MAX RPM before Rev Limit

[Paladin06Greg]

Just curious what your max RPM is before your car hits Rev Limit? Although you may not believe it, with several switch adjustments to my MSD-4 I get 7200. Tested and proven.. It might go higher but I've not tried it yet. OK, I'm waiting to hear that my ECU won't allow that.

[SC V6]

redline at 6200... I've got my MSD set to 6500.. couldn't tell u

[JoeB]

Greg, that's very interesting! Our red-line is 6,200 or 6,250? I know I've recorded 6,400 on my data logging equipment. I've been wanting take the RPMs higher after building the engine but I thought that was only controlled by the ECU. How do you do it and what box is it I need to buy? Have you talked to Carlos about high high you can go safely? -JoeB

[Alex(AUS)]

Standard, the car redlines at 6250 and cuts-out at 6500.

I dont see why you would want to rev a engine such as ours so high when the supercharger makes 100% of its torque between 3000 and 5000 rpm ... after this you are just making noise and causing damage. It is best to shift around 5500-5750. If you can infact hold the torque for that long this would be awesome ...

Alex

[DatSRBoi]

Standard, the car redlines at 6250 and cuts-out at 6500.

I dont see why you would want to rev a engine such as ours so high when the supercharger makes 100% of its torque between 3000 and 5000 rpm ... after this you are just making noise and causing damage. It is best to shift around 5500-5750. If you can infact hold the torque for that long this would be awesome ...

Alex

All the power is there, but early shifting isnt good when you want to give your all out performance, Early shifting means the engine dropping its rpm too low and would have to work its way back up again. So going redline then shifting puts the car in high power still and doesnt loose on its timing.

[Alex(AUS)]

Not really. Consider this scenario.

When you go from second to third in a manual version if you shift at redline you go back to 4krpm in third (at around 60mph). However by redline you have dropped a significant amount of torque (going on Eric's dyno chart you drop 40ft lbs atw from 5krpm to redline). But if you shift at 5.5krpm you will lose 20ft lbs combined ... ie 10ft lbs from 5 - 5.5krpm and 10ft lbs from 3750 to 4000 rpm).

So there you have it ... even for eric @ 290+ whp ... not a good idea.

I hope that makes sense.

Alex

[DatSRBoi]

Eh if Im correct you also have to know tq is checked off once you hit certain speed. Like highway racing, tq still plays a very important role but once its past its line hp plays the game of who wins and if the rpm drops too much then hp has to be rebuilted. Something like that. I think I worded it wrong but yea. Tq is important only to an extent. Look at track racing, you dont see guys shifting at like peak tq line, they go to redline to get best performance(most cases). So get me if Im wrong. Just what I was taught from racing classes Ive been to with my friend.

[Alex(AUS)]

I am confused with what you said about torque.

I donno ... best way to prove it one way or another is to try it.

Alex

[DatSRBoi]

I have tried it before. If you want best performance (majority of the time. Special occasion its different.) you go red line.

[Paladin06Greg]

JoeB, I have spoke with Carlos through Belen and he said it is no problem at all. As a matter of fact he wants to see the car and run some test. Believe me when it shifts at 7200 it is pulling like a beast..

Greg, that's very interesting! Our red-line is 6,200 or 6,250? I know I've recorded 6,400 on my data logging equipment. I've been wanting take the RPMs higher after building the engine but I thought that was only controlled by the ECU. How do you do it and what box is it I need to buy? Have you talked to Carlos about high high you can go safely? -JoeB

[Alex(AUS)]

Greg, what you are saying makes me nervous. Are you sure it is ok to be revving that high? You know, many other things (apart from pistons) are affected by this. Are the affected stock parts able to cope with this load?

However, as I said before ... if you are safely holding the torque to 7200 rpm (or close to) this is just an awesome job.

Do you have warranty on your engine form Arieta (sp?) (@ 7200rpm)?

Alex

[JoeB]

Alex, I don't know a lot about the implications of the torque curve. I thought that the max torque would always be at the same RPM. That would mean everybody would shift at the same RPM. My understanding is the shift point is determined more by the hp curve with the torque curve taken into consideration. If you look at every dyno sheet from our car, the max hp is always at the end of the run. When the dyno is stopped, the hp is still climbing rapidly. That isn't uncommon either. That is the way many high-performance cars get extra power is by raising the red-line/shift points. I just didn't think our ECU would allow it.

Greg, can you give us more info on how this is done and what MSD part is used, how it controls it?

I know the valves can be an issue when raising the RPMs so you need stiffer valve springs. Does anybody else know anything about what to be careful of doing this? -JoeB

[DatSRBoi]

I would like to know too bro. I want mo-power

[Paladin06Greg]

I have a MSD DIS-4. It requires two adapters that MSD will provide. There is a switch in the SW1 set, there is also a SW2 and SW3 set, that allows you to extend your Rev limit. Although the book that came with the MSD indicated extending your RPM beyond the ECU set rev limit may not work in all cases, mine does.

Also know that my ECU has been modified by JetChip.

[DatSRBoi]

I have a MSD DIS-4. It requires two adapters that MSD will provide. There is a switch in the SW1 set, there is also a SW2 and SW3 set, that allows you to extend your Rev limit. Although the book that came with the MSD indicated extending your RPM beyond the ECU set rev limit may not work in all cases, mine does.

Also know that my ECU has been modified by JetChip.

Dang you.. So what does it take to beat you?