Should I Do the TB Mod??
 

I know about the bogging out and stuff and how u can't romp on it below 3K RPM......but what are the benefits?? Everyone says "search" but all the threads I open some one says "search" and then no answer is provided.....if ppl would just at least put up a link than all the results would have an answer instead of searching 10 minutes for something that should have taken 1 minute at the most.

Thanks
Hassell

... What is the TB mod (obviously its to the Throttle Body, but you know what I mean :D )?

http://fc3spro.com/TECH/HOWTO/TBM/tbm.html





And my opinion, yes you should. It helps turbos a lot from what I hear, not too hard, and you wont have to worry about cold weather being in CA. Go for it.

yea i did it and it picked up a little on the top end with the TB mod, i would say go for it

I don't like the idea that throttle response is sacrificed below 3000rpm's. Just my opinion.

Who says the throttle response is bad below 3K???

I BARELY noticed any difference... I just have to not "SLAM" it. If I feel like driving a little more spirited... I'm never below 3K anyways.

Definately noticed a little increased top end. While I did the mod though, I also ported the TB. If ya got it out, might as well do it. Just be careful.

If you do the TB mod.. bust out your dremel and port it. If you don't have a dremel, go buy one, you'll be GLAD you did :D You use it so much.

These pics aren't mine, but mine's pretty close.
http://memimage.cardomain.com/member...92_73_full.jpg
http://memimage.cardomain.com/member...92_74_full.jpg
http://memimage.cardomain.com/member...92_75_full.jpg

When/If you do it... take the dashpot off, and see if the bogging is really bad. If so.. just put the dashpot back on, and adjust it all the way down.

I currently don't have mine on. It does bog, but I just got used to it. When I'm not so lazy, and have to replace the MOP I'll put the dashpot back on.

There's a LOT left to be ported in that if you ask me. I went way further on mine. Like, right before the back throttle plates you know how there's that little lip? Same thing on the back of it after the plates? Yah mines completely gone and smooth through the whole way now, along with as much metal as I could grind away.

I'd say definatly do it also. I noticed a nice lil increase. But you have to weigh out the low end sacrifice. Makes it a lil harder to creep through parking lots. But I didnt buy a sports car to creep through parking lots. If I wanted that I'd buy a Honda.

Since when? I have to creep through my college parking lot all the time, no problem here at ALL. I didn't notice a damn difference in low end.

n/a - no
turbo - yes


- Matt

I have only had the car bog once since I did this and it was because I did too much throttle too low.

Other than that it has not affected my driving at all.

sounds good.........thanks guys....now for the $25K question: Why and how does this mod work. What are benefits? Higher top end power?

Better throttle response above 3k I believe. Someone with a hybrid turbo was having problems reaching full boost too IIRC, and the TB mod helped quite a bit. I don't know all the reasons for turbo, but I believe those are some main ones.

oh, ok.....thanks.

Hmmmm, mine's real touchy on the throttle. I dunno. Maybe its just my car.

Maybe, I've never noticed a problem, and my friend with a TII hasn't had much of a problem either. Or maybe we're just the lucky ones, who knows.

I got rid of all the little lips and/or bumps... but didnt go as far "down" here:

Just kinda sharpened it a good bit.

i just did this last weekend on my car and i was really happy i did. It's only bogged once on me and that was my own fault for going uphill in too high a gear at too low a speed. I really like the way it runs, and it sure cleaned up things a lot.

i ported mine out alot more than that... and i love it on my n/a
https://www.rx7club.com/forum/attach...chmentid=67292

and if you stay within your "bandwith" your car should not bog... stay high on the rpms

I did mine more like cwsttu's, but I went even further. I always seem to do that though, go as far as I possibly can, sometimes thats not a great thing though :p:

Anyways, mine is pretty much like his posted, I'd say if you're going to port as well go that far.

mines the same way
check your tps
if your tps your throttle is going to be very touchy and kinda jerk when letting off the trottle or getting on the throttle

as far as the mod goes on an N/A it prolly isn't going to do much if any real good
on a turbo it should help the turbo start to flow a little ealier and boost up
as far as the top end I really don't se ehow it can add that much


if anything would like to see dyno before and after on the thing done the same day around the same time

haha ddub i know i could have gone farther but i had to get my car running again... one day when i port the manifolds im gonna redo my TB porting on another one and tap screws cause i had to use jb weld (ducks and runs)

Yah, :werd:

I could have even gone further, but just like you I wanted to get it done and my car up and running!

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 :p:

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 :D

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.