RPM Red Line Question???

[G35turbo]

Ok

I know you can buy some ECUs that will move your red line. My question is how far and safe can u go with moving the red line without hurting anything and be totaly safe. Or is the stock red line the safest? I also looking to buy ECU and i dont have 1500 to spend On ecu and i was wondering if there is cheaper one that works well and its not 1500 bucks. Also when is the perfect time to change ECU. Right now my car I got Downpipe, intake, boost controller 14psi, BOV, Turbo timer, etc. Is it to early to change my ECU or it dosent matter when you change your ECU?
My cousin has 300ZX twin turbo and he changed his ecu and his ecu change the psi from stock to 14psi. I was wondering the ECU that are for are cars can do the same thing or not. and ohh ya his was only about 400bucks. Why is so much price difference between his ECU and are ECU?

[Twizted_3KGT]

holy crap enough questions? lol...I can answer one of them, the stock redline is your safest limit unless you have done internal work on your engine. If you go past that and you haven't upgraded your internals you'll get things like valve float and that's not a good thing to have.

[Stealthee]

There are not any aftermarket ECU's for our cars unless you get a standalone like AEM, link, etc.

[talskinyguy]

so far both answers are wrong.

Safe RPM on the stock engine is around 8500 rpm, i set my rev limiter on my AEM to 8300. For aftermarket ECU's you can get the one from dynamic racing that advances timing slightly and sets the rev limiter higher or removes it completely. Turbo BOB from 3si also does ECU work and has one with a 8000 rpm limit.

[xXxRocker5150]

Hey talskinny, I thought some1 said a while back that they had their 3000GT on a dyno chart, and after about 6500 RPMS the car starts losing power, so that's where u should set a shift timer thingy at if you get one... true or what?>

[mike93vr4]

doest that have to do with our turbos?

[Musashi3000GT]

Originally Posted by xXxRocker5150

Hey talskinny, I thought some1 said a while back that they had their 3000GT on a dyno chart, and after about 6500 RPMS the car starts losing power, so that's where u should set a shift timer thingy at if you get one... true or what?>

That was me rocker ol buddy. when I dynoed my car bone stock the dyno chart showed a power curve drop around 6500. which means my peak hp was at 6500 then it held slightly to 6700 and dropped at 7000 rpms, so I set my shift light to 6500. but 1. I have a N/A not a TT and 2. most racers will hold to 7000 rpms before shifting because when the next gear picks up it clips at a higher rev then if you shift at 6500 therefore you make up for the slight drop by kicking in the next gear a bit higher. I just dont like to redline cause i am parinoid and I really have never needed to in all the races I've been in. hell I usually shift at 6000 and havent had a close call to date.

[talskinyguy]

The power drop is atributed mainly to our turbos, but the intake manifold and cams play a roll in that also. I have 14b's so they flow a lot more air than the stock turbos. Also shifting when your engine stops gaining power isnt the best way of doing it

Example
This is very simplified to get the point across
Lets say you make
100hp @ 4000rpm
150hp @ 4500rpm
200hp @ 5000rpm
250hp @ 5500rpm
300hp @ 6000rpm
250hp @ 6500rpm
200hp @ 7000rpm

Now lets say gearing drops you 2000rpm when you shift. If you shift at peak power you go from 6000rpm to 4000rpm and 300hp to 100hp. This will feel faster because when you shift it will put you closer to the peak torque and you will then again be gaining hp all the way until you shift again. However if you shift at 7000rpm you only drop to 5000rpm and your power never drops below 200hp.

[Twizted_3KGT]

So safe RPM is 8500 for a 6g72? where do you get that kind of information at? Or did you just test it yourself?

[talskinyguy]

Not safe, that is the "max", "safe" is 8300. Matt at DR tested the heads to see when they float the valves, it happens above 8500rpm. All of his cars are on the stock bottom end and generally stock valve springs and lifters.

[Twizted_3KGT]

oh cool, I take it that's the same Matt that ran the 10 sec 1/4?

[talskinyguy]

the many 10 sec 1/4's

[6g72tt]

i saw a MINE'S ecu for the 6g72t engine in ebay did MINE'S make ecu's for our cars?

[BB1970]

Originally Posted by talskinyguy

The power drop is atributed mainly to our turbos, but the intake manifold and cams play a roll in that also. I have 14b's so they flow a lot more air than the stock turbos. Also shifting when your engine stops gaining power isnt the best way of doing it

Example
This is very simplified to get the point across
Lets say you make
100hp @ 4000rpm
150hp @ 4500rpm
200hp @ 5000rpm
250hp @ 5500rpm
300hp @ 6000rpm
250hp @ 6500rpm
200hp @ 7000rpm

Now lets say gearing drops you 2000rpm when you shift. If you shift at peak power you go from 6000rpm to 4000rpm and 300hp to 100hp. This will feel faster because when you shift it will put you closer to the peak torque and you will then again be gaining hp all the way until you shift again. However if you shift at 7000rpm you only drop to 5000rpm and your power never drops below 200hp.

im glad this has come up as last year i ran a 13.94 on stock turbos at 14psi on a cold surface.
never running a car on the 1/4 track i realised i could complete it in 3rd gear but was pushing it to redline.if this is the case, could my time been slightly quicker if i had shifted into 4th for the last 50-100 yards? as i noticed a difference on my 0-60ft times if i shifted from 1st to 2nd to 3rd at 6000rpms rather than 7000rpms.i just felt i would lose extra time shifting from 3rd to 4th for that short distance could make my times worse rather than better.