T3 GTP build

[Reaper1]

Forget overpriced alumilite. Heavy 1" plywood splitter.. scrape it up all you want and it will never break. Weight in the best possible location for balance as a bonus to the aero.

^^ this and good point on the weight. 2 birds with one stone

Yeah, I brought up the plywood thing, but I didn't think you'd want to use plywood on your car...especially given that you are using mostly top-dollar stuff all over the rest of it. But, plywood does work well. I've seen it used many times.

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Forget overpriced alumilite. Heavy 1" plywood splitter.. scrape it up all you want and it will never break. Weight in the best possible location for balance as a bonus to the aero.

^^ this and good point on the weight. 2 birds with one stone

Yeah, I brought up the plywood thing, but I didn't think you'd want to use plywood on your car...especially given that you are using mostly top-dollar stuff all over the rest of it. But, plywood does work well. I've seen it used many times.

[Johnny]

Yeah, I brought up the plywood thing, but I didn't think you'd want to use plywood on your car...especially given that you are using mostly top-dollar stuff all over the rest of it. But, plywood does work well. I've seen it used many times.

It it had a thin layer of fiberglass over it so you could not tell, that would look okay.

[francois]

Plastidip it!

[168glhs1986]

Plastidip it!

Awesome idea. Won't last long but that's ok + my painter dabbled in plastidip last week

[csxtra]

Instead of Plywood, how about HDPE (the stuff they make cutting boards out of)?

48" x 96" x 1/4" sheet of Black Marine grade HDPE = $119 at McMaster Race Carr (they also have 1/2" sheets but they are about twice as much): http://www.mcmaster.com/#9785t162/=szc9m7

[player1up]

HDPE has a maximum service temp of 180° and a Vicat softening point of 129°, that may not be high enough to deal with track temps.

However phenolic might meet the weight, temp and rigidity requirements.

This whole thing is a compound problem.
Car doesn't steer very well without weight on the front end.
Stiffening the suspension aggravates the situation because we're no longer transferring any weight to the front end. ( just reiterating this for those that haven't felt this problem first hand )

I haven't started looking at the numbers but how much weight are we talking about ( how much is needed ) ?
I'm guessing that a sheet of 1/2"x24"x68" phenolic would be about 20-30lbs. Does that sound about right? I've got to see if the local plastics supply place has anything like that on hand.
Ideally we shouldn't be adding weight to the car, but distributing what's already there to the front.

[bakes]

has anyone thought of relocating the fuel tank to the front end (ie 911) plus you could then use quick fill caps for racing that alone can shift alot more weight on the front end

[Johnny]

But that would add it too far forward, in front of the front wheels.
Only place also would be right at the front bumper, not too safe if you hit something.

[Reaper1]

Weight is simply the byproduct of the parts/materials being used. I can't remember if this car has been on race scales so it can be balanced or not. If not, it needs to be done. Get the car balanced, drive it again, then see where things are at (if it hasn't been done).

If moving things around will help the balance of the car, do that first. Then start looking at things to help traction where it's needed. The whole point of this car is power/weight. Just adding more weight goes against the point of the car, plus it's the last thing you really want to do. Weight is your enemy.

Adding the splitter is not about adding the weight of the parts. It's about generating downforce at speed to improve traction. The downforce created by the splitter should be more than the weight of its parts. If it doesn't accomplish this, you just wasted a lot of time and money. Yes, you will be adding weight to the car, however it should be as little as possible. Yes, it is important to note that the weight of the splitter is going to be in front of the front axle, and down low...possibly on or very close to the water line of the CG (water line = vertical distance from the ground = WL 0, at least for me and this example). If the splitter is added, then the car should go back on the scales to make sure things are still where they need to be as far as car weight balance is concerned.

Another thing to keep in mind it that cars that use aerodynamic downforce enhancements require higher spring rates. Think about a truck and how it sits in the back when there is nothing in the box. Now, imagine it running down the road and the faster it goes, the more weight is added to the box. The rear of the truck is going to sag and eventually it will get to the point where the suspension will hit the jounce bumpers over every little bump. Not good. This is the same kind of thing that happens with aero cars. So, they need the extra spring rate to keep the suspension from sagging too much at speed. So, if you have a car that is not dependent on aero downforce that is set up really well, then add aero to it, that set-up will most likely not work well anymore. I can't honestly speak from any experience setting up an aero car. Just from looking at what goes on, now you have added at least 3 more variables to the car's set-up. The downforce needed is dependent on all the normal things that affect traction, like driving style, track conditions, etc. The needed spring rate and damper adjustment is dependent on all the same things, but now you have to take into consideration as to how much downforce is going to be made, which usually is adjustable, and is speed sensitive. The last thing that I can think of off the top of my head right now is that there is going to be a compromise somewhere. Are you willing to give up some high speed stability and grip for quicker acceleration and top end? Do you need the car to have more low speed grip for long sweepers, or are you on a rougher track where you need the suspension to work more to keep the tire in contact with the road? It's a big can-o-worms. Most aero cars are dependent on speed. You have to drive them fast to stay on the track, otherwise not only will you go slower, but the car will handle like sh*t. I've heard from many people that driving an aero car for the first time is pretty darn scary because you have to do things at a higher speed than your brain tells you should be possible.

In saying all of this the point is that typically an aero car is not a "set it and forget it" deal. It will be different everywhere. Much more so than a non-aero car (non-aero cars still need adjusting, but not nearly as many things).

I'm not trying to scare anyone away from using aero at all. I'm simply putting information out there for people to consider and know about if/when they think about putting aero aids on their car (beyond a simple air dam). I'm excited about this because there are very few TD's that could benefit from this type of modification, and even fewer that would use it. I honestly feel these cars are a good platform to do this sort of thing to simply because they are a race car and they were built with all the things needed to really take advantage of this stuff right out of the box.

Anyway...enough of the book writing

[Johnny]

Mike,

I got a chance to drive my car today. I changed the springs to what you did.
550 rear and 450 front.

Much better!!
Less floaty feel. Well, none now.
The new shocked helped a lot, the springs even more so.
Also when you step on it, the rear doesn't squat like it did.

But for the first time it got loose in a corner under power.
Let off the gas a little and settled in the groove.

I was also getting a LOT more power than I have in the past.
Re-installed the stock turbo, but used the TU header and better intake.
Boost was immediate to 14 psi. This baby goes!

Any way just wanted to let you know about the springs...thanks!

[168glhs1986]

Great to hear Johnny. Glad you found your power drain also. Good idea of putting the old turbo back.

Where do you have your rear shocks set? Mine is 9 I believe.

Headed to Rossien Thursday with Doug and maybe Randy.

Wish us luck

[Johnny]

Good luck, discover great things!

On your GTP, you are running more than 15 psi, did you replace your gauge or does it just go past the stock 15 psi gauge and can tell?

[168glhs1986]

I replaced the gauge with a 30 psi and no vacuum. It's a vdo and matches the stock gauges. I have run 22 psi and that's probably max on my tune / injector combo

[Johnny]

Got a part number for that gauge?

[fishcleaner]

I ran the VDO boost only gauge and it buzzed like hell, switched back to the vac/boost and it was fine, don't know if it was only my gauge or all of them.

[Reaper1]

Did you have a check valve on the gauge? I'm not 100%, but I think using a 1-way check valve for the boost only gauge might help. Just like a MBC you would have to have some sort of bleed hole so that when you go from boost to vac the pressure doesn't stay in the line and the gauge reads your max boost all the time.

[2.216VTurbo]

Mike,

I got a chance to drive my car today. I changed the springs to what you did.
550 rear and 450 front.

Much better!!
Less floaty feel. Well, none now.
The new shocked helped a lot, the springs even more so.
Also when you step on it, the rear doesn't squat like it did.

But for the first time it got loose in a corner under power.
Let off the gas a little and settled in the groove.

I was also getting a LOT more power than I have in the past.
Re-installed the stock turbo, but used the TU header and better intake.
Boost was immediate to 14 psi. This baby goes!

Any way just wanted to let you know about the springs...thanks!

Not sure I understand how you got the power back, we played with various things at SDAC and 8-9 PSI was all you could get. Was there a leak you found or issue with the other turbo or?

[Johnny]

Just put the stock turbo back on.
that intake and TU header work great!!

[2.216VTurbo]

Just put the stock turbo back on.
that intake and TU header work great!!

Oh, I thought the turbo you were running at SDAC had been rebuilt and was fresh?

Sorry for the hijack Mike, but hey, at least we are talking about Consulier's right

[168glhs1986]

^^ Wasnt the wheel clipped on his new turbo and that was causing the loss of bOost and spool?

I dont know much about this stuff so please forgive me if I'm wrong.

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Got a part number for that gauge?

So your thinking about running more than 14 psi ?

Will find for you Johnny.