ok i guess the best way to ask this would be to use my car as an example.

i have an 88 TII and i want to know if redline has increased with the mods i have done .


i have:
alum. 12 lb. flywheel
safc
jacobs ign. (rotarymaster)
full rb exhaust (3 in.)
bov
intake (cone)
fcd
rp comp. fuel pump

this is on a stock 88 TII motor. i want to better understand how does redline increase. i know with porting it increases but is that the only way.

 

You might make more top-end power...BUT the stock internals of the engine cannot take the high-revs for long. If you want to increase your redline you'll need to rebuild the engine with lightened/clearenced rotors and hardened stationary gears.

You'll be able to hit 10K all day with an engine built like that...

 

your redline does not raise with mods, your Peak power however does, your rb exhaust and intake would be the only things that make the power peak go up, stock power peak of 88TII is 6500rpm, with the exhaust and intake your peak power is probably between 7000&7500rpm, rev limiter kicks in at 7600rpm, so just shift at the rev limiter=7600rpm, if you feel the power fall off any, which is very easy to determine, then shift a bit lower until you feel your in the best possible power range, i will say your peak power is at 7200rpm and it wont fall off enuff to notice by 7600rpm, so you should be fine

and people say the 86-88 engines cant rev too high, i wouldnt have any 2nd thoughts about running one @8500rpm, thats where the stock tranny and stuff start to get unstable, the engine no, but the tranny parts on 86-88 wont doo much over 8500

hope that helps

 

so your saying it is safe for me to shift past redline and most of my power will be past redline. str8, the other day i was boostin pretty hard on second. i was trying to show my pops who has a 3rd gen. that my car can boost 10 to 12 psi now with my fcd installed. the beep came on telling me to shift but i ignored it trying to make the boost gauge hit 12 psi. i shifted around 10 psi a few seconds after the beep. he said i should be careful about passing redline but the car felt fine. would it be safe to run it like that again to see if the power falls off. i cant remember if it fell off any as i was trying to pay attention to the car in front of me which was coming up pretty fast, lol and my boost gauge. this is good stuff to know thanks bro!

 

I bet anything past redline at 10+ psi you are going to go way lean. the stock fuel system isn't going to keep up.

 

my car is running very rich, i have to lean it out actually. only on the low map with my safc and in the low rpms only. but when i run it hard it is always rich. i dont know if it was like that before i put the aftermarket fuel pump and air/fuel gauge. but with the mods i have on now it feels very capable of pulling 12 psi. im thinking of getting some 720 secondaries when i get my front mount and 90 gtx turbo upgraded with a to4 compressor, ZOOM, ZOOM!!!!!!!!!!!!!!!! of couse with a new motor--street ported and built by pettit, yeah baby!!!!!!

 

The way to determine proper shift points is to shift at an RPM that allows the RPM to fall on the torque peak after the shift is made. Maximum acceleration is produced at peak torque (throw the HP number out the door on this one). Using this approach shift points will likely be different for all gears and short shifting below the redline is common for the 2-3, 3-4 shift. Over-revving the motor is doing nothing but putting wear and tear on expensive parts.

A turbo car will also produce peak HP at a lower RPM than the NAs due to the resonance frequency of the intake. I can't think of a reason to rev a turbo past 8k. My TII's power fell off noticeably before redline.

Who's revving their stock shortblock past 8500RPM regularly? Not afraid of 10k? Tell that to the 200lb pile of scrap metal in the corner of my garage! Blew an apex seal on a short 8500RPM blast at an autocross two weeks ago. I thought revving it out would be quicker than shifting up a gear and then back. The apex seal didn't like it. From now on I'll take advice from the Racing Beat catalog and "never" exceed 8500RPM with stock apex seals.

Chris

 

crap man.. my '92 Civic EX ran 9500 RPM and is still kicking right along.. 7200 RPM redline on it. Raptor13x (dumb) shifted from 5th to 2nd while driving it @ 75 mph.

 

That was once, and only for a split second. Consistantly exceeding the redline on any engine will rapidly kill it, either through massive wear or a component simply failing due to experiencing forces beyond it's strength limits.
Also, stock cast iron flywheels aren't safe much past redline. And and over-revved engine failing isn't nearly as spectacular (or dangerous) as a flywheel letting go...

 

if you want to increase your redline you have to better your cars lubrication system and lighten the rotating mass. with hardened stationary gears, 3 window bearings and deepened oil grooves plus a bette oil system, you can hit 10.5K i believe. not to mention fuel and air to sustain correct ratios at that speed, but past that your ecc shaft will start to warp. i believe you can get it drilled for oil and weight, then you can get lightened rotors (clearanced too) evntually it is possible to hit over 13K but by thi time you will haveblown your transmisson, clutch, and flywheel all over the place.

but yo prolly wouldnt make much power after 13K anyways. the biggest advantage in internals (rpm-wise) would be if aluminum rotors were a possibility. that would probably allow 11-12K with just the oil mods and bearing mods.

Justin