higher redline?

[Kraftsman]

I recently installed a new shortblock with a forged rotating assembly and a Roush TVS 2300. To get to the point I am sure this rased my redline, but I am also running completely stock heads (which is my project for next winter), so would this still raise my redline or not, and if so to what? Thanks for help.

 

[BSell]

I figure the better question is what engine speed do I 'need' to run. This is usually dictated by the intended usage.

Consider the rear axle, tranny, and engine combo as a set unit. They all must be tuned together for maximum performance.

Usually, folks who stay N/A push the upper end of the rev limit as engines of the same displacement have the opportunity to make more power when spun faster due to more power pulses (i.e. fuel run burned) in the same time period. Can you say Formula 1?

All of this faster spinning around makes for hella high forces within the parts, which requires stronger and stronger parts.

If you are looking to go forced-induction, you can keep the stock (matched) setup and just force more air and fuel through the system at the same engine speeds. Remeber the crank and rods are self-limiting to around 500hp from the factory...

If you want to make the maximum power possible out of the original engine layout, then yes, an increased engine speed with forced-induction will get you there. It is also the fastest way to empty your wallet (and bank account!). Save money for the transmission and rear axle parts swaps to deal with the newly increased engine speeds.

More folks fall into the trap of building high-rpm powerband engines and bogging them down with the stock putt-putt tranny/rear end gearing. Please don't let that be you...

Brian

 

[stkjock]

Bsell - did you read the OP?


OP - when you say "redline" do you mean rev limiter? I run my stock block car to 6600-6800 at the track with out issue as of now.

also w/the TVS you may not need to spin it so high. how do you dyno charts look. if the car doesnt make power above x,xxx rpm, no need to run it up to that level or past it

 

[lito]

You dyno curves will tell you what to do, check your power/torque curve and knowing how much rpm you drop per shift look where it would leave you and decide with that data. I've seen people overspinning an engine so many times until you discuss the graphics with them.

 

[BSell]

Bsell - did you read the OP?


OP - when you say "redline" do you mean rev limiter? I run my stock block car to 6600-6800 at the track with out issue as of now.

also w/the TVS you may not need to spin it so high. how do you dyno charts look. if the car doesnt make power above x,xxx rpm, no need to run it up to that level or past it

Uh, yes I did...and answered his question in a more round about way than you attempted to.

To the OP, without knowing what parts you put in, nobody can give you a firm rev limit not to exceed. Of course, you can spin it till it blows, then tell everyone how fast not to go!

My original point was; buy into a system, i.e. I want 500 rwhp @ x,xxx rpms and buy accordingly. It seems folks around here have some 'favorite' shops that get them where they want to go. I am not a fan of 'sampling' from all over the place and then wondering what you have...

So tell us what you bought for internals and I am sure somebody around here will tell you a safe rev limit for your crank and rods combo.

I stand by my assertion that higher revs are not always the answer...

Brian

 

[Chris06GT]

Higher revs aren't always good like Brian said....But, since you are running a forged bottom-end, and normally 9 out of 10 times on a Mod motor, it is balanced and put together by a well known shop....So, therefore like the other guys stated, it all reflects back to your dyno charts....

For example......

My dyno sheet shows that my car starts falling off at 5k.....Therefore there is really no need to turn it more than that or around 5.5k....I power shift the car without letting off the gas, and it only drops a couple hundred rpm's....that way I stay in the peak hp range....But, most of the time I shift right at 5k because my peak torque is around 4300....Just refer to your dyno sheets once it is all tuned and set....

Chris

 

[stkjock]

Uh, yes I did...and answered his question in a more round about way than you attempted to.
Brian

didnt seem to as you talk about going FI and he stated he has a blower and a stroker from Livernois

I stand by my assertion that higher revs are not always the answer...

Brian

agreed

 

[DirtyDogOfTheDesert]

Cam selection and valvetrain are also very very important to consider. If your valvetrain is not up to the task of say 6500rpm, not point having a bottom end capable of 8000rpm.
When you stress the top end to the point of valve float, it dramatically weakens the springs, which can lead to valve float occuring at lower and lower rpm's the more often you push it to that point. For example, you might push your stock valvetrain to 6800 rpm with no problems, push it to 6900 rpm the next time, and float valves. Now the next time you hit 6800rpm valves float again, then may at 6700rpm the time after that.

My suggestion is, take small steps and figure out what works, especially until you upgrade your top end. I wouldn't go spinning it 7000+ because someone on the internet said it was okay to.

 

[Kraftsman]

You dyno curves will tell you what to do, check your power/torque curve and knowing how much rpm you drop per shift look where it would leave you and decide with that data. I've seen people overspinning an engine so many times until you discuss the graphics with them.

I havent taken the time to dyno the car yet. Its on my to do list, but I would rather take it to someone who is well known for tuning s197's. Everyone around here will run it just to see what hp it makes. If I dyno it I want it tuned as well. Agreed though, I should have thought about that before opening my mouth.

I wouldn't go spinning it 7000+ because someone on the internet said it was okay to.

Trust me, everthing is taken with a grain of salt. But all I'm asking for is opinions, everything will be discussed with a tuner before anything is changed.

 

[DirtyDogOfTheDesert]

You're in Michigan, make the road trip to Livernois.

 

[lito]

I havent taken the time to dyno the car yet. Its on my to do list, but I would rather take it to someone who is well known for tuning s197's. Everyone around here will run it just to see what hp it makes. If I dyno it I want it tuned as well. Agreed though, I should have thought about that before opening my mouth.

No you should still open your mouth and ask, if someone gets pissed is their problem, that is what these forums are for, I've learn a lot and still learn more everyday, search button is your friend but this wasn't the case. Keep asking, keep learning and when you've learn a lot (by reading and specially BY TESTING) then share to others, that is what I try to do.

Happy modding.

 

[limelight]

Dirty Dog of the Desert is correct.The stock valve springs are your RPM limiter now.They would need to be changed if you want to turn more than about 6800 RPM reliably.