So Can I Rev Higher Now?

[04YELLOWGT]

Well the car was supposed to be done yesturday with my new short block and cams put in. But I didnt know I needed an 8 bolt flex plate so we are now waiting on it. I was wondering though, now that I have the cobra crank and forged internals can I rev the car past 6k now like the cobras can? I know I can continue to make power past six since the blower but I dont know it is safe to do so. If you guys could give me some info on this, that would be great since I have to wait another 2-3 days to get the part and another day to finish the car.

Thanks :SNSign:

 

[Redfire03GT]

There's a bit more to it than that. You would have to make sure that all the "moving parts" in you engine is capable of sustaining a higher rpm than 6k.

For instance, if I were to try and make a high revving 2v, I'd try to get a light weight rotating assembly, along with valve springs that can withstand prolonged high rpm usage without valve float. Beyond that, I'd try my best to make sure all it's supporting parts are also as efficient as possible. Like an aluminum flywheel, aluminum driveshaft, etc. Anything that can reduce the effort needed to even spin the motor, would be a plus.

But that's just the first step. You'd have to actually make power all the way up there for it to even be worth it.

 

[steveb24]

i thought that had something to do with it being a 4 valve.. thus allowing it to make power in that range. its useless if ur not making power up there.. but yeah im sure u can safely do it now.

 

[04YELLOWGT]

Well with my blower and cams I would imagine that I would be making power but I guess Im not sure.

 

[Redfire03GT]

Unfortunately, it's not as clear cut as that. You could have blower cams and a blower but stop making any real power at 6k. Your cams would have to have been ground to make power up in that rpm range, the blower, I'm sure will be fine. But then you'd also probably need a better flowing intake because once again, you'll be limited in power production.

 

[steveb24]

right.. The intake is what makes power.. aka airflow. Cams are only a part of the intake/ flow process.. while they can be designed to make a heck of a diff.. its still an unported 2v. (if i assume correctly)

 

[Tim2002GT]

If your running stock 2V heads, I would think they would be your bottleneck once you get up into the 6000+ rpm range.

 

[Dusstbuster]

High revs will also stress out the valvetrain. That is what will cause damage if revved too high. Things start slipping and you might get PTV contact and ruin your pretty new forged shortblock. Unless the valvetrain itself is set up for high revs, whether or not the engine makes power up there, I wouldn't rev it til the valvetrain can handle it.

 

[thomas91169]

your topend is your bottleneck for rev's. it cant flow up there and you can get into a situation where a valve may float and smack a piston and you now have lots of problems and at that rpm its catastrophic. get yourself a good head/cam/valvespring combo so you can make power that high and do it safely.

 

[tmoneyballin]

When was the last time you dyno'd your car? Logically, if you wanted to "know" you could just look and see at what rpm your car makes its peak horsepower. Get a tachometer that will read accurately with a shift light. If your car makes peak horsepower at 5,900 rpms then you would want to shift at 6k(reaction time) at the most - otherwise your are beating your car for no reason.

I have a cobra that is built and it LOVES to rev to 7,000+ rpms, but as the others stated it is designed and built to produce power beyond 3,300 rpms (when the other valves open) not a 2valve like your GT that can NOT rev that high. Sounds like you put a lot of money into your car - take care of it and don't rev it beyond where you make useful power.

I personally prefer a blown gt that will RUN, compared to a blown gt with a blown up motor that will NOT run...Just my .02