Kahren

iTrader: (13)

i am in process of puttign my ported engine back together, i was wondering how i can pass teh rev limiter and rev to 9k, i will get an afc to add or subtract fuel as necessary on the dyno.

i dont wanna go carb and i cant afforord a $1k standalone what do i do?

OC_

revlimiter? i havent found it yet if there is one. iv been to about 8.5 (racing)

Pinfield357

what model and year do you have?

Kahren

iTrader: (13)

91 NA type B

darkwaveboi

type b?

von

Type B lol

Hey yo...I shift at 8500rpms in my highly modified stock port. With the right mods and a streetport you WILL rev t0 9k....Put it on a dyno and see where your A/F ratio is at. Usually it will still be rich at that rpm and power with the stock 460cc inj. But just in case get a S-AFC and at the most you will need a T11 fuel pump..This might also stop pressure drops when the stock pump wheres out or whatever but im not sure about that stuff.

ebay7

You running a tii pump?

von

No But some streetport engines are making 200rwp and alot more...Im sure its possible that he might need a T11 fuel pump. They only put out a tad more anyways dont they...I my oppinion I dont think the injectors will go 50 pecent more fuel with the S-AFC because the pump will start maxing out. I dont know what the power level is but thats a guess. I do know that around 10points lean on the S-AFC accounts for 1.4 or so A/F mixture according to the dyno. At -12 points I go from 11.6/1 a/f to 13/1 or close to these figures ( I dont have the dyno chart with me at the moment) Right now its at 13.5-8 / 1 A/F and around -16-18 points on the S-AFC. I have this weird feeling like the T11 fuel pump puts you around 1. 3 or so points below stock ( or around 11.6 at certain rjpm) By the way im talking about 7.5k rpms here but its also rich throught the other rpms as well. My guess is that at pluss 10 I could be running around 200rwp because thats 40rwp than im making right now ( or a 20-25 percent increase in fuel) without a streetport or pump. Sorry for the mass confusion but thats were my answere came from...

dolemite85

I got a question. What is the redline of a streetported series 4 engine or how high can I rev it.

Rotorific

iTrader: (1)

In that case the redine is what ever you want it to be. The rev limiter or fuel cut of an S5 stock ported motor is 8800 where the s4 motor is 7800...i used to bounce off that **** once a day. For an S5 motor the power would probally fall off around 9k so i would shift at 9500 if you were to get the fuel cut disabled although there really is no way to do this without a stand alone.
-Gabe

Kahren

iTrader: (13)

i do remember going past 8k on a few occasions i just wasnt sure how much more i could go. i guess its 8800 like Rotorific mentioned. i wonder if there is a chip that i can install on teh stock ecu to get rid of teh redline/fuelcut

Liquid Anarchy

iTrader: (2)

...and what's a "type B"?

Jimmy325i

Depending on the ambient air temp, I run out of fuel delivery on the stock S4 pump shortly after 8K (seen as high as 8400rpm on a warm day) on a heavily ported motor. A/F guage shows I'm lean unless I bump up the hi throttle position correction to +4-5%. I'm waiting on the bigger injectors and the walbro before dynoing the car. I still can't supply enough fuel on the top end to get near 12:1. I think it ends up being somewhere in the 13.7- 13.2:1 range at the richest.

Kahren

iTrader: (13)

there were two models in 91 type a and type b, there were no more gtu and gxl, the type a was the regular "gtu" with powere steering manual windows and other stuff, the type b got leather seats and no cruise control, power windows, they are just diffrent packages.

Aaron Cake

iTrader: (1)

Uh huh....

I own an '86 base type R-Z-R-X-SI.

Seriously, why do you want to go past 8K? There's no reason to on the street, and if you're racing, you're going to have to do some internal engine modding to stay reliable at that RPM.

Kahren

iTrader: (13)

its ok to go past 8 i am not goign past 9k
and its not like i am gonna do that on daily basis

OC_

in stock config, it feels like my 90 GXL stops making power aronud 7.5....

is that bottleneck all in the airbox/mas air?

Kahren

iTrader: (13)

you shoudl feel that the power starts to die out at about 7-7.5k that is the limit for the stock port more then the intake or anythgin else

Project84

Ever see a clutch start to desintergrate and come through a floor board? If you race and your engine hangs out in the 9500+rpm range, you may want to invest in a scattershield. And what is the big deal with shifting at redline? I would dyno test my car and see where it makes torque and power and figure out where the most optimal shift points are from their.

Kahren

iTrader: (13)

on most small displacement cars u have to shift above redline to stay in the power band, that is why people go above the redline this is even more true with a NA car. you can calculate all u want it will all come down to goign to the track and testing it out and being surprised. if you dont belive me try it for yourself.

Jimmy325i

The clutch should stay together till about 12K without any risk of injury or destruction. Internals of the motor will be hashed long before then. (unless you're talking 2 piece e-shaft and lightened rotors)

Bridgeported

I'd like to see someone with a completely stock FC do some 1/4 mile runs shifting at 7500rpm redline, and 9000rpm. If they can nail the launches close enough, my bet would be the 7500rpm shifting would result in faster times. Like others said, on a stock RX-7, power is already dying down in the low 7k rpm range. If you shift at redline, you still end up being in the powerband, so why go higher?

On a modded engine though, it can be a benefit for sure!

Bambam7

WHAA????
OK, first off, I'm assuming you are using an A/F meter on the stock 02 sensor.. JUNK! You can't get to within 1 or 2 full points on the A/F ratio with a narrow band.

Second, if you are trying to tune to 12:1 at redline on a street ported motor, that's a huge waste. With a street port, you might want to see 12:1 at MOST around 3-4k, but at redline you are making the most power around 14:1.
I strongly doubt you will need the bigger injectors and/or TII pump. You also can't compare TII power with N/A power. If the two engines are both putting out 200 hp, the TII will use a lot more fuel, since it has to keep AF ratios down to prevent pre-ignition.
I was running a heavily modded N/A engine with a big street port, and I still had my S-AFC leaned out around 10% at redline, and it pulled strong to 9k.

BTW, with a street port, it's generally best to shift at 8.5k-9k, since the real power doesn't hit till at least 6k anyways.... so shifting up that high (as long as you are still making power) won't leave you on your face after a shift. Stock port... doubt it.

Jimmy325i

As luck would have it a good friend of mine has access to a climate controlled dyno at his school (tech college) and may be able to get my car in there for FREE in the next 8 weeks. We'll see what she does when hooked to the wideband and properly tuned for max power.

Right now I'm feeling the best pull when running more rich than stoich. The pump will not feed my engine to 9K. I have a brand new fuel filter in it so its not a clog causing the lean out. The butt dyno referenced by the a/f gauge (halmeter af30) is telling me a different story than for your car. Exhaust systems, intake porting and even filter choice, and actual engine porting are most likely entirely different so how one street port responed to a/f ratios will not likely be the same for another.

My motor also has the S5 TII intermediate housing. Not really the same beast as a normal S4 street port.

Liquid Anarchy

iTrader: (2)

Hey Jimbob...

What kind of fuel filter did you replace yours with?