CTS V throttle issue on nitrous

[stonemonk9]

Actually bought them all except for one base on people telling me how to fix the issue. Started with stock 87mm. Needed more air. Was told to buy an LS3 90mm. I had the flutter issue. Was told it was just a bad one. Replaced it. Had the same issue. Got it Ported. More flow same issue. Bought an LS2 at the recommendation of Mike Norris. Issue solved. Not enough flow though. Bought a NW 102 (using stock ls3) Had flutter issue. Bought a TPIS and issue was gone. Magnuson asked me to test a 108. Has a LS3 set of electronics. Has flutter of about 3 to 4% at 5800-6300 rpm but does not cause DTCs. Gave me 50 more HP. Car moves 720 g/s approx. 1500 cfm at 6600 rpm with 850 RWPH and approx. 1000BHP. Very expensive lesson on TBs. If you want to see if you have an issue. Log the TB position from the PID not the sensor. Go WOT throttle until about 5500. Let off then immediately go WOT. Many times it will great a DTC, sometimes will shutdown the engine until cleared. If does not do that look at position on log. On second WOT may go to 99.9% but then flutter back an forth between 95 and 99.9. On cars with larger air requirements the flutter just happens on a long hard pull.

Great info on these TBs. Except now I'm at a loss for which direction to go, don't really have a 102/108 in the budget at the moment. The car managed 138.6mph with the 90mm throttle closing a bit paired with some terribly slow shifting, and being down 1.5lb of boost so things look promising. Do you recommend a ported ls2 for my situation? I did look back at a old log with my stock lsa TB and noticed it does show a bit of flutter also, but only around 3/4%.

In regards to what your saying about getting in and out of it to test the motor, that's exactly what happened to me. Towards the end of the night the track went to shit and I had no traction, had to get in and out of it which shortly after getting back into it the reduced power light would set. The log above shows it, throttle plate closed to 50% after getting back on it then reduced power mode kicked in. Happened twice back to back.

It's a never ending battle... lol

[jsllc]

Great info on these TBs. Except now I'm at a loss for which direction to go, don't really have a 102/108 in the budget at the moment. The car managed 138.6mph with the 90mm throttle closing a bit paired with some terribly slow shifting, and being down 1.5lb of boost so things look promising. Do you recommend a ported ls2 for my situation? I did look back at a old log with my stock lsa TB and noticed it does show a bit of flutter also, but only around 3/4%.

In regards to what your saying about getting in and out of it to test the motor, that's exactly what happened to me. Towards the end of the night the track went to shit and I had no traction, had to get in and out of it which shortly after getting back into it the reduced power light would set. The log above shows it, throttle plate closed to 50% after getting back on it then reduced power mode kicked in. Happened twice back to back.

It's a never ending battle... lol

Hard to recommend but until I got to 750RWHP a ported LS2 worked fine. After that the vacuum was so great that I could not really get any more air. If porting use VMax. That guy is great to work with. What are your goals? How are you planning on getting there?

[jsllc]

108 is the one out of Australia that Magnuson sells and it was a Heartbeat with the 108 inlet... Make sure you port your new inlet to match the blower and TB - ours had some pretty serious core shift or something in it - almost a 1/4 offset in areas... I just said I was surprised you didn't have more issues, not that you didn't have issues - we were the second ones out there as far as I know to test the 108's on the magnusons - I told them they had some design issues then Our ZL1 was still slightly detuned putting down what it did with the magnuson - fresh motor and all - really wish they made a bigger blower... It'll eventually be put back on pump gas, then we'll see just what it'll do Was having to run WAY too much timing on race fuel and didn't want to risk putting any more in for power...

Bigger blower, maybe...The new president is creating some changes. All for the good I believe. I was running 26 degrees with 16psi. Sound about the same as you? 105 octane VP race fuel?

[GHuggins]

Bigger blower, maybe...The new president is creating some changes. All for the good I believe. I was running 26 degrees with 16psi. Sound about the same as you? 105 octane VP race fuel?

On 109 I was having to run 36 degrees up top - should be around 22 to 24 possibly on 93... Made me wonder if our engine builder put the cam in it I had designed for it especially since it was a 9.5:1 compression motor all though it wasn't the best cylinder filling cam up top? 17psi at our altitude was all I was able to squeeze out of her = 18psi at 1200 feet...

You that tight with Magnuson? Were a dealer and haven't heard anything about the possibility of a bigger blower??? I hope their getting their act together though. Was rather upset with them on what they did to us last time That will be one hell of a torque maker if they do

[stonemonk9]

Hard to recommend but until I got to 750RWHP a ported LS2 worked fine. After that the vacuum was do great that I could not really get any more air. If porting use VMax. That guy is great to work with. What are your goals? How are you planning on getting there?

Shooting for 9.5x on boost and faster on spray.

[jsllc]

Shooting for 9.5x on boost and faster on spray.

Well if your goal is 750 or less without NOS then according to guys smarter than me you should be fine with a ported LS2. According to the VMax flow bench an LS2 ported moves about 1100 cfm on an NA motor. According to Dynojet, Kenne Bell an others it takes roughly 1.5 CFM of air per HP. Simple math says you should get there.

[jsllc]

On 109 I was having to run 36 degrees up top - should be around 22 to 24 possibly on 93... Made me wonder if our engine builder put the cam in it I had designed for it especially since it was a 9.5:1 compression motor all though it wasn't the best cylinder filling cam up top? 17psi at our altitude was all I was able to squeeze out of her = 18psi at 1200 feet...

You that tight with Magnuson? Were a dealer and haven't heard anything about the possibility of a bigger blower??? I hope their getting their act together though. Was rather upset with them on what they did to us last time That will be one hell of a torque maker if they do

Sent you an email on this.

[stonemonk9]

Just a small update, swapped on the stock lsa tb and have practically no fluctuation. 99.6-99.2 through a 3rd gear pull.

[jsllc]

An LS2 ported should do the same with more air and be the end of this issue.

[JBZ]

An LS2 ported should do the same with more air and be the end of this issue.

I just looked up the ls2 throttle bodys online, man they are double the price or more of the ls7.

Did i read it correclty that the blade opens in the opposite dirrection of the ls7/lsa so they need to be mounded with the motor facing the driver side vs the normal passenger side?

[jsllc]

You can mount them either way. I had to mount it with the electronics facing the driver's side for clearance of the SC pulley.

[stonemonk9]

An LS2 ported should do the same with more air and be the end of this issue.

Well I ran the car last night with the stock TB, saw 139.6 mph on boost only. So it actually picked up some power but I'd say it's either due to the weather or just the fact that it wasn't closing.... I'm actually considering a stock ported one just due to knowing it'll work. It's that or bite the bullet on a 102.... O

On another note on a very small shot of nitrous coming on in second shes going 142.3mph. Can't wait to start hitting it with more spray and see it come alive.

[Trackman101]

Any updates?
My 108 continues to close. Looking for a fix.

[jsllc]

Any updates?
My 108 continues to close. Looking for a fix.

SEMA is supposed to show some TB fixes.

[schpenxel]

NW is supposedly coming out with some new stuff with stronger motors

[GHuggins]

Any updates?
My 108 continues to close. Looking for a fix.

Sema is supposed to have Magnuson's redesigned blowers and their new big supercharger and the redesigned 108. Nick may or may not be there with his new 110 and 112mm throttle bodies. Not sure if he bothers with Sema or not. I don't recall ever seeing him there.

But to fix your current problem give Nick Williams a call. He's got the motor assembly to cure your problems. So far has worked for our 108.

[Trackman101]

Anyone go to SEMA? Any new throttlebodys or fixes for them?

[GHuggins]

Give Nick a call - I know his beefier motor will fix it...