Franken44 Track Build

Now that I have the car built, and a little more time, I thought I'd put up my own thread on the car, and some on-track video. (apologies to Lemming on the derivative name - Franken44). The car is built to NASA ST rules - ST2/3 depending on tune & ballast

The Specs:

-1987 944 Turbo chassis
-2004 GTO motor - stock internals, lightly worked 241 heads, flipped intake with cowl induction. TPC short tube headers. 350HP/362TQ at the wheels.
-Wilwood 6 piston calipers (used from Ebay) front, OEM turbo rear
-Tilton Triple Pedal floor mount pedals
-AOR trans with custom oil cooler
-JRZ triple adjustable coilovers (bought used)
-Hyperco springs 800F/900R
-Hanksville Hotrods cage with custom extensions to shock towers
-AIM data system

Before the aero: [You must be registered and logged in to see this image.]

Rearset triple pedal setup - moves me back in the car - better weight distribution, easier egress with halo seat, and easy installation of MC's.m (Edit: this picture is cut off, will work on getting a bette one up).

[You must be registered and logged in to see this image.]

Handy place for MC reservoirs; [You must be registered and logged in to see this image.]

Extended wheel, smoked lexan dash, and rearset shifter to help me rear the controls from back there!

[You must be registered and logged in to see this image.]

3/8's plate steel caliper adaptors (tight fit on the bolts, but workable, and the spacing works out well)
[You must be registered and logged in to see this image.]

Massive Wilwood pads!
[You must be registered and logged in to see this image.]

Some video from Road America below - 1st event with aero. Ran a 2:26.3 in ST3 trim (ballasted to 3,000lbs, detuned to about 340 HP, and with little 245 Hoosiers). 996/7 Cup cars were running around 2:22 that day. This was 4 seconds under the ST3 LR. Not bad, and more development to come. Lap #3 is the 2:26.

[You must be registered and logged in to see this link.]

A little excitement in the kink at Road America:

[You must be registered and logged in to see this link.]

More to come, but I can't get to all the pics from my work computer. Plan is to run NASA Championships in ST2 (that is where the cars are at) - so around 2,800 lbs, unrestricted output, and bigger tires.

I will say it's been great fun, and and very reliable so far!

Hey Eric,
nice lookin car, dude. Good luck at Nationals, I assume you're going to east coast at VIR?
ST2, man, watch out for those vettes.

phlip wrote:Hey Eric,
nice lookin car, dude. Good luck at Nationals, I assume you're going to east coast at VIR?
ST2, man, watch out for those vettes.  

Yes, going to the East Coast Nationals. I know the C5 Mafia has very well developed cars, and I have a lot to learn, but people like Jim Stevens have shown there is good potential in the 944 chassis. This will still be a learning year, but hopefully, I can be reasonably competitive along the way. .

Looking good!

Nice times. And good to see another rear-set driving position. Please share details on your aero, that's what I'm planning next.

Rich

Sick build, I bet its a blast on the track... I had issue watching the videos though. Video links are broke for me...

What kind of wheel/tire setup are you running. How much of a handful is the car in your opinion?

Digging the MC setup...and I may end up going that route with my build before its all said and done. Was planning to try the Hydroboost setup first though.

Fixed the video links, thanks!

4 free tires from Hoosier for the two wins at Road America (girls not included)

[You must be registered and logged in to see this image.]

No issues with Franken44!

Aero is definitely your friend on these cars, especially at a place like Mid-O.  I would love to find a decent rear diffuser that doesn't cost an arm and a leg 

It looks like Jim Stevens is working on a full aero package for his car here:

[You must be registered and logged in to see this link.]

Working on putting the car on a diet to make ST2 weight at Nationals today.

How would you route the exhaust with a diffuser? I am thinking of adapting a "Boom Tube" setup like this:

[You must be registered and logged in to see this image.]

Just got back from NASA's Eastern Coast Championships. We finished second, but in large part to outlasting the competition. I struggled with learning VIR, and car setup all at the same time, but am pretty happy with how things came out in the end. I had a great race with Dave Ballingit in his tube frame Monte Carlo, and managed to stay ahead. I learned a lot about what it takes to compete on this level. The biggest takeaway was to find a way to fit really wide Hooiser A compounds. With enough width, you can get the soft compound to live, and it's worth several seconds to do so.

[You must be registered and logged in to see this image.]

I've known Dave for the last ten years, been one of his instructors since '05.

I rebuilt the calipers on his race car earlier this season, sorry to have contributed to your loss!

It certainly does seem like unless you're on "A"s you're giving up a lot...

Nice job Eric, sounds like its time to go wide body fenders ans quarters.

Congrats Eric. When you say wide, how wide?

Sorry, been away for a while. The 'Vettes were running 315/345 F/R, the Lotus Elise (2,200lbs) had 245/275 F/R. I can just fit BFG's "cheater wide" 275's under the stock fenders. Mayne a 285 Hoosier.

So after struggling a bit to get the brakes dialed in this year, I have finally found the holy grail of manual brake setups.

Most important was switching the the Wilwood Polymatrix "A" compound front brake pads on the Integra 6 calipers. I had previously used the H compound for it's good high temp friction, but I must not get the brakes that hot. Pedal effort was high, and initial brake bite was poor if the brakes cooled at all. So I'd have this weird sensation of little brakes intially, and then more and more as I got deep into a high speed brake zone (like turn 5 at Road America). Very disconcerting, and I was giving up a lot in the braking zones for a comfort margin. The wear was amazingly little through 15 track days though:

[You must be registered and logged in to see this image.]

The Polymatrix A pads have much better bite when cooler, however:

[You must be registered and logged in to see this image.]

This turned out to be very noticable - pedal effort was way down, and no weird ramp up under heavy braking. Much better initial "bite" and better modulation. They are a very aggressive pad - noisy, and abrasive, but work extremely well.

The second mod was to put the stock rear Brembos back in place. The previous front Brembos in the rear had too much piston area - required a large MC to make the bias work, and this resulted in very little piston travel, and difficult modulation of the rear. Moving back to the OE rear brake setup balanced the Integras better. I run Hawk DTC - 60 pad in the rear. I might try a DTC-70 for even a bit more bite, but that may be one step too far.

Master Cylinder sizes worked out to be .75 F & R for the Tilton triple pedal.

So the last event at Autobahn, I could finally stop with confidence, but I had a RF shock blow out, making for a bit of a bucking ride. The track was also drying during this session, but I was able to hang onto the leader for a bit, and even with the Super Unlimiteds. I had to be very tentative around other cars, because the front end would oscillate out a couple of feet at a time over bumps. *New front shocks are coming from Olsen Motorsports, as I found the old shock bodies had cracked at the weld for the spindle mount. :eek:

Video here:

[You must be registered and logged in to see this link.]

We are very close on brake setup, I've been running the Integra's with stock rear brembo's for awhile now.  I had been running DTC70's front and 60's rear, but two events ago put on the polymatrix A's (which I like a bit better than the 70's).  My mc's are 0.625 front and 0.75 rear.  

I'm still trying to get a set of two piece rotors built, but there is very little room between the hat and calipers in this setup.  Spec is looking into bolting the rotor to the hat from behind.  Should hear soon if this is possible or not and will let everyone know.

By the way, when I pulled my DTC 70's from the front, I measured the pad thickness and only burned up 3mm after being on the car for more than a year.  Not bad!

Interesting we wound up in the same spot independantly. Great minds...

Hope we meet out on the track some day!

Sterling Doc wrote:Interesting we wound up in the same spot independantly. Great minds...

Hope we meet out on the track some day!

Two upcoming races at Barber, Nasa-MidSouth the last weekend in October and PBOC in late November. The latter is my favorite race of the year, great weather and great group to race with.

I think I'm done for the year to lick my wounds after having to replace the front JRZ's. Maybe next year!

A few updates - been a long time!

A new custom cam went in to make real ST2 power if needed, along with a restrictor plate if I'm running in ST3. Dyno runs to come soon as everything is just back together now. The front JRZ's have been re-done.

I am deep in off-season aero research and development:

The Turbo Miata forums are a wealth of info on budget aero:

[You must be registered and logged in to see this link.]

This bit of CFD aero analysis prompted me to look into and "EP" style nose for the Franken44:

[You must be registered and logged in to see this link.]

[You must be registered and logged in to see this image.]

I can seal in and route the ducting much better with this arrangement. I still have to reinstall the upper radiator shroud (exposed now).
I also plan on making the lower lip height adjustable by cutting off the lower 2" or so, and slotting the attachment points, to make the splitter height adjustments easier.

I have also adapted a "boom tube" style exhaust (another ex-Nascar Ebay part), to keep exhaust heat away from the trans, CV joints, and gas tank, which had been causing some issues.

[You must be registered and logged in to see this image.]

This is flat enough to allow a flat bottom, without having to take the penalty in NASA ST for a through the body exhaust. Lots of heat management required - it will be wrapped, and high temp heat reflective material used, as the exhaust will now be in an enclosed space.

I also had to re-route fuel line to keep it away from the exhaust - always a cascade of implications to one change on a racecar!

Thought of the same exhaust set-up. Nice work.

Great results last year as well.

On the subject of tire width...

285's will fit all four on a stock chassis with the right offsets

Broadfoot flares will fit 295's front and 335's rear but it's tight.

My new XP racer will be wearing 335's on all four, unless I elect a bias ply option (which will be wider).

Hope this helps, enjoy your off season!

Last year I had "cheater wide" BFG's in a "275" size, that just fit with rolling the fenders. They are wider than Hoosier 285's by jut a bit. In NASA ST, the break points for tire sizes are 245, and 275, so taking the penalty to go to ">275" with for just a 285 "nominal size" tire isn't worth it. When I class down to ST3, I will run Hoosier 245's which also run wide in that size. Tire managment becomes very important in the samller sizes, but they can still be fast.

Video from startup with the new cam and exhaust: [You must be registered and logged in to see this link.]

I real many of the same aero articles when putting mine together.  I didn't want to build anything, so I went with the broadfoot front end which is close to what you have.  I opted not to add brake venting to the  front fascia, but instead put them in the header panel.  This increased brake cooling significantly.  Please post picks of the flat bottom setup when you start.

Flat Bottom installation:

Got a piece of 8'x12' 6060 T6 11 gauge aluminum from a local trailer dealer (they gave me their whole price from  the distributor).

[You must be registered and logged in to see this image.]

Built a framework below the oval/low profile exhaust
I took off the factory jacking nubs, and used the threaded holes a s a central hardpoint to mount the dropped floor from.
[You must be registered and logged in to see this image.]

Made a cardboard template of the floor:
[You must be registered and logged in to see this image.]

Completed flat floor from front to back. It's about a 3 inch ride height, rising to about 11 inches at the tail end of the diffuser. I still need to make vertical vanes, but it is coming along!
[You must be registered and logged in to see this image.]

As she sits now with the hood and fender vents added as well
[You must be registered and logged in to see this image.]

It going to be hard to wait the week until the first event at the National Corvette Museum!

Looks awesome! Thanks for sharing. Mine is coming along, working on a proper splitter and plan to do some type of rear undertray. But I have the stock trans cooler so can't cover that entire area like you did.

Best of luck with her debut!