I too have o-ringed heads and a built bottom end and, yet, I am keeping my boost lower. The problem with our motors is the composition of the heads and the small diameter head studs which, together, make it difficult to tighten down the heads in a similar fashion as Supras, thereby making it difficult to prevent the heads from lifting. I genuinely hope it works well for you.

Craig

 

If you are going to run high boost successfully, you need the proper gasket, o-ringed heads and liners and ARP head studs. Don't forget the studs or everything else is a waste of time and money.

 

I have the studs as well Chad -- ARP's best for our motor. Im confident that Scott has the same studs. I am informed that they are still small in diameter compared to Supra studs.

Craig

 

Great start Scott! I can't wait to see what you do at 1.5 bar, as I may copy your set-up over the winter

 

Thanks, Jamie. Here's something you might find interesting, bro; an overlay of a low boost run from my car and from yours...same turbos.

This run is 11.3 psi for me, 12.3 psi for you. I'm running fat during this run (about 11.3 or so) since my car is still being tuned, while your car is running at around 12.5 or so. Because of that, your low-speed boost onset is currently quicker than mine until Todd leans me out. The 1 psi difference between us is good for about 30 hp or so, not forgetting the difference in A/F ratios either.

I'm the solid lines, you're the dotted ones.

 

Scott, why are the curves so similar in shape? I would expect with your head and cam work that the graphs would be substantially different to a car with stock heads... Why does Jaime build Tq sooner with the same turbos? Dont worry, you will have fun with my graphs soon Kevin

 

Kevin,

As I noted above, Jamie builds tq sooner only because my car is currently running very rich (11.3) while it's being tuned. Jamie's A/F is a perfect 12.5 during his run. Once my tuning is complete and I'm no longer running rich, my low-speed boost onset will greatly increase.

As far as why they look similar, I don't expect them to look too much diferent after all is said and done. The main difference between them will be that my car will make a lot more power at the same boost levels and lot more power up top (you can see how Jamie's begins flattening out at around 6,800 rpm while mine starts shooting upwards at 7k rpm).

Remember, we're still in the beginning stages of tuning. My setup is a 1st for a 996TT, so it'll take some time to optimally dial in all the variables.

I should have some more runs to post this evening. Hopefully a high boost run. We'll see.

 

Given that they are both running GT30 turbos, I am not surprised that Scott’s and Jamie’s power curves are similar. My power curve is also similar in certain respects.

Scott’s larger heads will permit greater power than Jamie at the same boost level, but will also likely delay spooling of the turbos just a bit. I would not be surprised if, when all is said and done, Jamie’s turbos spool slightly earlier than Scott’s.

Craig

 

Turbine hotside size, a/r, and wheel determine a huge portion of the 'curve' of the powerband. Headwork and such will alter it's placement on a HP chart but the way it responds will be very very similar.

Why is it the torque curve is falling off so hard?

Either of you guys have a backpressure sensor before the turbine wheel?

What size downpipes are you running?

a near 30% loss from tq peak to redline is interesting.

 

Interesting observation. I just checked and my torque does not fall off any where near to the extent of Jamie or Scott. I suspect Todd will tune out some of that as to Scott.

Craig

 

Hi Scott, thanks for sharing....quite interesting to see the differences. It's great that Todd is able to start building some solid data on all the different set-ups.

 

My car just made 824 rwhp at only 1.38 BAR (20 psi) on C12!!!

Time for some C16!

 

absolutely amazing! congrats scott!

SM

 

Holy HP Batman! Nice numbers!

 

Holy s***. I guess its gonna be PE1000R.