To serious road racers in the group. I am setting up an FC for NASA Super Unlimited in Nor Cal. some questions;
what oil temps do you see, and what coolers are you using?
spring rates?
dampers?
special tricks in lightening the car?
tire, wheel combo?
brake pads?
stock calipers?
rotors?
Any comments appreciated.
My "starting point is an fc with a 3rd gen motor, street port, to4s, e6k, entry level Ground control coil overs with 375lb front, 325lb rear springs, gutted.
On the way new harnesses, Kirk weld in cage,installing new gauges.
Need seats, suggestions?
TIA Carl Byck

 

most guys are running seem to be running 500lb or 550lb fronts and either 300 or 350lb rears depending on how tight or open the track is

 

i think the main way everyone lightens their car is to take out everything they dont need.
interior heating ac powersteering emissions sound deadner.
another way i could think of lightening the car is to get fiberglass parts ie bumpers fenders hood..

if this is going to be a track only car you could remove the inside bumper kinda thing. and cut its supports.
im not sure on that though.

 

Well, oil temps is going to be different for you running a T2 vs NA. With my old Griffin setup, I was running 180 water, 210 oil in 95* weather, no fan at Thunderhill.

Spring Rates: 400/275, going to 500/275 soon, experimenting.

Dampners: Koni SA struts

Lightening: Well, SU means the sky's the limit for you. Lexan front/rear windows, no interior door panels (or Carbon Fiber/Fiberglas replacements, fiberglass front clip, and liberal application of the hole saw to the doubled sheet metal panels inside. Obviously, no dash, aluminum seat, no insulation/sound deadening.. All smog removed, all unnecessary parts removed from the engine bay.

Tire/Wheel: I'm restricted to 15x7 with Toyo Proxes RA-1s. Running SU, you can run 16 or 17s, I'd probably go with 16x8 unless/until you get flared fenders, then 16x10s running Hoosiers.

Brakes: SU allows you to upgrade those, but if you're staying wtih stock for now, I run Carbotech panther plus pads with stock rotors. They work fine with my RX-7

You are aware the Kirk cage is not legal for NASA or SCCA racing without modifications?

Coil overs are great, but what struts? Your spring rates are way too soft for road racing, especially in the heavier T2..

seats, I like my Kirkey Intermediate but then that's about all I fit into right now. The kirkey road racing seat is reputed to kick ***, but at 600 bucks, it had better. Otherwise, Sparco/Corbeau/Recaro all make good seats, you just need to find one you like.
Frey Racing in Milpitas has a great selection of seats to try out.

PaulC

 

Kinda off the subject, but Silkworm seems to have all the good info. I am also planning on putting my FC on the track but don't think It will be competative in SU. What are the basic guidelines for an EP car. I talk to a guy at Sears Point who was working with SCCA and he races an ITS FC in SU and say's he does real good, 2nd and 3rds. Basically mines an ITS car with 4port bridgeport, and a Holley 650. Which class would I be best suited for.

 

Bridgeport is too far for E production, Street port is all you can do there. No bridge port, no peripheral port, no modification of water jackets (no eyelash port??) T2 components not allowed.

You're in GT2 category with the bridgeport, not sure if using the 4 port engine is allowed there either.

You could run SU (which is a NASA class), or ITE (SCCA). In ITE, you could be competitive, but SU has some very wicked stuff show up sometimes, so no guarantees there.

PaulC

 

EP 2nd gen is 13b streetport with 2bbl carb 38mm venturis or EFI with a weight penalty, making an already heavy car heavier. No bridgeport. Suspension is qute liberal, u can relocate, add, and remove suspension pickup points. Brakes are stock size rotors if I remember right and u can use Tilton masters. Fiberglass fenders, airdam, nose with a front airdam and no rear wing. Gutting and thorough roll cage required.

Here's a link to Mariah's extremely competetive 2gen EP. I anticipate this car taking a top 5 finish at the Runoffs next year.
http://www.fc3s.org/track_time/butto...th_mariah.html

4 port Bridge 12a would move you to SCCA GT3. 13b bridge is GT2. Can't use a 4bbl with that motor and class. 2bbl or EFI with some sort of weight penalty.

Or you can do just about anything in Super Production, including having ur a$$ handed to you by the big dollar guys.

http://calclub.com/reg_rules/s_p.pdf

Best of luck!
-bp-

 

KYB AGX shocks/struts are budget oriented but good for the price $355 for all 4 corners. 4 way adjustable up front and 8 way out back. However you can only run a 400-425lb spring max on them up front.

I run K2RD.com coilovers with these shocks on my "street car" and would like to roadrace the car one day when I finally get an oil cooler installed. I have 400/250 spring rates and love them on the street (I don't mind a firm setup).

However as noted you want stiffer spring rates up front for sure and out back may be about right. Call Mariah Motorsports, Racing Beat, TriPoint Engineering and ask them for recommendations on setup. Koni's are the sh*t though and if you have the $$$ get them.

TriPoint Engineering makes a widebody kit following the stock body lines of the FC. $1K for all 4 pieces and it allows 275's up front and 315's out back with the use of pricey custom rims.

Mariah Motorsports offers flared front fenders that allow 255/17's all the way around and if you had a custom offset rim like (SoulAssassin) he fit a 275/17 out back. Rims nonetheless will cost you the $$$'s in the end.
FD rims fit out back with no prob's on a FC 16x8 and allow 246/16's or maybe even larger 255's etc. FD rims up front require hubcentric ($150 to $180+/pair) spacers but with the abovementioned flared fenders maybe you can run a 245/16 up front and that would be a budget way to get you started.

The rear hatch weighs a ton... keep the outer frame, break out the glass, and make the center out of lexan and aluminum for bracing. Gut the interior and the sounddeadenging/tar from the floor. Dash... bye bye and all HVAC related stuff (a/c, blower fan, vents/piping). Front/Rear bumper supports are 20lbs each I think. Maybe remove them and make a replacement out of aluminum if it is legal.

Stock brakes may work.... however contact K2RD.com about their solutions or CorkSport Racing in OR about their AP RAcing 13" or 14" racing setups. $3200+ to start for the front brakes alone!

Gotta pay to play as the old adage goes.

Maybe in a year I'll have a car ready for the NASA unlimited class as well. V8 widebody FC at 2500lbs and 500hp naturally aspirated...... .

Good luck with your project and keep us posted.

I have a few used T2 diffs should you need one down the line in the event of a failure.

-GNX7

 

I think it was ITE that he was talking about. It was the IT that threw me off a bit, knowing alot about the ITC and ITS rules. I thought big porting was not allowed in IT racing just a street port.?
GNX7, why do you want to roadrace a V8 RX7, it would not handle that good, look at D's car!! Let me or Ho build you a motor, well probably me due to Ho's hourly figure he'll want. Just by the parts. You got the turbo, intercooler already. I could try to keep up in the N/A.

 

ITE is a catch all class, but it's regional, it depends on the region's definition of ITE. Here in SFR, it's run what you brung, on DOT tires. My buddy Alan runs a 94 Z28, fullblown aeropackage, 355 putting out ~420HP that has run just shy of 200MPH at the Nevada Open road races, but he's having trouble with a guy in a turbo 300ZX who is currently leading the points race (And I think just won the championship for ITE).

In some regions, ITE is definied as a catch all, AS LONG AS your car meets rules for a particular racing series.

It just depends.

PauLC

 

SPZ510-

13B is nice...... but show me one with 1/2 the torque of a V8 and that is the reason why I am a big fan of engine swaps. Torque wins..... and the unlimited class would favor this type of swap.

Upgraded suspension in a widebody FC with some good stickies with LS1 or LT1 would make the car a killer at the track. 400rwhp 2500lb FC N/A is easy with a heads/cam stock shortblock LS1. 430rwhp has been achieved by one guy with a heads/cam stock LS1 shortblock.... but that is a freak car IMO.

-GNX7

 

I'll see you one dyno pull and raise you a pink slip. My 13 bt makes 430rwhp, and 360 ftlbs of torque. the car weighs around 2450 plus driver. All this on low boost(14psi) I suppose I could add some 100 octane, turn up the boost to say 18-20psi and lay waste to your v8 monstrosity. No flame really, but this is the RX7 forum, not the kit car forum. Don't misunderstand, I like pistons too. I have a fourth gen Supra that makes 420rwhp with a couple of bolt ons. That motor can make 700+rwhp w/bolt ons for around the same money it took to make 400+ in the RX7. however at 3600lbs it needs that power to keep up. I think the point is trying to stay with the rotary and make it better, not replace it. In the end, to each his own. peace, and best regards, Carl Byck

 

only 360lb-ft?

 

SPZ510,

NO porting is allowed in ITA/B/C/D/S.

ITE you better have porting or you're a back marker. In L.A., last year's ITE winner was a 3rd gen with 13b peripheral port 48 IDA and very good driving and setup. ITE costs a lot of $ to win and not much $ to be a chump.

GNX7, I commend your craftsmanship and time putting a V8 in a Rx7, but piston's don't belong in a 7, let alone on this message board. That's an abomination! You shoulda bought a Camaro.

My little 250hp 2100lb 12a bridgeport 1st gen with great gearing does quite well at the track! I've passed 3rd gens and LT1 Vettes!

-bp-

 

God, do we have to do this on every forum on this board? It's an RX-7 forum, not a 13B or 12A forum. GNX7's car is a masterpiece, it DOESN'T have a V8 (sheesh, as if GNX wasn't a big enough clue as to what is in it), and this particular forum is about race car tech, not engine wars.

BP, I have video of my poor little 13B stock port 2680lb porker passing LT1 vette, S2000s and WRXs, big whoop. Anyone on this forum should already know that it's driver's skill, not horsepower that rules the roost.

That sure is a pretty 3rd gen running in Cal Club ITE.. Gorgeous more like it.

PaulC

 

Huh, I thought the ITS rotories were all streetported. That makes me feel even better, cause I saw an ITS RX7, white with light blue/blue splash paint on it, keep up with that lime green and red RSR Porsche at ThunderHill. The description is for the locals who might know the peticular cars I'm talking about. The 7 kept up on the straights and passed the Porsche easily in the corners. Correct me if I'm wrong but aren't those RSR's like $200K. Damn, if my car which is basically a ITS car with a bridgeported 4port, can smoke a Porsche that someone blew $200k on, I'll be so happy I'll poop. . All I need now is a full cage and K2RD's coilover package with AGX's. Can't wait!!! Any help with setup I can get from you guys that run on the track will be much appreciated. Tires? Pads? Swaybars? what do you rec.
Also, what class might I have been watching with these two cars in it? This was a NASA event. Thanks

 

re:"ITE you better have porting or you're a back marker. In L.A., last year's ITE winner was a 3rd gen with 13b peripheral port 48 IDA and very good driving and setup. ITE costs a lot of $ to win and not much $ to be a chump. "
At this point I'm just aspiring to be "The" Chump .

 

Put simply, no it won't.

A properly driven RX7 is honestly no match for a properly driven RSR. Plain and simple. In my years of instructing with PCA DEs, I have formulated one overriding opinion:

"Just because they can afford it, doesn't mean they have the talent to drive it."

Keep that in mind the next time some rich guy shows up with an ultra-expensive Porsche, Ferrari, etc.

 

Man, you need to get tims in here - he's running NASA SU in his FC turbo.


-Ted

 

How true!

ESPECIALLY the 911's. You either are REALLY confident in your driving ability or you never take it over about 7-8/10ths in the corners. I remember only one 911 driver who was confident enough to wring the most out of his car, his car left the track on a trailer and it looked totalled to my eyes.

That's why 911's are fun to play with. Technically speaking they are faster, but the driver plays an even bigger role than most cars.

 

Having worked at a racing school over a year for Star Mazdas and street cars, I've seen every type of driver with every type of car. Basically the faster the car they arrive in, the worse on the track they are. However the guys showing up in these super cars are "older" and less brave than the young bucks, especially the kids wtih daddy's checkbook.

 

911's or any rear engine car for that matter is all about controlling trailing throttle oversteer. That means no lifting in the turns or the rear will come around, espacially if the car is being pushed. There is a reason why the engine is out back in "real" race cars i.e. formula cars, and that is beacause they are more sensitive to driver input, which translates into faster laptimes with a competent driver.

 

How bout a 20b for some torque? C'mon Mark, just get one already and toss those archaic v8's to the scrap pile. Also, a manual tranny is needed for the track, I mean real race track

 

I have spoken to Carl on the phone, and what I told him is he needs to first decide how fast he needs to go and what his competition is. I my region(LA) we have a very good group of similair cars(speed wise) and several very fast occasional racers. I finished second in points last year and my dad finished third in points in the same car. so making every race helps. but to run with the fast guys every weekend takes a fast and reliable car. I run hoosier bias ply slicks, 13B turbo, Haltech ECU, 10psi boost, race fuel, modified double adjustable bilstein coil overs, a K2RD 6 piston willwood superlite brakes, willwood manual brake system, full fiberglass body work. in essence a GT car built around an RX7 turbo II chassis. this car has had alot of work and developement and it can hold its own with RSR's on some of the smaller tighter tracks(with other drivers than myself duing the driving). for the cost of this car you could build some other race cars that would be alot faster and would be easier and cheeper to maintain. namely our new ASC car fits this description. both cost almost the same to build and the ASC car will run about 5-10 seconds a lap faster at any track and will stay with almost any porsche short of a GT3R. the second gen RX7 is a great car to build an IT type car out of as the stock suspension layout is good and there are alot of parts available for it, but to go farther than production racing I would recomend a tube chassis car. the tube chassis car is the next level and is a true race car in that it was built only to run on the track. sorry for the long post.

 

RXHeven-

My car is far from being done yet.

I'm just letting someone else be the guinea pig for putting a T56 behind the GN engine.

Torque talks..... and a 20B will certainly step up to the plate and answer with a roar. But at what cost!?!?

Tim- Are you running the Wilwood brakes that K2RD.com sells? Would 13" or 14" AP Racing front brakes be overkill on a 2600lb FC (whatever the powerplant?).

Thanks,

GNX7