Shifting at 6800 on STOCK heads!?!?
Thread Starter
Joined: Nov 2001
Posts: 1,711
Likes: 6
From: Lawrenceville, Ga
Shifting at 6800 on STOCK heads!?!? Isn't that a little extreme?
The car is a 98 SS M6 with a Vortech blower, bolt-ons and a completely stock motor internally with custom tuning.
The car is a 98 SS M6 with a Vortech blower, bolt-ons and a completely stock motor internally with custom tuning.
Re: Shifting at 6800 on STOCK heads!?!? Hmm, would you really ever need to rev a supercharged motor that high? <img src="images/icons/confused.gif" border="0"> Either way, that is very high to be revving on the stock valvetrain, I wouldn't make a habit out of it.
Re: Shifting at 6800 on STOCK heads!?!? You should not have to rev that high.. what does your dyno say your peak is.. I would shift at 200rpm higher than your peak and thats it...
Staging Lane
Joined: Nov 2001
Posts: 87
Likes: 0
From: MI
Re: Shifting at 6800 on STOCK heads!?!? Stupid without valvetrain modifications... you trying to destroy your motor?
And why the hell would anyone want to rev that high past your peak power?
Kinda like those musclecar guys saying.. yeah i can rev it to 7200rpm.. its fast..
Yeah that .420 .420 196/198 116ls cam really doesnt peak at 4600rpm itl rev to 7200..
<img src="images/icons/rolleyes.gif" border="0">
And why the hell would anyone want to rev that high past your peak power?
Kinda like those musclecar guys saying.. yeah i can rev it to 7200rpm.. its fast..
Yeah that .420 .420 196/198 116ls cam really doesnt peak at 4600rpm itl rev to 7200..
<img src="images/icons/rolleyes.gif" border="0">
Thread Starter
Joined: Nov 2001
Posts: 1,711
Likes: 6
From: Lawrenceville, Ga
Re: Shifting at 6800 on STOCK heads!?!? The car isn't mine it's my friends car. He said his power peaked at 6500, but I haven't seen the dyno sheet yet. I just thought that was too high for those crappy valvesprings, but I wanted some second opinions. Thanks!
TECH Enthusiast
Joined: Nov 2001
Posts: 652
Likes: 0
From: Newport Coast, Ca
Re: Shifting at 6800 on STOCK heads!?!? With STOCK internals and the blower, wouldn't his peak power stay right around where the stock rev limiter? (6250) I cant see how a vortech blower would help wind that car all the way up to 6800rpms. I just can't understand why he wants to shift it that high if he has the stock cam AS well as stock internals. anyhow, not a good idea to do.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Staging Lane
Joined: Jan 2002
Posts: 70
Likes: 0
Re: Shifting at 6800 on STOCK heads!?!? Not really...... superchargers and turbos just tend to enhance the power curve, not alter peak pionts! His peak power should be within 100-200 rpm of his peak power before the blower.
Not wise to rev the engine that high..... He is getting into some serious valve float and lifter pump-up at those rpm's.
Not wise to rev the engine that high..... He is getting into some serious valve float and lifter pump-up at those rpm's.
Launching!
Joined: Dec 2001
Posts: 204
Likes: 0
From: Salem, NH
Re: Shifting at 6800 on STOCK heads!?!? I second that the s/c'er enhances the stock power curve, that is atleast how it is with most other motors. Blower or no blower, stock valve train...6800 rpms <img src="gr_eek2.gif" border="0"> <img src="graemlins/gr_guns.gif" border="0" alt="[guns]" /> motor
[ February 10, 2002: Message edited by: brendon ]</p>
[ February 10, 2002: Message edited by: brendon ]</p>
Re: Shifting at 6800 on STOCK heads!?!? The blower motor will always make more power at a higher RPM unless you pass the peak efficency of the blower itself or run in to some other RPM related problem (valve control, port stall, etc). The output is directly related to the boost and the boost is directly related to the RPM. The higher the RPM, the more boost, the more power.
Re: Shifting at 6800 on STOCK heads!?!? Motor's gonna go like Hiroshima <img src="graemlins/gr_judge.gif" border="0" alt="[judgement]" />
Wish I could be there to see/hear it though <img src="graemlins/gr_devil.gif" border="0" alt="[devil]" />
Wish I could be there to see/hear it though <img src="graemlins/gr_devil.gif" border="0" alt="[devil]" />
TECH Regular
Joined: Jan 2002
Posts: 400
Likes: 0
From: Lincoln Park Mi
Re: Shifting at 6800 on STOCK heads!?!? I agree with Terry, at least with centrifugal chargers.
My buddy has a 98 SS with a powerdyne 6# blower. He has dynoed MANY times trying to work out the tuning. Even before he upgraded to the Hotcam the Hp curves were ALWAYS going up strong when the dyno was shutdown at about 6100. this was the firstthing I noticed when looking at the dyno.
My buddy has a 98 SS with a powerdyne 6# blower. He has dynoed MANY times trying to work out the tuning. Even before he upgraded to the Hotcam the Hp curves were ALWAYS going up strong when the dyno was shutdown at about 6100. this was the firstthing I noticed when looking at the dyno.
Thread Starter
Joined: Nov 2001
Posts: 1,711
Likes: 6
From: Lawrenceville, Ga
Re: Shifting at 6800 on STOCK heads!?!? It is internally bone stock!!! I'll have to see this dyno sheet for myself I guess. Maybe he was mistaken about peak power. But he does take it up that high for some reason <img src="images/icons/rolleyes.gif" border="0">
Hopefully I can convince him to quit before his motor goes ka-boooooom <img src="gr_sad.gif" border="0">
Hopefully I can convince him to quit before his motor goes ka-boooooom <img src="gr_sad.gif" border="0">
TECH Senior Member
Joined: Nov 2001
Posts: 10,341
Likes: 1
Re: Shifting at 6800 on STOCK heads!?!? He is going to toast that motor revving that high.
Boost has a negative effect on spring pressure, he is definitely going to float the valves and hurt something.
Chris
Boost has a negative effect on spring pressure, he is definitely going to float the valves and hurt something.
Chris
TECH Apprentice
Joined: Nov 2001
Posts: 339
Likes: 0
From: Indianapolis, IN
Re: Shifting at 6800 on STOCK heads!?!? I had the same problem with nitrous. it was real hard on the stock springs to where I would get valve float easy even NA. switched to 941s and it helped dramatically