It only takes a matter of minutes to swap the seats. I built a frame to hold my side mount Cobra’s mounting to the OEM four bolt holes .. so the swap is easy! While I agree with Howard’s point, my seats are sooo tight side to side that my hip bones are pushed thought the padding against the CF shell.
I had heard that the way to measure your hip width for seating is to simulate a 1g side load by measuring your hip width while laying sideways on the floor. Hip compression is supports to be about 1 inch from normal. The resulting fit is NOT for the street.

 

After installing and using a racing seat (Kirkey Deluxe Road Race) for the last two events, I can't believe I didn't do it sooner.

I have a thicker butt and head-rest pad for the drive to and from the track if I'm not trailering her, but swapping out the stock seats takes less than 10-minutes, especially since I got mine with a FD stock seat rack already installed.

HIGHLY RECOMMENDED!

:-) neil

 

Are there any safety issues with regards to fixed back seats on a non-roll caged car?

Perhaps we should break out this topic of seats into a Safety Equipment thread? Discuss seats, harnesses, roll bars on dual duty street + track cars?

 

+1 Yes, I think we should start another thread regarding all this. As i get older, the safety aspect of this is getting more important.

Another reason I have been thinking of doing a racing seat is to properly take advantage of the 5 point harness.

 

Yep, the 5-point harness works so much better with a REAL racing seat.

I do have a seat-brace attached to my Race-Shop roll-bar setup.

:-) neil

 

im kind of suprised nobody has really mentioned this....

On the japanese RX-7's (knightsports, RE, FEED) If im not mistaken, there spring rates are SUPER high, and sometimes reversed (17K upfront 18K back). They use street tires also, usually NEOVAS or RE01R at pretty normal widths. Clearly these cars demonstrate excellent handling. HOW?

I dont disagree with Howard Coleman's suggestion of ~ 6K back and 8K rear. I am currently running these rates with Koni Yellows. (using TEIN S-tech springs). I am just curious as to why our Japanese friends use such high spring rates and how they manage to make it work so well. (shock setup/settings, swaybar stiffness upfront vs back) Maybe we can learn alittle from this.

When I watch videos of these cars I notice they accelerate MUCH harder and earlier than I do on/out of turns without kicking the butt out. (keep in mind were both using similar tires and I have less power) I find all this very intresting and I'm hoping some people that use similar setups or know more about the Japanese tuner cars can chime in. Thank You


BTW: My car settings are pretty much what everybody recommends. 6Kr 8Kf. Koni; 85%stiff front (1/4 turn from stiffest) 25% stiff back. -1.2 camber all around. 0 toe. etc.

 

Keep in mind that we are not talking a full race setup in this thread. We are talking about a compromised setup that can work on the street and the track. 17k springs don't work on the street unless you are a sadist.

 

^yea im pretty sure 17k would be suicide on streets, but im just exploring the idea.

 

i think this was touched on before, maybe not this thread however...

IIRC, it had to do with the downforce produced by the kits, canards, wings,etc that they use. i believe it was mentioned RE-A did some wind tunnel testing as well. pretty interesting read anyhow.

 

Also, higher rates do load tires faster upon weight transfer, making them quicker to react - fully loaded - to driver's inputs (steering, braking, accelerating).

If track surfaces are very smooth (as in Japan), compliance (main reason for using softer springs in performance oriented applications) becomes less important.

In my experience, I found the car much easier to control in autox after upgrading my springs from OE to 14 Kg/mm all around. But I appreciate how very good drivers - the ones who can anticipate their inputs early enough to account precisely for the delayed tire loading - may still prefer using softer rates for better tire compliance.

As for street use, clearly softer suspensions isolate you better from road harshness. However, if the shocks are properly valved (soft compression), using higher rates is not as sadistic or suicidal as you may expect - unless you regularly drive in Manhattan of course...

- Sandro

 

wow great info !!!!!!!!!!!!!!!!!!!!!

 

we tried to drive the track car on the street, and with very high spring rates bumps literally launch the thing in the air...

 

Agreed that spring rates aren't the whole story as far as ride on the street. I remember when I went from Eibach pro-kits to the GC 500/400, it actually rode BETTER, because it didn't crash down over bumps and dips the way it did before.

By the same tolken, 500/400 rates just didn't cut it anymore running 285/30 Hoosiers on track, and turning quicker times. Even stiffening up the shocks, the car still pitched too much under braking, and wallowed a bit in high-speed turns. Fat sway bars aren't going to fix that, especially the under-braking part. 650/500 with GABs fixed it, though it's alot harsher on street.

 

I agree on the topic of valving and spring rates. Though softer does work better on the street. I experimented with various spring rates on the same shocks and wind up going down to 450/350 and enjoyed the slightly improved off-track / on-road manners compared to 500/400.

Also, keep in mind that the Koni shocks on your old setup were pretty well worn by the time you got rid of that setup by selling them to me (at a good price that I was very happy with). One of the fronts was completely blown and even the lower shock bushing was cracked from wear. Now that I've had them revalved at Tripoint, they are quite different from off the shelf Konis I was running previously. They work a lot better on track but are a bit harsher on the street. Can't have your cake and eat it too, eh.

 

Howard do you have any experience setting up an OEM style clutch pack...such as the turbo 2 S4 diff?

I'm curious if I should just put it back together how it came or if I should be messing with the breakaway and possibly putting more clutch plates in.

I will have an LS2 making 450hp/450ft lb

It will be an all purpose vehicle with street manners being most important...so no chattering around corners etc.

 

"spring rates are SUPER high, and sometimes reversed (17K upfront 18K back). "

rates in this range are used purely to offset aero downforce. Indy Cars currently have so much downforce (3G) that they could run on the ceiling. the springs are needed to keep the chassis off the ground.

in the real/street world rates in this area would chatter the tires and lose grip.

'sorry can't help you on LSD setup.

hc

 

Howard,
Hello. Just spent the day reading almost the whole thread. I'd like to improve the road ride of my stock R1. Looking for better bump compliance. I have stock wheels, Potenza So2, Koni yellows, and all new suspension rubber (upper spring mounts, etc.). Would the Eibach springs do a better job than stock R1 springs or should I look into the coilover option? I'm running the Koni's full soft on the street. Front height is 25.5" and rear height is 25.75".

 

thank you

 

"Looking for better bump compliance. I have stock wheels, Potenza So2, Koni yellows, and all new suspension rubber (upper spring mounts, etc.). Would the Eibach springs do a better job than stock R1 springs or should I look into the coilover option? I'm running the Koni's full soft on the street."

first off... make sure your tire gauge is accurate and that you are running no more than 30 psi front and 27 rear set cold.

second... just FYI, there is no such thing as R1 springs. the only specific R1 item is the dreadful R1 shocks which should be used as doorstops.

as to springs & shocks... you are sort of backwards in that you have the stock springs and stiffer shocks. i recommend stiffer springs first and shocks second only if you want a bit more (actually less) reaction time.

so to get better bump compliance... bolt in a set of Eibach ProKits and stock shocks. the stock shocks control the 350/255 Eibachs perfectly. i have dynoed the stock shocks so my info is correct. the Konis are overdriving your springs.

Eibachs may be out of production so you may have to get them off the classifieds (not too big a problem w some patience) or as an alternative i recommend two Tein springsets.

Tein S Tech 440/320 drop is 1.4 fr/1.3 rear

Tein H Tech 390/290 .8 front/.7 rear

either will work fine.

don't forget to reset your camber as it changes w ride height changes.

most people initially react negatively to my suggestion of just a spring change and the stock shocks... until the DRIVE the setup.. after that i get lots of PMs from happy FD pilots.

if you plan to do really aggressive tracking you'll need the non OEM shocks but if you want to go fast on the street the Eibach/Tein springs w OEM shocks are excellent.

good luck,

howard

 

Hey Howard,

Here's a video of my car last weekend at the track. track temp was 39F so I had no traction what so ever...... It wasn't that fun at all. new things done to my car was converted to E85 (currently making 504rwhp on my mustang dyno or around 550rwhp on dynojet) and added a splitter on the car.

http://s371.photobucket.com/albums/o...sandbrakes.flv

 

http://s371.photobucket.com/albums/o...ilpressure.flv

 

pic of the splitter

http://www.facebook.com/photo.php?pi...&id=1496172346

 

Sweet Steve! Thanks for sharing. What types of tires are you running ?

I loved your spin!

I've been happy with Kumho 710's in the WINTER, and BFG R1's in the summer here in north Florida.

Did you fabricate your own cage and dash ?

:-) neil

 

Neil,
I run the Yoko 280 front, 320 rear full slicks. They work great when warm but you can see from the video that they were worst than street tires when cold. As for the cage, it's made by ISC in florida. This car was originally setup in Florida by Cam at pettit for a customer who was suppose to use it for IMSA race. Everything was stripped and built properly with a 25Gal fuel cell.

 

once you get the car dialed NO ONE is going to touch you on a road course. a 550 rwhp FD? supersonic.

as mentioned in post one of this thread the ultimate challenge on the FD as lap times drop is hooking up the rear end. and, of course as hp goes up that challenge becomes greater.

race tires don't work at less than 140 degrees and i am sure in the video you hadn't quite reached that point. combined w axle bending torque you must have been very busy

i am concerned about the splitter. given the need to add rear grip w alot more ponies the splitter loads the front quite a bit. if you load the front you unload the back. i don't know if you are running a rear spoiler but you will need one w that splitter. further, when you start adding downforce the primary spring function changes to resisting downforce and maintaining rideheight to offset camber gain.

you will be busy this year but the car has awesome potential.

BTW, i really like the idea of running alcohol (E85). road racing is so demanding on our 159 cu inch motors especially when they are pumped up w alot of air. the cumulative thermal effect of running a number of laps presents a serious challenge.

nothing provides the cooling of alcohol.

i will be attempting to break 200 mph at the Texas Mile in oct and will be running straight methanol. i figure the mile will take around 25+ seconds and it will require around 600 rw to get it done. that's alot of stress and methanol will give the motor the best chance of surviving.

on another note... and again re-enforcing something from post one... i noticed a crew chief at yesterday's Daytona 500 saying that they had been going back and forth changing Biffle's tires by two tenths of a pound of air!

that underscores how important the right tire pressure is. and you can only figure it out w a pyrometer.

good luck in 2010 Steve!

howard