High Flow throttle bodies
 

What advantages are there to adding a high flow throttle body?
What problems may occur with tunning and install?
Is there any rule of thumb in regards to maf reading and port size?
Would you need a maf screen with a ported Tb?
SHould you run a seprate maf sensor with a ported tb?
What other mods to consider first?


Thought I would get us started with a few questions, should wind up with some good debate ;)

the only question i can answer is about what you need with the throttle body(not absolutly needed, but help give all the power)

-Bigger gaz pump, may be msd. the throttle body combine with intake-exhaust-headers-gaz pump-msd will ensure that you got all your pony :)

my friends integra got an lsvtec(integra block with SiR head) when he add his bigger throttle body , he run like that some time but the car was close to stall at lights :)

he install after the new gaz pump, fuel regulator, and fuel rail, now it run good, good and smooth acceleration, feel stronger, but stronger on gas too :D

PDad..... might wanna check out CGP and OQCGP....... I've heard some storys about problems with TBs.

Personally I changed my TB the sametime I had my tranny work done (LSD) and now there's something wrong...... the LSD is hooking me up much better, but my topend is much lower. I can't blame the TB..... but I wish I had my old one to try. (had to send it back for a core refund).

Re: High Flow throttle bodies
 

More air = more power, better throttle response

Preferably you would need the MAF tables for the particular MAF sensor your using programmed into the PCM however you could also tune this with an AFC but that is time consuming and not very accurate.

Most modders for our engines go to the LS1 TB or a Northstar TB, those are 85mm compared to our stock 72mm.

These MAF sensors are inline and not part of the TB. They either have a screen built around the sensor itself or don't come with one.

No, if your motor moves more air than the stock MAF sensor can read you should upgrade TB's to LS1 or N*.

Until your outflowing the stock MAF tables I wouldnt worry to much about this mod. I still use the stock TB and stock MAF sensor if that gives you any indication.


Lets get the ball rolling

Re: High Flow throttle bodies
 

I certainly notice that, but I've done many other mods at the same time. From feedback I've heard from others who only upgraded TBs, they also said it had greater throttle response.

The MAF is certainly a major concern, as is whether you want to use a throttle body adaptor or not and what to do about the PCV and TB heating.

The Northstar and LS1 TBs are the same size though the linkage is configured on opposite sides. The N* is for a front wheel drive so it has the linkage on the same side as the L67 TB. The LS1 can work with mods to the linkage (needs to be ground off, flipped and them welded).

If you use a well made TB adaptor you could have a working PCV system. Unless you custom make something, you will not have any coolant flow into the TB therefore you may have freezing problems a -40* C and below.

The Northstar and LS1 TBs are 75.5 MM at the throttle plate versus the L67 of almost 70 MM at the throttle palte. The supercharger inlet is 72 MM stock. When you include the IAC and PCV area of the Northstar and LS1, then the size is 85 MM.

Many use an external MAF such as the LQ4, LS1, LS6 or LT1. Most of these are 85 MM.

You could use a 96-99 Northstar TB with MAF housing that comes with it. From there you can modify the housing to fit the L67 MAF making it much easier to tune.

Cheers,

Great replys, thanks guys.

So if you added a larger throttle body you would would have better throttle response and more power.
The maf table would need to be reprogrammed, now would this be based off the sensor only or the sensor and tb diameter?

I agree the N* or LS1 is the way to go once you cam up but could there be some benfit to porting an L67 tb with just high ratio rockers?

I'd be anxious to see your Northstar setup Foghorn once I make it to Montreal in Sept ;)

It would be a pleasure ;)

Cheers,

So the question remains, do you need to reprogram the pcm if you port your throttle body?
Is this because the factory already had it calibrated to read XX when it Flowed YY and Now it reads XX when it flows ZZ?

In just about all cases yes. Either you can use an AFC or you'll need to reprogram.

Cheers,

Ok then you would want to program it the same ratio as air flow? ie if you gained 10% then you would add 10% to your Maf table?