LS1 Motorsports Single Turbo Update: DYNO GRAPHS!

MIGHTYMOUSE · 01-16-2003, 08:36 AM

Straight From the fires of Mount DOOM!

7psi, pump gas, stock valvesprings(gave out)
http://www.ls1motorsports.com/images/498HPDyno.jpg
9psi, 50/50 race gas mix, new SLP springs
http://www.ls1motorsports.com/images/534HPDyno.jpg

The full page: http://www.ls1motorsports.com/Single_Turbo.htm

AzzHauler · 01-16-2003, 09:54 AM

Talk about an ass-load of torque. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> I'm gonna need to run like 20psi to keep up with your 13 or whatever you decide on. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

smokinHawk · 01-16-2003, 10:56 AM

Did shawn have a ls6 intake on his car?

got to love that torque!

Rob Raymer · 01-16-2003, 11:19 AM

<blockquote>quote:<hr />Originally posted by smokinHawk:
 Did shawn have a ls6 intake on his car?

got to love that torque! <hr /></blockquote>Smokinhawk, you're slipping on me....Of course he had an LS6 intake...they came stock on '01-02 models. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

FASST · 01-16-2003, 12:22 PM

forged internals I assume? Stock cubes? Nice numbers. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

Rob Raymer · 01-16-2003, 12:50 PM

<blockquote>quote:<hr />Originally posted by FASST:
 forged internals I assume? Stock cubes? Nice numbers. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" /> <hr /></blockquote>No, completely STOCK engine and drivetrain. The only thing not stock (besides our turbo kit), was the fact that he was running open exhaust.

VINCE · 01-16-2003, 12:51 PM

Those are pretty stout #'s.. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

smokinHawk · 01-16-2003, 12:54 PM

<blockquote>quote:<hr />Originally posted by Rob Raymer:
 <blockquote>quote:<hr />Originally posted by smokinHawk:
 Did shawn have a ls6 intake on his car?

got to love that torque! <hr /></blockquote>smokinhawk, you're slipping on me....Of course he had an LS6 intake...they came stock on '01-02 models. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> <hr /></blockquote>ah didnt notice the year.

Reckless · 01-16-2003, 02:16 PM

I was wondering the same thing? Are you sure it isn't a fuel supply issue Rob? That hp curve sure does nosedive on the top. Did you monitor for knock and a/f?

Rob Raymer · 01-16-2003, 02:27 PM

His car still had the stock fuel pump at the time also. We were waiting on the release of the Racetronix pumps for the "plastic tank" F-Bodies, but they weren't finished yet.
We ended up shipping his sending unit to ARE to gave them custom modify it with a Walbro 340. At the same time, Shawn changed valve springs and pushrods as a precautionary measure.

Since it still had the stock pump and valve springs, I never planned on pulling past 5500 anyway. I was actually off the throttle (but still in gear) at the point the graph starts to drop off. We were doing a "coast down" to check for drivetrain balance issues.

Hope that helps.

ExtremeZ28 · 01-16-2003, 05:33 PM

thats freakin crazy <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> i'm gonna be the slow guy in richmond its lookin like <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" />

Sears · 01-16-2003, 06:11 PM

Man that is awesome on a stock motor. How hard was it to tune?

Justin

chasgiv3 · 01-16-2003, 06:19 PM

I take it this is a 6-speed car?

When are you planning to run it to 6000? I'd REALLY like to see the dynograph on it.

Keep us posted.

chasgiv3 · 01-16-2003, 06:22 PM

<blockquote>quote:<hr />Originally posted by MIGHTYMOUSE:
 Straight From the fires of Mount DOOM!

7psi, pump gas, stock valvesprings(gave out)
http://www.ls1motorsports.com/images/498HPDyno.jpg
<hr /></blockquote>Why would stock valvesprings give out? Very strange. When you say gave out....do you mean they floated? They broke?

MIGHTYMOUSE · 01-16-2003, 08:03 PM

the sketchyness of the first graph is probably a combination of the valves floating a little and the leaning of the ratio together..

the more boost you run, the lower your valve seat pressure gets.. check the geometry

say a 2" valve, thats area=pi*rad^2 = 3.14"^2

3.14"^2 * 7psi = 21.98 pounds of seat pressure removed from the spring, for a stock spring thats like a 25% drop in seat pressure. so stiffer springs are needed to hold on to the cam.

this is right.. right?

RICE ETR · 01-16-2003, 11:02 PM

yep.... that's right.... also the same principle applies to the exhaust valve... although smaller in rad, it can sometimes see up to 30psi of back pressure.

So you can see where weak springs just can't keep up with following the cam with all the extra force that boost/backpressure causes, pushing against them.

Phate · 01-17-2003, 01:08 AM

Great job Rob!!!

Nice #'s...keep us informed on how the FAST installation goes.

Thanks,

Scott

RICE ETR · 01-17-2003, 01:13 AM

Rob....... seriously... u DA man!!

awesome numbers.... so i just sold my turbo kit, i am thinking it's about time for me to send you a deposit.... <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

CRASH 02 · 01-17-2003, 01:19 AM

I am new to the turbo seen so bare with me on this. Why did it fall off so hard and so fast? I know it made good power down low but from 4,000 it lost 100hp and 250 ft/lbs. Why is that?

chasgiv3 · 01-17-2003, 11:10 AM

Just so everyone is clear here. The valves (once open) has pressure on the backside of the valve where the stem attaches.

This pressure become really important as the valve spring attempts to seat the valve closed. With enough pressure it can overcome the total force of the spring attempting to close the valve.

Honestly I never thought about that dynamic before. Since I have aftermarket springs I never ran into it. But it definitely makes sense.