Idle setting with NW90
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From: Phila, Pennsyltucky
Idle setting with NW90 I have a NW 90 on the FAST manifold. At start up it surges pretty bad but a minute warm up its fine. It also seems to idle a tad higher than before. I played with the blade screw but nothing seems to get it just right, It idled perfect before. I didnt think you hav eto drill out the hole.
Mine does the same thing, I just put it on about 3 days ago. It usually levels off after it goes above and below the idle point about 3 times. I think you need to set the blade as far open as you can, and have it still idle where you want it. This causes the IAC valve to be as CLOSED as possible for normal idle, giving it the ability to open farthest when it needs to. Does this make sense. 
The IAC valve will cause the car to idle at the programmed RPM, reguardless of where the blade is located. If the blade is open TOO far, the IAC valve can only close, then it will idle at whatever it has air for.
What did it idle at before?
The IAC valve will cause the car to idle at the programmed RPM, reguardless of where the blade is located. If the blade is open TOO far, the IAC valve can only close, then it will idle at whatever it has air for.
What did it idle at before?
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From: Phila, Pennsyltucky
it idled around 850 ish before now it sits around 950 ish after. We have the same issue apparently. I think theres a way to correct that early start up surging though. Drilling that hole out might be it, i dont know.
Originally Posted by STRIPSTAR
it idled around 850 ish before now it sits around 950 ish after. We have the same issue apparently. I think theres a way to correct that early start up surging though. Drilling that hole out might be it, i dont know.
1 2 3 NOT IT!!!!!!
I drilled mine. NW has a pretty small hole in the blade. I tried working the blade with the set-screw, but it gave me too much TPS% and it would throw me into a non-idle timing/fueling cell. Drilling the blade is fine. Worked great for me. 
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
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Set screw worked for me. The TPS% can be overcome pretty easy as well. Drilling works just as good, but if you cahnge cams you may need a smaller hole. I talked to NW about this and he prefers the TB to be drilled. You can always buy a new plate from him if needed.
Dan
Dan
Nick is right. By drilling the blade, you leave more of the factory idle setting intact. Messing with idle airflow and IAC effective area tables can really mess up your low speed driveability. Better to stay stock if you can.
Great info Patrick!
I noticed the hole was seriously small when it got here. It looked to be about 3/32 or so, about what size did you drill it out to? My car is cam only with the F14 on a 112.
I noticed the hole was seriously small when it got here. It looked to be about 3/32 or so, about what size did you drill it out to? My car is cam only with the F14 on a 112.
I just got my NW 90mm today.. nice piece.
It will be going on my already tuned 408.
I had drilled my stock TB a while ago, should i just go ahead and drill it to the same size? Sometimes i wonder if my random hanging idle problem is related to drilling my TB. 3/3 tuners have not been able to fix it.
It will be going on my already tuned 408.
I had drilled my stock TB a while ago, should i just go ahead and drill it to the same size? Sometimes i wonder if my random hanging idle problem is related to drilling my TB. 3/3 tuners have not been able to fix it.
I would go easy on the TB hole size. If adjusting the set screw won't fix it by itself, then drill only a little at a time plus adjust set screw. Big cams are alot worse and require more air. My 230/234 didn't even need a bigger hole, my Trex did. You just have to tinker a bit between drilling and the set screw.
Dan
Dan
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From: Phila, Pennsyltucky
I just drilled it out with a 13/64 drill bit. Now it idles great and drives great. i went with that drill bit size b/c it was slightly larger than my old TB hole.
Now new problem - theres a good puddle of oil from the pcv system already in less than 200 miles. ****!
Now new problem - theres a good puddle of oil from the pcv system already in less than 200 miles. ****!
