fc3s4utnv

Put in about 2 hours worth of dyno time today....



First couple of runs were 120's pretty solid with 110's tq...



By the time I finished it was 134hp and I cant remeber the tq, I forgot to get the sheets.



Engine is pretty dang well stock, the guy that built it just cleaned up the ports and put good RA seals and FD corners in it, no 5th and 6th ports, they are completely removed, RB header modified to a 3 inch collector, three inch pipe to the axle then splits into dual three inch tail pipes. Tunning was done by myself on an SAFC with a wideband, also made some passes on the squeeze.... cant remember the numbers but I will have the dyno sheets up on monday....

mazdaspeed7

Completely removing the 6 ports messed up the flow and actually hurts power everywhere. With just intake and full exhaust, I made 128 whp at 5000 rpm on my 90 GTU. I was getting terrible ignition breakup above 5k, and the power completely fell off.

fc3s4utnv

It seems to hurt the power down low, but up top I dont think it was hurting anything.

fc3s4utnv

Runs with and without the 50 shot....

Nateb123

Why remove the 5th and 6th ports? Weight savings? Because the system is pretty darn useful at cramming air into the engine for an application where you can't turn up the boost.

fc3s4utnv

I removed them when I put my built motor in, because the exhaust back pressure would no longer open them. I have wanted to do some of the things that I have seen to get them working again I just have not had the time to mess with it. Car runs great though I cannot complain, just kinda turdish below 4k in a high gear.

fc3s4utnv

I will be re tunning for the 150 shot on friday... borrowing a pair of slicks and taking it to the 1/8th mile, that is if it doesnt pop on the dyno...

j9fd3s

interesting what the no2 does...



imo 130rwhp is low, stock s4's will do 115-120rwhp

fc3s4utnv

The n20 woke it up alot, I had to pull the jets out to make sure it was a 50 shot.



But other than all of the ports just really being cleaned up it is stock, I am going to port match the manifolds and do a ported TB soon, we will see what that gets me.