learned something abt limiter

stealths13 · 08-19-2004, 12:47 AM

well being a noob here i read abt how the s13 ( mines is a 92) is rev limited at 7800 rpm ( or 7600 watever) and speed limited at 115.. but what i didnt know was that its not actually speed limited.. i tested the rpm i was at in 5th gear when i hit cut (115) and i was at 5500 rpm.. later i was on my drive way,,. put the car in 5th.. pushed the clutch in and revved it and guess what.. it didnt rev past 5500 rpm.. so what i learned is that the car is rev limited to 5500 rpm in 5th gear and that makes the car cut off at 115,,. i always thought there was a sensor and when the speedo hit 115 it cut off cause of that..
anyways just something i learned.. if u already knew this.. then disregard just thought i would share

peace
rick

KB240SR · 08-19-2004, 05:11 PM

I thought the redline on a DOHC S13 was at 7000 or something close to that. If your revving out to 7600 or 7800 then your probably getting valve float or something like that which wouldnt be limited. but for fifth gear there is a sensor on the tranny that all you have to do is disconnect it. ive got a SOHC S13 and did the auto to manual swap the only sensor i have plugged in is for the reverse lights. Im also running a automatic ECU so i have no rev limiters and no speed limiter. My redline is set at 6400 or 6500 and it revs to 7000 before it gets valve float or whatever its called. Anyway revving out that far isnt good for the motor.

DriftItLow · 08-19-2004, 05:18 PM

if your getting on it, press the clutch in twice real quick and then shift, in fourth i did and it works passed it

Xracer · 08-19-2004, 05:26 PM

the 91-94 KA24 for the S13 has a 7k redline (fact, i have one)

anyway when i get my car registered and have some fun with it all i have to do is unplug a sensor on the tranny to remove the speed/5th gear limit?

KB240SR · 08-19-2004, 05:45 PM

theres 4 sensor on the tranny. the first closest to the engine is the reverse sensor, the the second is the speed sensor which is actually bolted to the tranny, the third is something and the fourth is something. The fifth gear sensor is one of the last two farthest away from the engine. Im not sure which one it is but i have both of them disconnected right now.

stealths13 · 08-19-2004, 06:42 PM

well then i obviously dont have a rev limiter cause my car pulls to 7500 ( where i stop and shift ) with no prob.. prolly goes even more.. im ka right now and det in abt 1 months so i dont really care abt the enginebut is 7500 too much for stock ka? or even det?

i will try presssing the clutch in 2 times idea and see if it works.. i am also going to remove the speed limiter cause that sucks..
thanks for the replies guys

Rick

stealths13 · 08-19-2004, 06:47 PM

valve float
whats that.. i dont hear anything or feel anything strange when i rev to 7500 rpms
i also heard with an sr with thick head gasket and rocker arm stoppers u can rev to abt 8k without worries
correct me if i am wrong

KB240SR · 08-19-2004, 08:00 PM

im not saying your wrong or anything about when you shift but the redline is usually there as a warning to you that your pushing your internals more than needed. When going over Redline probably doesnt benifit acceleration any because of torque and horsepower dropping off after a certain point. Valve Float is when the valves stop moving in and out and adds more fuel to the motor than needed causing the motor to blow up. I think thats what it is. I could be confused with something else.

Sexual Banana · 08-19-2004, 08:58 PM

Valve float is when the motor is spinning so fast that the (stock) valve springs cant keep up with everything else, so the valves just stay open. Bad things happen.

Xracer · 08-19-2004, 10:02 PM

yea...the cams are spinning faster than the springs can keep up with. I definatly wouldnt reccoment revving the KA anything past 7k. im suprised it even has a redline up there with its long stroke.

UberMunkey · 08-19-2004, 10:14 PM

dude, the redline is there for a reason. keep disregarding it and you'll eventually be sans car.

the ka-de peaks hp at 5600 rpms anyway and torque about 1200 revs lower, so whats the point of beating your poor motor like that?

**240-kid** · 08-19-2004, 10:41 PM

^

:

**240-kid** · 08-19-2004, 10:45 PM

Well according to dori-san the limiters should be:
Redline: 6400rpm for SOHC and 6900rpm for DOHC

S13lover · 08-19-2004, 10:49 PM

My '91 cut off at 115 mph and I'm fairly sure the car haden't reached 5500 rpm yet. Maybe its just that the stock car reaches 115 mph in fifth gear at 5500 rpm.

**240-kid** · 08-19-2004, 11:01 PM

^ Nope what you hit was the speed limiter

110 speed limiter 5425 ro something rev limiter in fith 115 is Fuel cut

RalphCare · 08-20-2004, 02:42 AM

hmmm, ive never heard a KA at 7500. Anyone dare to take a video/sound clip :-)

if u guys are swapping soon, i see the point of beating the engine, but u could sell it to someone who needs it and take some cash off the swap price, without haveing to withold information of how u secretly beat the engine.

but then again everyone gets their SR without knowing how its been treated. so its all becoming understandable now.

anyways.. going to bed. gotta hit the junkyards for some s13 interior parts tomorrow to get my interior of my car (which i wont have for about 2 years) ready and all sexy and stuff. digital sweeping a pillar tach... Mmmmmm

KB240SR · 08-20-2004, 11:41 AM

I dont even take my SOHC to redline. I shift right before 6k. Id like to prolong life on the motor for when i make it turbo this spring.

uno · 08-20-2004, 11:59 AM

shift between 6 and 6500 don't go past it...not good for your motor and also doesn't benefit when you could already be shifted and back in the power band....so you're actually going slower shifting at 7

skribbble · 08-20-2004, 12:04 PM

So thats why ive hit 140mph in 4th gear in my friends car lol

stealths13 · 08-20-2004, 01:42 PM

shift between 6 and 6500 don't go past it...not good for your motor and also doesn't benefit when you could already be shifted and back in the power band....so you're actually going slower shifting at 7

ok so u mean to tell me gearing doesnt come into play? ur statement is true if all the gear ratios are the same.. but in the world i live in its not.. shifting fromt 4-5th at 5500 rpms will be slower than shifting at 7k

anyways i didnt know the redline was 7 thats why i asked.// my g20 with the sr in it had a redline from factory of 7800 rpm so i thought maybe this did too

whats and acceptable place to shift on an sr with thick Hgasket and arp headbolts?
Thanks for the replies guys
Rick

uno · 08-20-2004, 01:46 PM

Quote:

Originally Posted by stealths13

shift between 6 and 6500 don't go past it...not good for your motor and also doesn't benefit when you could already be shifted and back in the power band....so you're actually going slower shifting at 7

ok so u mean to tell me gearing doesnt come into play? ur statement is true if all the gear ratios are the same.. but in the world i live in its not.. shifting fromt 4-5th at 5500 rpms will be slower than shifting at 7k

anyways i didnt know the redline was 7 thats why i asked.// my g20 with the sr in it had a redline from factory of 7800 rpm so i thought maybe this did too

whats and acceptable place to shift on an sr with thick Hgasket and arp headbolts?
Thanks for the replies guys
Rick

you won't hit 7 grand in 4th if you still have the speed limiter..you'll hit the cut....so go back to your world....it sounds cooler than the real world....I go to the strip almost every friday so i think i might know a thing or two about "real" world shifting.....and i said 6500 not 5500 btw....

EDIT: Yes gearing does come into play alot, but you didn't say anything about changing the gearing...so that point is not valid in this

Also my posts are in regards to KA's with stock gearing....i am no sr expert by any means...so i cannot answer those questions...no actual experience with them...

driftinS13 · 08-20-2004, 02:09 PM

i dont go anywhere in my car after 5500....the only thing that keeps me moving is the momentum of the car...so i learned to shift at 5000 and enjoy 30 mpg.

edit: but the k&n filter sounds so mean at around 6500

stealths13 · 08-20-2004, 06:37 PM

EDIT: Yes gearing does come into play alot, but you didn't say anything about changing the gearing...so that point is not valid in this Also my posts are in regards to KA's with stock gearing....i am no sr expert by any means...so i cannot answer those questions...no actual experience with them...

well anyways i didnt mean any offense bud.. thanks for taking the time to educate me
Peace
Rick
p.s im ordering some gram lights for my car

s13goingsnail · 08-21-2004, 12:52 PM

my car doesnt have a limiter on it anymore, i pulled the speed sensor wire out of the ecu, then i unplugged the speed sensors on the transmission, so no limiter, because the speed sensors on the tranny feed the tach then feed the computer to shut of ignition at 6500 rpms in 4th (115 mph) and 5500 (155mph) in 5th, so because the instrument cluster never sees how fast the transmission is spinning the computer doesnt cut the ignition.

on a side note i hooked up a switch to the clutch pedal and wired it into the 5th gear sensor and wired that into another switch to make a homemade launch control, works perfect and far cheaper then msd s version which does the same thing.

uno · 08-21-2004, 01:16 PM

Quote:

Originally Posted by stealths13

EDIT: Yes gearing does come into play alot, but you didn't say anything about changing the gearing...so that point is not valid in this Also my posts are in regards to KA's with stock gearing....i am no sr expert by any means...so i cannot answer those questions...no actual experience with them...

well anyways i didnt mean any offense bud.. thanks for taking the time to educate me
Peace
Rick
p.s im ordering some gram lights for my car

That's cool...no offense taken, unless you really get the gram lights then i'll be jealous lol which ones you plannin on gettin? gram lights are my favorite rims, i'm gonna get the gold six spoke ones one day hopefully..