RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)
-   -   SP info (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/sp-info-283446/)

Brad88GXL 03-16-04 11:08 AM

SP info
 
I just blew my first engine and will probably get it rebuilt. quick question though, with a street port, are any fuel upgrades necessary to accomodate the extra air? or will it be fine as is? I currently have a 2 1/2" custom exhaust from the manifold back and will eventually replace it with the racing beat exhaust and I also have a K&N cone filter. are larger injectors/ s-afc required/recommended?
Car is an 88 GXL

scathcart 03-16-04 11:15 AM

No. You won't need more fuel.

Bukwild 03-16-04 11:40 AM

unless you want a half bridge. If you want to street port as far as you can go drop Kevin Landers a line at Rotary Resurrection. He can hook you up with what you need

YearsOfDecay 03-16-04 11:50 AM

A full exhaust on a second gen USUALLY makes them run richer on a stock engine..

I would have to agree that your not going to need more fuel with a street port.

Slap it on a dyno with a wide band to be sure (after you break in the new motor!!!)

scathcart 03-16-04 11:53 AM

1. He asked for street port info, not bridgeport info.
2. He has an N/A. Bridgeporting an N/A is very touchy with respect to intake and exhaust manifolds, and should generally not be touched unless some serious concentration will be focussed onto these.
3. Rotary Resurrection is out-of-the country for him. There are plenty of rebuilders close to him that can do a similar job for the same amount of money.

scathcart 03-16-04 11:54 AM


Originally posted by YearsOfDecay
Slap it on a dyno with a wide band to be sure (after you break in the new motor!!!)
I wouldn't bother unless you have some way of tuning for power.

N/A's on stock ECU's don't detonate, so why bother with a wideband run to check AFR's?

gray 87 fc 03-16-04 11:55 AM

i was wondering how many miles do you have to drive a freshly rebuilt/ modded rotary motor for because i know piston motors is around 1000 milesto break it in that is

scathcart 03-16-04 12:01 PM


Originally posted by gray 87 fc
i was wondering how many miles do you have to drive a freshly rebuilt/ modded rotary motor for because i know piston motors is around 1000 milesto break it in that is
Depends on the rebuild. Ask your rebuilder.

jon88se 03-16-04 12:03 PM

a full exhaust does not make any FC run richer...on a TII a full exhaust on an otherwise stock car will blow your motor pretty quickly as you'll constantly be hitting fuel cut. and on an NA I don't think the ECU adjusts the mixture at all since an exhaust only effects air being pumped out, not sucked in...the ECU doesn't see any additional air coming in through the AFM. that signal should remain the same if I'm not mistaken

Aaron Cake 03-16-04 03:42 PM


Originally posted by jon88se
a full exhaust does not make any FC run richer...on a TII a full exhaust on an otherwise stock car will blow your motor pretty quickly as you'll constantly be hitting fuel cut. and on an NA I don't think the ECU adjusts the mixture at all since an exhaust only effects air being pumped out, not sucked in...the ECU doesn't see any additional air coming in through the AFM. that signal should remain the same if I'm not mistaken
Oh dear, I'm not even sure where to begin on this post. It's basically 100% wrong...

The NA FC runs fairly rich from the factory. Any FC will benefit from the addition of an S-AFC to tune the fuel curve. This will hold true on a street ported engine as well.

88IntegraLS 03-16-04 08:01 PM

Some street ports even allow decent gas mileage! Power, economy, style, nice exhaust sound - all at the tip of your foot with a properly modded NA FC.


All times are GMT -5. The time now is 12:13 AM.


© 2024 MH Sub I, LLC dba Internet Brands