gametech

iTrader: (1)

Without knowing your transmission ratios and tire size it is hard to make a definitive statement, but I'm willing to bet that 3.73's in that 8.8 would drop your 60's and up your trap speed. I have a similar situation in a GTO where the 3.07 gears require shifting out of 3rd just before the traps, making for a shitty 60 foot and adding an extra shift before the traps, so I lose out on both ends in a 1/4 mile run. The car isn't built for the 1/4, but if it were I would definitely change the rear gears.

RealQuick

iTrader: (14)

What is the exhaust setup off of the turbine housing?

gnx7

iTrader: (28)

A Precision GTS76 Gen2 T4 turbo will make around 1250 flywheel HP and is a billet compressor wheel and dual ball bearing. It is over $2K..... but gets the job done and is a small overall dimension. I ran one in my RX-7..... (gen1 turbo) and then went to a Precision 88 T4 which does spool a little slower.... but the top end pull is no comparison. 3.31 gears and 26" tall tire (2.66 1st gear T56 Magnum).

That is a very cool truck!

Gabbiani

iTrader: (20)

Some answers

RXT clutch

My 1.7x passes are always with a little spin. If it bogs it will be an 11 second pass.

275/40/17

3.08 gears because Ford rear and GM front. They have to match so 3.08 or 3.73. Short tire. I'm about 5600rpm crossing the traps and a little more mph would put me decent into 4th. Trans has the short ratio so 1-3 are actually pretty spot on but 4th is a good drop. I shift into 4th @ 115. To go 3.42 would have to build an 8.5 which I couldn't even find last I looked local. 3.73 would run out of gear in 4th with short tire.

Exhaust is 3.5" downpipe to just past frame rail with 3.5" cutout. Basically 2 90s total before cutout. Rest is 3" and Borla XR1 but cutout is open at the track.

IAT started @ 110 and ends 175. Cooler air would help for sure. 3" already too thick and grill doesn't fit even after cutting it out.

Thanks all

Gabbiani

iTrader: (20)

3.73 even at 7k would be out of gear at 140.

silvea

iTrader: (1)

Ok so your IAT's are super high and that's hurting you for sure. What fuel are you running? Things to consider would be Meth injection to decrease IAT's. If you went with a small shot of nitrous it would add some power to help make you faster as well as decrease IAT which would result in a huge increase in performance. You could even go with like a CO2 sprayer on the intercooler.

CyberGrey Z28

iTrader: (4)

What compression?

Gabbiani

iTrader: (20)

10.5ish - E70-E80 depending on pump

oscs

iTrader: (19)

Since when is 175 super high? Lmao 65* rise from a China cooler isn't that bad at all. Your suggesting bandaid after bandaid and more useless cumbersome BS. His problem isn't IAT it's his SLR. The truck need better gearing not more power.

Puck

iTrader: (17)

While the turbo is on the small side, I would start by hunting down what's keeping your 60' so high. I see you state its getting better every time out, so is it just a learning curve/new build type thing where you're not 100% on the launch technique yet?

You're also trapping at a very low RPM, but I understand the gearing issues with being AWD. With a ~5900rpm peak you should be attempting to trap around your shift points, which I'm guessing are ~6200-6300rpm. 5600 is way off.

There are of course other little things that can be nitpicked at, but I don't think they are the biggest considerations to take.

With the car sitting as-is, dropping the 60' down a bit and getting it to cross the traps at over 6k will be a massive improvement in ET.

Edit: BTW, that is one insanely badass truck. Can't say I've ever seen one like it. Kudos!

Gabbiani

iTrader: (20)

I'd prefer to bring trap up than try to gear down. Can do 3.42s with a built front diff, cv axles, and built 8.5 for @ $4500.... I'd rather add another 10mph. That money could potentially buy a lot of power.

Slave failed last night. Get to pull the trans again today Probably no track tonight.

Gabbiani

iTrader: (20)

Any good resources out there for launching/supsension on awd manuals?

oscs

iTrader: (19)

Don't use Bandaids! Build it! That truck would be awesome on the street you should let it eat.

SLOW SEDAN

iTrader: (13)

What are your shift points and shift drops? We rev that same cam out to 7300 or so, the shift drop then falls right into the meat of the powerband.



Your not far off from Audi weight, we give those things the business off the two step and let the AWD work.

Not sure what tire your running?

93hatch

iTrader: (9)

Buy used precision 76 for 1k and sell your on3

Gabbiani

iTrader: (20)

Shifting 6700ish. Power drops off so fast which assume is the small turbine.
Drops to 4700.

275/40/70 - ET Street rear - Sumitomo front

silvea

iTrader: (1)

I fail to see how meth injection or nitrous would be a bandaid fix. Look at how expensive it would be for him to change his gear ratios rather than add more power. Spray on it and let it eat with the gears in it he has. I have full faith that if he sprayed on it he would trap fast enough to get his trap rpm over 6000 and make a much faster run. Hell even going to a shorter tire might help. You can call them bandaids but I call them cost effective modifications rather than reinvent the wheel at great costs to achieve similar results. No one was ever upset because they added more power

oscs

iTrader: (19)

The OP has made his intentions clear. Good luck .

SLOW SEDAN

iTrader: (13)

Understand the larger cam and small turbine isn't an ideal combo, I've been there with a 236/236 cam and that turbo. We've messed around a good bit with revving engines past peak power so they land in a fatter part of the powerband on the shift. 4700 is awful low and if you revved it out further your probably making more power in the mid 5k RPM range for a better shift recovery.

What size wastegate do you run? With running fairly low boost you could bleed more of the exhaust out a larger wastegate to decrease backpressure a little. We often run dual wastegates if you don't have room for a larger one.

I'm also not a fan of radials when trying to launch a stick car hard. I'd throw a slick on there and let it eat off the line, the slick will recover even if it spins a little.

silvea

iTrader: (1)

So in wondering about my set up, I was just looking at the vsracing version of the pt88. That should offer a pretty significant hp bump and you shouldn't have to really do anything to make it fit. I hear they are an easy 1000hp+ turbo when maxed. Ima start a thread in a second for input on it you might want to check out later and see what people think.