Some of you may already be aware of this but I wasnt before last week. Apparently many people have had issues with their Nick Williams throttle bodies on forced induction applications. It seems the tb motor is not strong enough that when the blade is fully open, the forced air starts to close it at higher boost levels. I guess its at just enough of an angle for it too happen as well.

In my case, the tb blade starts to close at around 16psi and by 20psi it goes from 99.4% open to 62% open! It will also set a code and go into reduced power mode. You can play with the values for the codes but it wont stop it from happening and killing power. The power and boost curve were flattening out by 6k rpm because the dang tb was almost half way closed.

So anyway, Nick Williams does sell a tb for boosted applications with a stronger motor. Looks like they got a few complaints, especially when people are paying $650 for a tb. Unfortunately the new tb is around $750-800 so its not cheap. But there arent too many 102mm drive by wire options.
Heres the part number if anyone needs it.
Nick Williams 102mm for boost: SD102MMSC

 

In a boosted application no need for a larger tb. I have made 920rwhp with a stock 78mm tb. Plus I have read of many complaints with the NW tb even when normally aspirated.

 

So are you going to try their TB ? I heard the ls2 silver blade TB has had good success with high boost. What boost level will you be maxed out??

 

How much boost you running??

 

18 lbs

 

I'm not getting into whether something is "needed" or not since every application is different. Even though I'm not going to argue that a larger tb has the potential to make more power, which they do, I have also made plenty of hp with a stock ls2 90mm tb. That's not the point of my post though. This is just a heads up to NW tb owners.

Since I work with a forum vendor and have the Nick Williams tb's available to me, I will be trying their boosted tb and sharing my results. I should be seeing 25psi from my Ysi. Worst case I still have my ported stock 90mm tb.

 

Now that will be interesting.

Please do share, as soon as you'll get the results.

 

I'm having same issue on my 402/ysi setup up. I'm making 23 psi and at times messing around car will go into reduce power. Kinda a pain in the ***.

 

Check what code it's setting. If it's a tb code then you know that's your issue.

 

I cleared dtc but I think it was for ap correlation

 

wow what a coincidence, this is the same thing that happened to Leroy in Cleetus' newest video.

 

Itll be a P15xx code

 

Haha yeah I just saw that. Seems to be a pretty common issue on high boost applications.

 

I had the REP problem for long time and tried every thing to solve it but it seems LS1B ECM will not accept it
my problem is P1516 code which will be set with half throttle and medium boost but not with WOT and full boost
I tried the normal NW102 and the new boosted NW102 version with the same issue
I'm going back to stock 90mm TB now and call it aday
My only issue was that i need to put a spacer between my 102 sheet metal intake and the 90mm TB so it will not leak boost at high boost level
no i will solve this problem by welding the spacer in the front of the intake manifold

 

Are you guys sure your blades are closing or are the codes being set from airflow limits in the ecm? 2 bar sdtunes? Or 3 bar sd tunes ? I did a little scaling and it solved my issue on my 3 bar...I've pushed an f1x to 23 psi and no issues on silver blade ls2 Tb

 

In my case its closing from 99% to 62% open. You can see it real time log on the lap top. This post is specifically about Nick Williams throttle bodies.

 

In my case just closed in medium throttle accelaration when the turbos spools
There will be too much strees on the TB motor so after release the peadal it will go in REP
I'm sure its not airflow related
As all my airflow tables maxed
If its an air flow related it will set P1514 not the damn P1516 code

 

NW 102MM only gave me problems and I had multiple tuners worked on it, from Breathless Racing in South Florida all the way to Vengeance Racing in Georgia. All I had was a mild Comp Cams XER273HR 224/230, so I sold it and got myself a ls2 and never look back, happier ever since.

 

Silver or gold flap??

 

Silver and Ported and there is not much difference in size compare to the 102mm .......... but I do have the 102mm Intake from LSXR ....... The gold doesn't work with the LS1 because the wiring is different.