nocab72

Rob @ Pineapple begins work on my engine this week.

I need to decide and call him with what stage port I want Monday.

I'm gonna try out the GT35/40 single setup and am looking for port advice from you pro's.

How much difference is there between a small street, large street and racing ports hp wise on the top end and how do each of them effect spool times?

I will probably abuse the engine bad enough that I plan to have a new engine rebuilt every other year so longevity really isn't an issue...

Thanks in advance!

K

Badog

Go ***** 2 da Wall!

the_glass_man

iTrader: (2)

Yes, Son stick your ***** in the wall!!!

relvinnian

Spool will almost always increase with a larger port, especially if the exhaust is ported heavily. Problem is not the turbo, but the engine itself. If the port timing is changed drastically so that large overlap occurs, then engine itself will not want to make power in the lower rpms. The turbo will be spooled, and the torque will increase proportional to that, but the VE% at the lower rpms will be less than it could be with less overlap. Up top is when the engine WANTS to shine with a larger port, but I BELIEVE the GT35/40 will be somewhat of a restriction. The exhaust housing is not large enough to support that kind of port in my opinion, and you'll end up with a lose lose situation. It will still make good power, but it will not be optimal. An engine that wants to make peak torque at 7200, may only be able to make it at 6700 rpm due to the built up engine backpressure on the top end. This may seem negligable, but it's not! A couple hundred rpm lift in the torque peak, and torque curve itself, can result in a large increase in power!

It really depends on the power you want, and where you want to make it, as well as how much boost you plan on running. In my opinion, unless using an EXTREMELY large turbo, lag is not a huge issue. If your combination is designed properly, and you know how to drive, you will have no problem keeping your engine in the meat of it's powerband. I personally would go with a secondary bridge port, and a t66 1.15 q-trim. If all the details of your combination are designed properly, you will see fairly good response. The 66mm compressor is very versatile, and has good efficiency both at low PRs, and up to 26/27psi. The bridge port combined with the large turbine housing will ensure you will have a BROAD powerband as well as the ability to force all that air from the 66 in on the top end and at high PRs. If you don't plan on running 26 psi ever, I would step down to a p-trim on the turbine.

PM me if I can help in any way

rx7passion

get the largest street port, the gt35/40 is a fast spooling turbo your only helping yourself out.

Mr. Stock

I wish I could tell you my experience since I have a Pineapple Racing motor with a street port and the GT3540 turbo. But my car is far from finished.
I am hoping to have it running in the next 4-6 weeks.

nocab72

with luck my turbo kit should be here next week and the engine the week of Sept 16, so it sounds like we may be wrapping it up about the same time...you planning to goto gordon's single BBQ?

K

Mr. Stock

If my car is up and running, I'll try my best to make it.