brenth

Hey guys

I have a 1997 Integra Type R Race car which I race here in New Zealand (we have a series called Honda Cup). Here's a pic of the car for reference:








(minus the MSD gear, threw that in the bin haha)

At the moment the car has the following:

-2.5" custom exhaust system (1 middle reso to oval rear muffler)
-3" SRI with Blox velocity stack and filter
-Feels 4-2-1 header
-Running obd1 chipped ecu with Crome

With this setup it made 140.5kw at the wheels (189hp)

Now im pulling the head off for a freshen up soon which will comprise of new valve stem seals, valve re-seat, and a few other seals etc.
The other day I started reading up on 3" exhausts that you guys are using on near stock b-series engines, and this got me thinking;

On my near stock application would I see gains in a 3" exhaust? Am I likely to lose any torque or power anywhere in the rev range?

I was thinking after the 2.5" header collector have an expansion adapter (2.5"-3") to 3" piping and then run 1 centre reso to a 3" magnaflow rear muffler. Sound ok? Or should i get the exapnsion adapter on the header collector and run a 3" flange there?

I have also seen people playing around with different intake diameters and lengths, is there a general rule here or more about making a few different lengths/diameters and testing them on a dyno?

What about throttle body's? Spoon taper bore the way to go? At the moment im just using the oem ITR one.

I have also purchased some Buddyclub cam gears, a hondata intake manifold gasket so these will go on at the same time as the head freshen up.

Thanks in advance for you opinions/recommendations

95skunkedgsr

taper bore is the way to go on tbody there are cheapers options then spoon , as for the exh the 2.5 collector will be fine but i would do 3inch all the way back after that

brenth

Thanks for your reply mate.

What other options are there in terms of a taper bore TB? Get my ITR one bored the same as the spoon one?

Sweet 3" looks like the way to go then, any difference in sound when comparing mild vs stainless?

Any comments on regards to intake?

95skunkedgsr

sound wise i dont think there is a huge differnce but there could be a slight diff, I cant put it in technical terms for it, and yea you can your stock itr tapperd or if your looking for bolt on there acouple companys that make them

95skunkedgsr

on the intake side im not 100% sure but when your trying to tune lenght i heard of acouple way to do it. One is to put the longest pipe you can fit on there. then take a inche to 2 inches off at a time on the dyno and see where it switches the power around, and i guess you would do the same with 2 differnt pipe diamiters also , sounds very time consuming. dont take my word for it i could be wrong , there is a caculation somewhere to figure out where you should start for it tho

95skunkedgsr

you would probly make a few more ponies playing with adjustable cam gears then trying to figure out what the best lenght would be for the intake

95skunkedgsr

for ***** and giggles if you can add about 3 inches to your intake on the dyno and see what happins it might gain it might drop

brenth

Sweet cheers mate, 3" exhaust definitely looks like the go.

Not many people (if any) have tried a 3" exhaust on a near standard b-series here in New Zealand so it will be interesting to see how it goes.

Taper bore TB will also happen, and will play around with intake length/diameter, however may just stick with the 3" and go with that, we'll see!

Thanks for the help

00Red_SiR

You should see some decent gains with a 3" intake tube around the 30"-33" total length range (or close to this as every motor is different). The 3" exhaust is the way to go but it will be louder if only running a muffler and no cat or resonator.

brenth

Wow that's a long intake, no way you'd be able to fit that in there. The 3" pipe in there at the moment would only be like 15" at the most and the filter is nearly touching the edge of the engine bay!! How do people fit an intake in that long? Go down into the bumper like a CAI?

I'm also going to cut up the headlight and use that to feed the intake air!

With the 3" exhaust I think I will run one centre resonator to a 3" magnaflow muffler at the end. I don't mind noise, but have already had a Buddyclub spec 2 system and that was just stupid loud, see below (can still hear the car 1/4 mile away from the camera haha):

http://www.youtube.com/watch?v=SJaLkm-nQ2E

brenth

OK bumping this up guys.

There had been a bit of discussion lately about exhaust noise at some of our NZ circuits. There has always been a 95db limit imposed but it has never really been an issue up until now.
More and more people are starting to complain about the noise (not racers or spectators of course haha) and the council has started taking measurements at the track and giving people warnings and then sending them home etc.

This brings me to my next question:

Is it possible to have a 3" exhaust system on an NA B series engine that is under 95db (at full noise measured maybe 15m away)? The council were taking measurements about 15m away from a section on the back straight where all the cars are doing high rpm at WOT.

Thanks in advance!

96dxB16

I'm running a 22" long resonator on my 3" exhaust along with a chambered magnaflow muffler. I passed sound at Infineon raceway, but not sure they activley measure it or not. They require 103db at 50ft. I feel like my intake makes more noise than my exhaust.

brenth

50ft is just more than 15 metres so that's a bit concerning. 103db limit would be nice, wouldn't be hard at all to be under that.

Stupid people who move into an area near the racetrack and then complain about it being too loud just for financial benefit.....

96dxB16

Yup, Laguna Seca is that way. It has a 92db limit. I haven't taken the car there since I installed my 3" exhaust though.

Seriously, I think you would pass sound if you baffle the intake. So much more noise comes from the intake over the exhaust. Another option people do is make a turn down (90 degrees) on the tail pipe to face away from the sound tower at a given track.

tempsohc

what spark plug wires are those?

brenth

They are Eagle 10.5mm leads. Made in Australia I believe.

I now have the same ones but in black: