LS1 Guys...What do you shift at/rev to?

[Bam]

My car is auto, and currently shifts at 5500rpm. Using previous knowledge and glancing around on ls1tech it seems that ls1s breathe more up top and lots of people are shifting between 6200-6500 on a basically stock or bolt on car.

 

Now I know from my dyno that peak hp is about 5500, so what would revving the car out to 6500 do for me? Wouldn't it be diminishing returns? I.E., you're hp/tq is decreasing as you increase your revs? Or is it a catch 22 because the car has to shift more times and I'm in a higher gear going through the traps that I may actually be suffering at the track?

 

I'm just trying to see what the general consensus was, and what everyone felt was a safe rpm to rev to.

[CRed05]

HP starts dropping after 5500rpm? That cant be right.

 

(Torque X RPM) / 5252 = Horsepower

[Bam]

HP starts dropping after 5500rpm? That cant be right.

 

Yeah, I mean unless I'm reading this graph wrong...it appears that MAX HP is at or just a hair under 5500rpm and MAX TQ is at or about 4500rpm.

 

I dunno much about the LS1 or dynos, I'm learning as we speak, but I guess I gathered from reading a bunch that these cars liked top end and revved higher than say a 5.0l mustang.

[Bam]

And this is probably a retarded question, because I'm pretty sure you can't, but can you 'move' the powerband with simply just tuning, or does it require actual parts. Like I know different cams offer power in different areas of the powerband, like low/mid/high etc, just didn't know if there was anything else involved.

[CRed05]

Think about it this way. Sport bikes make next to no torque, but they rev them really high to get horsepower out of them.

 

Your hp is probably dropping because thats when they took their foot off the gas.

[Bam]

HP starts dropping after 5500rpm? That cant be right.

 

(Torque X RPM) / 5252 = Horsepower

 

That equation doesn't work out to what my dyno graph shows...the one I have in front of me (I did multiple pulls) shows MAX POWER at 308.4 and MAX TORQUE at 327.3. The torque peaks somewhere between 3800-4500rpm, its hard to tell since its so flat with only a couple tiny bumps. And the HP peaks at about 5300, again hard to tell but only because the graph printer cut a small half inch section out/left blank.

 

But if I use that equation.... (327.3 x 3800) / 5252 = 236.8 HP

Or.... (327.3 x 4500) / 5252 = 280.4 HP

 

Both of those figures are lower than my peak HP of 308.4 on this graph, unless those figures are saying that's how much HP I have at that RPM?

[Bam]

Think about it this way. Sport bikes make next to no torque, but they rev them really high to get horsepower out of them.

 

Your hp is probably dropping because thats when they took their foot off the gas.

 

Hmm, so you're saying that if I took it back and re-dynoed it and pulled to say 6500rpms, the graph might show a different powerband?

 

That makes sense in theory, but my graph clearly shows the car going to 5800rpms and the car is already dropping hp and tq, unless it continued revving a few hundred more rpms after releasing the gas pedal?

[CRed05]

hat's how much HP I have at that RPM?

 

Correct

[wagner]

I have my car shifting at I think around 6k or so. When mine was set up I wanted to make sure it was very safe and within limits of the car's ability. I know I am leaving power and ET on the table but if it keeps the car healthy and off jackstands that is fine by me.

[CRed05]

That makes sense in theory

 

Also correct

 

In theory your engine will continue making HP the more you rev it. But your engine will run out of its efficiency range somewhere.

[Bam]

I have my car shifting at I think around 6k or so. When mine was set up I wanted to make sure it was very safe and within limits of the car's ability. I know I am leaving power and ET on the table but if it keeps the car healthy and off jackstands that is fine by me.

 

True, I very much want to keep the car together and not break anything, I just thought 5500rpm sounded low for an ls1.

 

Can you post your graph so I can compare it to mine?

[wagner]

True, I very much want to keep the car together and not break anything, I just thought 5500rpm sounded low for an ls1.

 

Can you post your graph so I can compare it to mine?

 

I don't even have my graph lol and I don't know if it would do much good due to my converter. After my car was tuned the only thing I was worried about was that car was healthy and ready for the track.

[Bam]

I don't even have my graph lol and I don't know if it would do much good due to my converter. After my car was tuned the only thing I was worried about was that car was healthy and ready for the track.

 

Aye, well it definitely ran well. I'm sure I'm splitting hairs, the car feels good and is hella fun, just curious I guess.

[smokinHawk1647545499]

i shift mine at 7000, redline at 7200 incase im a bit slow at the shift.

[99ta]

I shifted my bolt on car at about 5800. so realistically I was shifting at like 6, since our tachs are slow.

[Squale iii]

I shift at 6300-6500. Light is set to come on at 6300 so I have time to shift. If I had ARP rod bolts I'd go to 7 probably.

[Guest Removed]

randy sets them at 6500, when it shifts, it drops right back into the torque peak, which is what you what, cause thats when the hp starts to push the car

[Bam]

Thanks for the responses, have any/all of you guys had your car on a dyno to verify it's still making power that high?

 

Again, just curious.

[Bam]

randy sets them at 6500, when it shifts, it drops right back into the torque peak, which is what you what, cause thats when the hp starts to push the car

 

I would think that if my car shifts at 5500 and it makes peak tq around 4000, it would be dropping back down into that peak tq range, or very close. I haven't watch this car closely enough and its auto, but I do know that on previous manual cars if I shifted up a gear it would usually drop the RPM's down about 1000-1200rpms on average.

[Guest Removed]

Thanks for the responses, have any/all of you guys had your car on a dyno to verify it's still making power that high?

 

Again, just curious.

 

 

you cant compare the dyno's

 

 

http://i5.photobucket.com/albums/y196/gearhead559/red%20mess/before_after.jpg

 

stock 98, with a cam and ls6 intake.

 

but its a m6 car..not a auto

 

peaks at 6500!

when you shift, it drops right down around peak torque...

[Bam]

I'm not trying to compare dyno sheets, just asking for exactly what you posted, for people to verify that them holding higher revs is worthwhile for them.

 

Wonder what the cam did to change the powerband on that car you posted compared to a stock profile cam.

 

Thanks for posting it.

[Guest Removed]

well the dotted lines are cnc heads and cam..(not sure what cam to be honest) but stock heads and a fresh motor, with a ms3 cam is the solid lines

[MrMeanGreen]

How about next time you take my advice.

 

Your car is shifting too low anyways. Way too low.

[Bam]

How about next time you take my advice.

 

Your car is shifting too low anyways. Way too low.

 

How about I can't do anything about it now, so drop it? You've already PMed me your unhappiness fairly rudely, I'm not sure what Randy could have done that Brian didn't?

 

Can Randy magically make the car have a different power curve, or pull at a higher RPM? If so then maybe I'll go see him, but as of now I'm happy with how the car runs/drives, but as anyone who mods a car I'd like to see it go faster.

 

Unfortunately, everyone on LS1tech seems to think the car is perfectly inline for a lid only auto car, and I obviously have nothing to personally compare it to.

 

I chose to trust a friend of mine's advice over yours, so what? Not only that but randy didn't exactly give me a good vibe over the phone, and I feel Brian went out of his way to take care of me on the spot.

 

I guess what I don't understand is how ANY of this has anything to do with the tuner in this situation???? If my car is DROPPING power after 5400rpms, WHY should I shift higher? And how can a tuner fix that?

[Guest Removed]

How about next time you take my advice.

 

Your car is shifting too low anyways. Way too low.

 

 

needs more gear...

 

hell i think wag's car with some 3.42's radials and a ms3 cam and a 100 shot would move the fuck out. there are also better cams out there now, but it hards to beat whats been proven time and time again(if you want to talk cams, in a auto car..talk to v8beast, i think he has changed his 20 times now or so).but i know or do ls1's