rear with no sway bar, AWR custom lightweight upper strut tower bar, Corksport rear upper strut tower bar, Mazdaspeed lower arm bar.

We've been running on 225/45-16 Hankook R-S2/Z212 street tires at full tread on the stock 16x7" wheels, scheduled to arrive tomorrow are 16x7.5" Kosei K1's from TireRack. Need to play with spacers as the stock wheels are +40mm offset and the new ones are 1/2" wider and +42mm offset, we're already running 10mm spacer up front and 5mm rear.

Camber is set with plates and crash bolts to ~-3.5 deg front and ~-2.25 rear, castor nearly 5 deg both sides.

We were having brake lockup issues with the Hawk HP+ pads, wend back to the stock Mazda pads in the front and kept the HP+ in the rear, with limited experience we get a little too much trailbraking exaggeration...may go back to Hawk HPS all around for contingency $$.

We started with a fresh stock-rebuilt engine (S5) that ended up only showing 79hp to the wheels when we discovered that the butterflies were not opening in the intake manifold, and the A/F ratio was falling to nearly 6:1 (rich!!!). Fixed the problem, still running 10.5:1-11.5:1 A/F (still very rich) and with a modified Racing Beat header, stock-replacement cats x2, and a singe exhaust only showing ~109hp. The engine is far from being broken in, and the car is running VERY rich above 5800rpm, probably the culprit of the power loss. Another stock '91 convertible on the same dyno (Dyno Dynamics, inherently reads on the low side) with a little smoke and original high-mileage motor put out 113hp, all-stock exhaust system and cats, but with good A/F ratio throughout.

Car is running better and better, and with most/all of the Top STS and STX drivers to compare to, we went from running 4-7 seconds back (79hp) to now less than 2 seconds back after only putting 10 laps on the car and current setup.

Any suggestions? The car feels good on the current setup, but I would like a little more initial bite up front. Some on-throttle oversteer after initial understeer, but very controllable and smooth overall and much quicker than we have ever been up to this point. We are now beating the Miata's in Cal Club Region (los angeles), but our other clas regulars in San Diego Region were no-shows.

Any help or good suggestions would be appreciated, I don't like to venture into the unknown without some educated guesses and bench racing to go with it. We used the Mazdaspeed setup guide for ITS as a start, and with very smooth courses expected at Nationals this year, many many street tire class cars are running surprisingly stiff setups even to the point of being beyond what many IT cars are running (Honda's running 700-1500lb rear spring rates in some cases, Miatas estimating nearly SpecMiata rates of 700/450 on street tires!).

-JW

Travis R

I like that you don't run a rear sway bar, hopefully your front bar is adjustable so you can make quick changes at the event.
Obviously getting the fuel dialed in will help... that's about my only suggestion.
I mentioned your project to Andy Hollis and he thought an FC could be competitive in STS2, given the power available and the better tire sizes compared to the miata.
Good luck!

DaveTurnerMotorsports

Hopefully Andy will get this Miata finished up and ready for the Tour, it would be great to get in on some good STS2 action....its tough trying to compare the class to STS when they've had many years to properly setup and learn the nuances of the Civics, not so really for the STS2 cars other than "start with CSP settings and back off from there".

I think with so little time remaining, we will finish up the proper quiet exhaust for the Tour and try to lean the motor out with an add-on piggyback, as it is the only legal way to do so (we could go mechanical, but that removes the possibility of reworking the ECU/EPROM in the future.

The wheels came in today, we'll see if the 'kooks like a 1/2" wider wheel on a 225.

-JW

Black91n/a

You could always try various degrees of toe out at an event to get better turn in response and possibly more initial front end grip. You should be able to fairly easily change your front toe settings at the event. Maybe some 350lb springs in the rear for more oversteer, or a stock rear bar would also help give you more oversteer, but you probably want to keep it off of the car for now, so you're stuck with adjusting the front bar for fine tuning. You should check your 6ports and VDI for proper operation, that can cause a power loss.

Also, be sure to run with the windows down for a lower CG ;-).

MPM

Is it legel to run and adjustable fuel pressure regulator? Some of the ITS guys run that and it really makes a difference.

finky

iTrader: (2)

Would it help your brake lock up problem to run less frt. camber(3.5 seems high)and more caster?

Also, if anyone wants to do a Pro Solo this year you better preregister. I heard that the DC Pro is filled and the Arkansas one was close.

DaveTurnerMotorsports

STS2 is limited to 225 tire width and 7.5" of wheel on a true street tire, so there is no possibility to reduce the negative camber-- it is absolutely necessary to make the car work. The GTUs has the TII 4-piston calipers (no ABS), and with the street tires any kind of performance pad was overkill and caused lockup....so back down to stock pads we went.

We can run a FPR or ecu controls (within other rule guidelines), but not both. The SAFC is probably the way to go, and it will be installed and run on the dyno next week before the San Diego National Tour and Fontana ProSolo the following weekend. Always pre-register, both filled up fast this year! We are also planning on the Atwater Pro/Tour, Houston Tour/Mineral Wells Pro (in-laws live in Austin, they want to come up/down for the races), Denver Pro/Tour, and Wendover ProSolo.

New custom exhaust goes on this week, last weekend we were up to 96dB on the sound meter, so longer Magnaflow and dual resonators + two stock cats and short-primary header should quiet things down to reasonable. San Diego is a tough spot as Qualcomm Stadium (Chargers, ex-Padres) is smack in the middle of a residential area. Funny, they run Drift and 1/8-mile drag down there and they don't have sound restrictions, just the autocrossers :-)

New seats are going in this week in another effort to reduce weight legally, Cobra Imola GT (kevlar) on the driver's side....26lbs with aluminum side mounts and heavy steel bracket, and Corbeau Baja SS seat on the passenger side (15lbs plus brackets, soft n' comfy for those codrive road trips but lightweight and stupid-cheap, class rules have seatback height requirements and minimum weights...fits the bill nicely).

-JW

DaveTurnerMotorsports

Car is almost ready, test-n-tune for the San Diego National Tour is tomorrow.....wish us luck! Results and other info can be found at www.scca.com, click on Solo, then National Tour, then San Diego.

-JW

DamonB

^ Give 'em hell!

TwoFun

here are my thoughts:

3.5 neg camber seems high to me too, use proper tire temp probe to find out if you need that much camber.

Abit less front camber should help your turn in, and less toe-in the back for your "power oversteer" preference.

front toe should be zero.

try put stock rear bar back to help understeer(if you need it) as long as it does not have neg-effect on putting power down.

oh yes I do have a 89 GTUs thank you very much. keep up the good work, like Damon said, go get them!

keep us update on your progress and feedbacks!

Travis R

Did I see the results right...your codriver win STS2? Congrats! Hollis was right behind him after day 2.
Good job!

DamonB

^ Looks like the car went fast!

DaveTurnerMotorsports

http://www.scca.com/News/News.asp?Ref=527

Keith Casey came out from MA to help me sort out the car, handling with the current setup is nothing short of phenominal, but may still require a few minor tweaks in shock valving to be perfect.

Keith led both days of competition with the fastest raw times, about 0.8 of a lead built over the Miatas on Falkens. I had been closely behind Andy Hollis (0.3 sec) for 3rd place, but coned away each run to finish just 0.2 sec out of 3rd place with my cone penalties!

The car did start to deteriorate on Sunday, as the new header melted the innerds of the 6-port acutators and basically killed the power on the motor. Nevertheless, Keith managed quick raw time of the day. Our last laps were SO BAD that the car just wouldn't rev past about 5800rpm, as the 6ports weren't opening AND we still never leaned the motor out past 10:1 A/F, so the fuel dump didn't help things. The car would just shudder and pop and not accellerate. Making the 18 mile drive home from the Tour was brutal, the ports would stick on the rear and chug and pop, especially at stoplights.

Back in the shop to fix before the ProSolo in Fontana to back up our first RX-7 win ever in Street Touring history (ha ha), not to mention in a 500lb overweight car with "inferior" tires (Hankook, unshaved) and non-adjustable shocks (Bilsteins)!

-JW

Travis R

Don't slack off on developing the car, you know Andy won't.
Any pictures of the car in action? It looks like you've updated your avatar.

Black91n/a

SWEET! Your car beet Andy Hollis' Miata. Congrats! Have you seen his buildup online? It's on the GRM site, and he's sunk some serious money into building that car. He's got a complete engine build to the limit of the rules and he's running super expensive, super trick Koni 2812's!

Keep up the good work and stick it to those pesky Miata's!

Imp

Hey, lookie what I found!

James.. you get the car fixed yet? Can't wait to watch this weekends results.

--Keith Casey
(P.S. don't forget to wrap the header)

DaveTurnerMotorsports

Replaced the fuel pump wiring, fuel pump, rear 6-port pot, added a heatshield for the 6-port system, and discovered the trailing ignition system is non-functional. No wonder the car crapped out on Sunday. I'm really surprised we even finished.

Hopefully we can get it sorted out today before the WET and COLD ProSolo in Fontana!

-JW

DaveTurnerMotorsports

Another Press Release from Hankook Tires USA. I don't recall seeing Jeff Kiesel's wife running Hankooks, though :-)

http://www.hankooktireusa.com/press_view.asp?ID=92

Black91n/a

I saw in a thread on the miata board that Hankook's coming out with a 225/45/15 int he RS2 Z212. That would be a really good size to run. Maybe you can get them to donate a set (or several) to you now that you're making them look good.

DaveTurnerMotorsports

What, and spend money on a new set of 15x7.5"? I think SSR has the only good ones that will fit the FC, and that is $$$$$$$$$$$$$$$$$$$$$$$$$$.

I'll take my $150 Kosei 16x7.5, thank you very much :-)

Forget it :-)

Black91n/a

Just a suggestion, if it was me I'd keep the 16's too, less money that way.

TwoFun

how is your suspension set up work for you? any future change in term of spring rates? alignments?

enjoy!!!!

DaveTurnerMotorsports

Planning on a slight tweaking of the shock valving, close work with Bilstein shortly. Front rates going down to 392lbs from 400 (!!), but losing 2.5lbs per spring in dead weight.

We'll let you know how this setup works in the wet at the Pro this weekend.

FWIW, the car won STS2 in San Diego on 68hp...........we're now up to 97hp and 100ft-lb as of the end of Friday's session.

finky

iTrader: (2)

I heard an unofficial result that James won the STS2 class at the Pro. Good Job. I am going to search for a viscous dif now so that I can run in STS2.

DaveTurnerMotorsports

I resemble that comment.......yes, the RX-7 won the ProSolo at Fontana and I happened to be driving it this time. We are 2-for-2 in California at National races, I am now looking for a good used (read: cheap) SAFC so we can get the car running correctly. My sub 0.580 lights helped a lot, but the 2.7 60' hurt waaaay too much.

Thanks for being interested :-)

-JW