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Discussion Starter #1
Trying to build a Road Course car. I have HKS Hyperdampers Strut tower bars frount and rear, and a 6 point roll cage. Anything that I can do to make it handle better.

Chris
 

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Wider wheels & better tires
Big fat sway bars
Foam fill the chassis
Remove any unnecessary interior items
Tire pyrometer & air gauge
Caster/Camber gauge
Corner weigh the car



Jeff

P.S. Last weekend at TWS in full race trim our supra
was at 3274 Lbs:D
 

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JWatson said:

Foam fill the chassis
Jeff, have you done this? I was thinking about it for a while, but I had no idea of where to put the foam. I knew if I put it in the wrong place it would rust, which could obviously destroy the car.

Any info you have on this process would be much appriciated. What psi foams did you use? Pourable or injected?

Also, how much does corner weighting help? I was considering doing it, but there isn't any place near me that has corner weighting scales.

I'm trying to get some cloth seats from an NA Supra (non-power, should be lighter) and then have some slots for harnesses made to fit in them. The harnesses really help keeping you planted in the seat.
 

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Use the right foam...

The foam sold at the local Home Depot is NOT, repeat, NOT the right stuff. There's foam just for chassis stiffening out there but I've never found a source that I felt was good. I've got a car, not my Supra, that could use this process so if anyone has a good soource please share. Be careful doing this too as the stuff is VERY sticky and expands like mad. The last thing you want to do is put too much into an enclosed space and wind up damaging something or having it spew all over the place (lol). Everyone I've talked to that has done it has cautioned me about it...

Hrm, and what did you have to do to get a Supra to 3200lbs? Is it gutted or still streetable? Where did you find the most fat to cut? Thanks!
 

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Some people have used this stuff: http://www.farwestmaterials.com/polyfoams.htm

Some this: http://www.itwfoamseal.com/ (supposedly the former is better)

Also see here: http://www.supra400hptt.homestead.com/foam.html

This is what some Del Sol guys had to say about it (I researched this a long time ago, but the rust thing scared me away):

This summer Slater, Jack Ingram, and I started researching chassis foam for the side sills, frame rails and frame crossmembers of our cars. We had all heard about Bellco foam from other boards and the tremendous success others had in increasing dramatically the stiffness of the chassis by foam injection. After alot of inquiries, we came up with 2 products to get this job done. There are 2 types of foam products, pourable foam and injectible foam.

The pourable foam is made by http://www.farwestmaterials.com/ and is called FoamIT and comes in 5psi formula and now I'm told a 15psi strength(Higher psi strength is better). Pourable foam is used primarily on the sidesills of the del Sol. You use it because of its superior strength and the side sill are THE critical area to stop chassis flex. Pourable foam is a mess and hard to use and must be poured down into the holes of the side sills before it hardens. You must remove the plastic side sill from your car to access the holes which run along the length of the sills. You must mask EVERYTHING, EVERYWHERE you are pouring the liquid, because it burns and cannot be removed from paint or carpeting EVER!

The other product we used is FoamSeal http://www.itwfoamseal.com which is an injectible foam product that is a 2 part mixture that is released through a rubber tube with a tip and can be injected into the frame rail and chassis members. We used these on the 2 frame rails which run the length of the car and parallel the exhaust pipe down the center of the car. Off these rails, you will see that the rear suspension has rails of each side that go all the way to the bumpers. All of these frame rails have holes spaced out along them and this is where you will be injecting the foam which sprays out the nozzle end. There are many many areas that you can foam including the front suspension rails, the cross brace under the engine and the rear cross brace that the swaybar runs in front of. Jack Ingram also foamed the area under the rear storage compartments which span the del Sol from side to side.

If you are thinking of doing this, be very careful to wear eye protection and old clothes, because its very messy and dangerous if you get any on your face. It burns and then you literally have to sandpaper your skin to get it off.

This was the most significant suspension upgrade any of us had ever done. It is truly amazing the difference in your car with the top off, because the flex is so reduced that it almost feels a sturdy with the top off as with it in place. Look up the websites I've listed and do alot of reading like we did before you get into this. You just have to carefully plan the areas that you are going to do, mask everything!! that you don't want to get foam on, and have alot of newspaper around to catch the foam that leaks out to the floor because its almost impossible to get it off afterwards! Buster
 

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Chassis foam

You found the right places...we used the foam replacement
sold by Kent...but I think it's manufactured by someone else,
probably FarWest.

Let's see...the windshield pillars, rocker boxes, front frame rails,
the rear rails. Just remember to block off the holes in each section with masking tape and only do one section at a time. A little goes a long way..or should I say fills a large area during expansion. Make sure you look to see where it's going to run down to and protect that area.

Make sure the room is well ventilated, use a respirator and
don't forget to wear gloves. This stuff can get real messy.

Grant,
You asked if corner weighing helps? Yes...a lot. This usually
determines the balance and overall attitude of the car. Check
with Chris Wire at Racecar Engineering in Winter Park. I know
it's a 2 hour drive...but should be worth it. His number is
407-629-7400


As far as weight savings go...first off, ditch the stock seats and
buy a set of lightweight buckets. Our car has the Kirkey
Intermediate 20° Layback seat. Not the best seat for a street
car but a very good choice for racing. I think it weighs about
14 Lbs.

Jeff
 

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IMO

I don't think rusting is an issue. For one thing...your blocking
off the passages that moisture would enter. Don't blow out the cavities with compressed air and you won't put unnecessary
moisture in there.

Jeff
 

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Thanks Jeff.

My car is a street car, and I'm not putting in non-ajustable racing seats. The ajustable ones are much heavier (Anyone know how much the stock non-power seat weighs?) and very expensive.

I was planning on removing the rear seat + seatbelts, relocating a lighter battery to the back, and putting a water/alchy injector tank back their as well (it can double as a windshield washer tank, since methanol is used to clean windshields). Oh and a single turbo :) After that (if I ever get all that done...) I'll try and have it corner weighted.
 
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Discussion Starter #11
Grant - The Recaro SRD type seats are much lighter than the stock seats. I didn't weigh mine before installation, though. They are cloth, as well, and you feel like you don't need seat belts when you're in them...

Jeff
 
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Jeff W -

Did you have to do any wire relocating for the foam installation?

Thanks, Jeff
 

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jkbrauch said:
Grant - The Recaro SRD type seats are much lighter than the stock seats. I didn't weigh mine before installation, though. They are cloth, as well, and you feel like you don't need seat belts when you're in them...

Jeff
Their web site doesn't have prices, but I'd imagine its more than I'd want to pay.

The Corbeau A4s I can get for <$700 shipped to me, brackets and all. Doesn't have a weight, but the Carrera look similar and are 27 lbs. But how much lighter can these be than stock cloth seats? Probably not enough to justify the huge price difference.
 

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You've got more than enough car - now just go get plenty of track time! Like another thread in this section mentioned, it's about 50-90% driver (as you probably know!).

I've been having a heck of time getting to the track for the last few months - havent' had a chance to run with the dialed in single - should be a blast!

Seeya -





BalticSupraTT said:
Trying to build a Road Course car. I have HKS Hyperdampers Strut tower bars frount and rear, and a 6 point roll cage. Anything that I can do to make it handle better.

Chris
 

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Foam

Jeff, you used a 5 psi formula correct? The 15psi formula seesm too strong. And the car took 5 gallons? Also, any other details of the process would help, since this is a completely non-reversable modification.

It seems that the Farwest materials foam is better than the foamseal foam, since it is twice as dense (a search on Miata.net reveals that foam density is directly proportional to its strength). There is a Bellco foam used in Japan, but its very hard to get over here, since its labeled as a hazardous substance. It seems that the farwest foam is the same density anyways.

Could someone please tell me where/what the rocker boxes and frame rails are? I'm a little dense when it comes to chassis stuff.

Thanks
 
J

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Discussion Starter #16
Grant said:


Their web site doesn't have prices, but I'd imagine its more than I'd want to pay.

The Corbeau A4s I can get for <$700 shipped to me, brackets and all. Doesn't have a weight, but the Carrera look similar and are 27 lbs. But how much lighter can these be than stock cloth seats? Probably not enough to justify the huge price difference.
Grant - I can get you the Recaros for the same price ($700), last time I checked. Complete setup.

Jeff
 
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Discussion Starter #17
Jeff,

you can get which recaro's for $700? That's 2 seats for $700?

Cheers.
 

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Re: Re: What else do I need?

DT said:
You've got more than enough car - now just go get plenty of track time! Like another thread in this section mentioned, it's about 50-90% driver (as you probably know!).

Exactly. Get a good alignment and you've got all you need for a great track car. Follow Lance's specs, but add more negative camber up front. Go for at least -1.5 degrees of camber up front if possible.
 
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Discussion Starter #19
carcnoid said:
Jeff,

you can get which recaro's for $700? That's 2 seats for $700?

Cheers.
That's $700 per seat - I wish is was for two. They are the SRD type seats.

Jeff
 
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