Agreed! The throttle body mod on an NA makes the engine very jumpy. Transitions between accelerating and coasting are very jerky, enough to make your neck sore after some brief city driving.

 

!?!?!?! what are you talking about... maybe your foot is coming off of the pedal way to fast or your dashpot is not working right.... mine is not jumpy at and i have modified my dashpot so i dont have a slow return to idle... could you explain more about why this is because i do not have any jumpiness or jerky transitions.. maybe im lucky but i havent heard of that before

 

Well, I have a NA, and haven't ported the throttle body yet, but I wired the aux plates open. I haven't noticed any real problems down low (well, other than my TPS needing more adjustment, it was WAY off, and is now close, but not quite right). It feels like there's *slightly* less low end torque, but the high end is a lot nicer.

I'm planning to port my throttle body whenever I get time & a few weeks I can be without my car (it's on the list to do when I remove the intake manifolds and clean/port stuff).

-=Russ=-

 

if you gained top end after wiring the aux ports open then your ports were not working correctly in the first place.... there should be no top end gain, only low end loss and believe me i tried it because i wanted to exp it first hand... no better top end and a shitload of torque loss... get your ports working correctly... are you able to turn them with your hand? if not then they are stuck or not opening all the way

 

No my foot is working fine and I've been driving this car since 1991..I think I would know the difference. I did the throttle body mod and the car is jerky when you transition between accellerate and coasting. Mainly in 1st gear.

Don't get me wrong, the throttle response is nice with the TBM but the added jerkyness is not worth it on an NA.

Also, there is about a ZERO gain doing this on an NA. I have a dyno sheet from last year and one from two weeks ago. The only difference being the TBM. The peak RWHP was about the same. IE: I can attribute the difference in HP to temperature...

 

lol well good to know your foot is in healthy working condition... i hope you dont think i ever said the TBM on an n/a will net hp gains.... if anything at all it might be slight more response... of course i did mine when i built my intake so any improvement i felt would generally come from the CAI not the TB mod, however im sure some better airflow is allowed throught the TB, and the jerkyness... now that you say 1st gear i understand what you are talking about, i have a slight bit of jerkyness in 1st but dont notice it in any other gear...

 

Sorry, that was really badly worded. Not the 6th ports - they're working properly. The secondary throttle bore aux butterflies (the ones that get removed in the TBM). I was having problems with power - sometimes the engine would have a lot of power, sometimes it was not making much at all. Wiring the aux butterflies open eliminated the problems I was having with erratic power output, and the engine felt better up at the top end.

-=Russ=-

 

Doing the TB mod makes it a lot easier to port, though. The plates are in the way otherwise. Plus for me the TB mod was another 2.6 lbs of weight reduction

 

haha its always called weight reduction if its not a performance mod.... im the same way i did it for the weight reduction

 

Well... its something FREE to do, and I did personally notice better throttle response, and a little top end... but I also cleaned the K/N filter at the same time

 

The TB mod on an NA should not make any difference to throttle response unless you've done something wrong. The throttle response is improved only on Turbos because the upstream secondary plates are damped (i.e the open slower than the downstream ones). On NA's those plates are held fully open once the engine is warm. So the only difference is a set of open throttle plates are removed. How is that going to affect throttle response or cause jerkiness?

 

hey I don't have this mod done and my car is jerky just as you guys describe. my tps is not perfect, but it is below 2500 and when I let off the pedal there's a neck snapping type jerk.

 

Fix your TPS before you complain about ANYTHING involving a jerk on throttle movement.

-=Russ=-

 

What he said.

 

I value your input.

Yes the plates are held fully open, but they are still in the path of the intake. Also when they are fully open, they don't sit perfectly parallel with the incomming air. they point about 5 Degrees up causing a disruption in the intake. Removing the plates did make a difference, but nothing to write home about. About the same as difference cleaning the air filter.

Maybe the effect of the TB mod on an NA is all mental who knows. I'm not recommending it to anyone with an NA. I took my ported TB off and replaced it with my original unmolested unit. The jerkyness I described is gone.

 

Silly question... the people who are getting jerkiness with NAs and the TB mod, did you readjust your TPS after modding things?

-=Russ=-

 

yes more than likely we adjusted the tps... i know i did and if anybody knows anything about a rotary they would know to readjust this after doing this mod because the tps gets bumped around so much its bound to be off

 

This is a static situation, i.e. is doesn't change as you open and close the throttle, so it won't have any effect on drivability.

Given the number of NA owners who've done this with no problems, and that the problem went away when you swapped TB's, I'd say it was far more likely to be a problem related to that specific TB, and the not the TB mod in general.

There are no reasons not to do it on an NA, just fewer benefits compared to a Turbo.