Me and my brother were disscussing whether you gain or lose horsepower with a larger one. I thought you would gain with cold air. He thought not. Does anybody have a 62mm? If so, did it help or not?

 

If you have modified anything that allows more intake/compression/power/exhaust. Then yes you will gain horsepower.

 

you will gain HP anywhere from 2 to 5 HP. Specially if you already have I/H/E.
But the most noticeable difference is in throttle response. It is much better.
I bore Honda throttle bodies to 4mm over the stock bore.
Here is a picture of one of the T/Bs after I was done.

 

did you bore it all the way even past the butterfly

 

Of course! otherwise what's the point of it!
I make new bigger butterflies out of brass.

 

whats the largest you have gone on a d series tb, if you havent done dseries what would be the biggest you could go on one???? and i take it you ported the manifold after doing it as well right...


[Modified by BoostedED9, 10:51 PM 12/30/2002]

 

As big as possible may not be better. From what I understand a larger TB will increase topend power but may decrease some lowend because the larger TB will decrease the air velocity. you'll probably make some good power, just don't go too much bigger.

 

get the manifold port matched and it ll make a lil difference

 

[QUOTE]you will gain HP anywhere from 2 to 5 HP. Specially if you already have I/H/E.
But the most noticeable difference is in throttle response. It is much better.
I bore Honda throttle bodies to 4mm over the stock bore.
how much do you charge for doing this?, and how big can you go with a gsr tb?

 

you need to be very careful before boring your own tb to somehting larger. if you have a 1.5L and throw a 62mm tbody on it you will kill all of your airflow and decrease performance. main reason is because the motor cannot produce enough vacume to move that much air.

 

I charge $125 including return shipping.
I bore ALL honda T/B's to 4 mm over the stock diameter at the butterfly.
Any bigger than that and you risk destroying the T/B.

I have done a whole bunch of them and I did mine to almost 6mm over the stock one, BUT I had to add material to the TB in order to make it work. That is something I am not willing to do to a customer's T/B.

 

What's the stock d-series TB bore? How does that compare to a b-series TB?

 

i was just going to ask that?

i have a 91 Si throttle body, how large is it and how much do you recomment boring it? I have a d16y7 with a PM6 ECU

 

The stock CRX Si T/B is 55 mm at the butterfly.
the JDM B16 T/B and the US B18b T/B are both 58mm.
The GSR and Civic Si are close to 60mm.

 

here is mine

 

Here's mine, BBK 70mm TB match ported to a skunk2 intake mani...I havent dynoed car yet but i noticed slight hesitation on accelaration on low rpm's (3.5-4.5K but quick from 6 to 9K, like you're on 2nd gear and I'm actually on 4th...

 

ok....
here's my problem!!
i'm swapping a d16y7 into my 90 civic dx, but i'm useing my factory intakemanifold..... that is my throttlebody right? will that work for me.... it's my work/sh$&z and giggles car. nothing special, but i'm trying to make it fairly quick w/o having to change out to an si harness.

 

I have a 75mm BBK tb mounted to my STr intake manifold.

But also my engine is fully built and has a big t4 turrbo. hehehe.

 

Not installed yet, but i'm running a y8 mani with 90 teg tb.. This should be a good gain since i'm running a cam..

 

I really don't think it would be worth it for a tiny little DPFI TB. I don't know exactly how big it is, but when you hold them side by side, it looks like about half of the Si TB's size. Plus, with the injectors mounted right on the TB, you may accually do more harm than good. Although it would be kind of fun if you could pull it off, It would blow people away if you beat them in a race and then open up the hood to reveal a DPFI.

 

first time i ever tried swaping my Z6 and didnt really worked going to OBDI way i swaped everything back and kept the DPFI for 2 days on the Z6... u wouldnt belive how bad and underpowered it is.... was even worse than the D15b1...

 

how much would it be to bore a 90-93 integra tb??? you would bore it to a 62 mm right? also do you provide bigger gaskets with them or what??? thx

 

well i'm swaping it to mpfi the same way a zc is swapped into a dx w/ a resistor box an 4 injectors!! so it won't be dpfi, but i'm keeping the same harness so that means dx intake manifold.... so would it be worth while?

 

in order to swap to mpfi, you need an mpfi intake manifold (as well as an mpfi ECU, Distributor, and resistor box) unless you plan on drilling holes into the dx manifold to mount the injectors