Agreed!!! WTF is up with the turbo and shifting/lag in the video? GT30's shouldnt be producing lag like that right Mark?

Awesome car, but almost every video I see of turbo's being raced are like this!

 

Hey Markski.

I have spoken to Todd about this. He sent over two stronger Diverter valve springs to hold some more boost pressure in the system between shifts. (Maybe 10 psi) This way the Diverter Valves are no longer releasing 100% of the boost pressure. This is what he believes is contributing to the problem.

Chris. You think this might help? Car is at my dealer now - I'll bring it by and we can take a look at it to see what your believe the problem might be.

 

Here OhioGT2 stock internal GT30 old GT2 on 1.5bar ( i guess ) vs A stroker built vette w/nos..That Vette made 700RWHP also.

http://www.youtube.com/watch?v=TUT5_sLv0JE

The vette jump just before Jemie ..Pretty close race

Jemie...Is it also 65mph rolling ? also what is ur speed when he hit the break?

I dont think Keitha need 1.8bar to beat that Nitroused C6ZO6...1.5bar would enough to ran close or MAYBE beat it..JMO

 

That was against a stroked C5 Z06 on a big shot. That Z trapped 141. We ran from a 40 roll and I jumped him by a car since he spun (he was on slicks, I was running 315 DR's). We ran to about 160. I was running 1.5bar and dyno'd 715whp on the same dyno Keithta made his 700whp. That GT2 always ran strong and I didn't experience much lag between shifts.

 

Keith i know these cars pretty well now, i'm sure I can figure it out. I would start with the basic's like pressure testing the car then moving on to dv's, w/g lines, w/g's them self.

Chris Green

 

Keithta -

Even though I myself didn't buy my car to race --I prefer the idea of driving on mountains with Atomic, Humm3, and Greta .
However -- I did take the time to carefully look at the video and raise questions/comments . I'll list them .

1) The Lag -- As others mentioned I did notice the lag . Since I am not a technician I would be guessing whether it's software or the Turbos itself . Part of the problem with larger Turbos of the past was that the immediate jump was delayed . You simply may have needed more road or perhaps the car isn't meant for this type of rolling victory agaisnta nitrous vette .

Possible solution -- I notice in my car I have less HP (approx 600) but also face less lag with my components . The short sprint is just that. I am guessing that the midpoint might be with OEM Gt2 Turbo's swaped into the car and some weight reduction.

2) Nitrous -- Awhile back someone posted an M5 Vs a 997tt 700 with similar setup to yours where the M5 had nitrous. Here's the clip. http://www.youtube.com/watch?v=NhkHryaRCxM

Looked similar to yours with the heavier M5 instead of the vette .

BTW the NON nitrous M5 also ran with the same car and lost and it was posted too.

3)Aside from the safety hazards of the road vs track I can't help but wonder how much Hp the 997tt can take before mechanical problems arise without replacing a lot of the car's internals.

Drive safely and be well.

 

well said and like I suggested... help him out- Im sure its something stupid...
markski

 

keithta tells us about the driveability of your car with the bigger turbos. Also, ohioGT2 were you pushing 715whp on stock internals as well?

 

The car driveability is fine. It feels stock pretty much until you get into the power band. The turbos also are not really laggy at all. The boost comes on about 500 RPM later than the stock turbos but makes a ton more power in the mid range and on top.

There is just a delay between shifts regardless as to where the boost is (1.0 bar - 1.3 bar). I believe this delay may have been there when the car was stock - just not sure if it was that pronounced. Just didnt drive it but 2 days in stock form before I sent it off to Protomotive to get upgraded. So I dont really recall....

Anyhow, as I said before, Todd FedEx'd me a set of stronger Blow off valve springs in which he claims will help with the boost response coming back on quicker between shifts. I'll keep you posted on what happens there. I'll also swing over to Chris's shop in Coral Springs to run through the components to make sure all is on the up and up.

 

Yes, no issues at all.

 

Great Vids!

 

Ok maybe our definitions of lag are different, but mine is when you hit the gas and there isnt boost. Which is what it looked like in the video.

So what is the difference in shift delay and lag? Shift delay is on you, if the car is in gear and you're on the gas, it's not shift delay. Maybe you meant to call it something else. But it sure looks and sounds like lag.

But I'm no turbo expert. I would expect GT30's to spool up faster. That kind of lag is what I got from a Corvette with a low compression 427 and rear mount turbos, almost exactly the same.

 

sounds like your definition of a turbo is a supercharger...

 

Dude..just try to race an 08 viper. Nice video's. That Porsche is wicked

 

both cars are bad ***. str8 beast. especially the z06