I want to know how high I will be able to rev my engine. The cam specs are 214/224 .442/.465, 2000-4500 powerband. But I am using 1.6 roller tip rockers, so it will be more like 216/226 .471/.496. Other cams with specs around there have a powerband up to 6200rpm. My springs are good to .500 lift, and its a stock bottom end, if that matters. I'd like to be able to rev pretty high because of my gearing.

 

wh would you want to rev it really high. your power prolly stops at like 5000rpms or maybe 5500rpms so thats all i would go. i dont know anything about cams or w/e your talking about but those rpms aound good to me. maybe you could get 6000rpms.
just take it for a drive and see what rpms your car quits pulling at.

 

"Powerband" could be what other brands call "Cruise RPM". 4,500 RPM isn't were that cam loses power. It's more like 5,500-5,700 RPM.

In both DD2000 and EA 3.0 that cam makes peak HP at 5,500 RPM.

 

This engine aint in the car yet. The old engine I had in it had a powerband of idle-3000rpm. All torque, had absolutely no power above 5K, but the engine would rev past 6000. So it had the potential to rev past 6000, but no power past 5000.

I can ask my question differently: My cam has a max rpm of 5500, but will 1.6 rockers and good springs raise its max rpm?

 

You're still being very vague. What do you mean by "max RPM"?

Why? Why do you want to rev your engine beyond 5,000 RPM if it doesn't make power there? No compute.

What is your goal? Just to sit at a stop light and rev your engine 'til the cows come home? I don't get it?

 

Not by much I would think. My cam is advertised to make power from 2500 - 6500 but starts tapering off at around 6800 rpm. I'm running 1.52 ratio rockers which make it .531 lift instead of .525.

 

my 305 revs to 5500 at a stop light when there is a import with a fart cannon next to me. hahahahhaha. nice when all i have a open y pipe,hahahahha. thing gets loud i cant wait til my headers are on.

 

My gearing is 4.03, 2.37, 1.49, 1.00, .76, plus a 3.42 rear end. In first gear I hit 27mph@5500rpm. So if i can rev it higher, I can get a couple more mph, and not be shifting into 3rd@45mph

 

what were trying to tell you here. is ... no power band no go. your block without an extrem amount of money into it will not be able to go above 6500 rpm and when it does your stock bottom end will look like it went to hell and back. so staying around a 6k rpm setting is good. very good.. i'm setting my motor up to have my power band peak at 6200. i'm gonna shift at 6k though cause it'll pull just as well though the next gear. i don't think your gears change when you go faster. lol maybe when you shift. but it will eb fine with what you have. ok get it. no past 6k it's that simple. and 5k is a weak rpm comom.....

 

Just out of curiousity, how do you have a 4.03 1st gear? You obviously have a 5 speed and I have never seen a 4.03 ratio available for any 5 speed trans that came in an F body.

 

damn you got a manual trans i was gonna day 3rd at 45 mph but still thats slow for 3rd you should be in second still til like 50mph if its a auto and manual prolly like 2nd 60mph my friends 03 mach 1 hes in second til like 60mph. when i race i stay in my auto in 2nd til like 50mph.

 

Its the T5 tranny originaly for the V6 engine. Thats why first gear is so low. It really gets the car moving as long as I have traction. Because of all that gearing, 1st gear gets used up very quick, so does second. Im gonna have the car dynoed to see where its max power is, but I just wanted to know just how high I can safely push it to. I'd be happy with 6000. Never planned on going past 6500.

 

ok good 6k is a great number. just don't be hittin it all the time. i am also using a v6 t-5 my first gear is gone liek the secnon i get on it 2nd is about the same way but when i hit 3rd it just coooks... 5spds are fun...

 

Id only be reving it to 6000 in 1st gear when racing. Or when I drop into second on the street. When I get it dyno'd I'll know where my peak power is and not go past that rpm when racing.

 

Why not just change your trans?

 

The max RPM to which your short block can survive, and the max RPM at which the induction system allows meaningful power production, are 2 different things.

With the cam you have, the car will go the fastest if you shift it at an RPM such that it's at around 4000-4200 when it hits the new gear. Winding it out farther than that will simply slow the car down. And that RPM is assuming an otherwise well-optimized induction system; no 882 heads with a Super Vic intake and stock exhaust manifolds, and stuff like that.

It is the sign of an inexperienced racer, that one wishes to simply run the motor to a higher RPM, without understanding that the car will go the fastest, regardless of the gearing, when the motor is kept always within the RPM range between max torque at the bottom, and max HP at the top.

Your dilemma is exactly the thing that makes those grocery-cart transmissions unsuitable for a performance application. Because of the poor ratio of time the car spends in gear and within in the engine's power band as described above compared to the time it spends with the clutch disengaged, it makes a car slow in the Ľ. That's why closer-ratio transmissions are sought after for performance applications, and ones geared to help compensate for under-powered motors, go into the garbage. About all you can do, is if the car runs up through the gears quick, learn to shift quick.

Screw 6000 RPM. Go get the car dyno'ed, find out where it makes power, and run it there. If max HP occurs at 5000-5200 RPM like it does in about every other motor with that cam in it, then that's where you need to stop winding it out.

 

RB, did you not read that??

 

Yes.... and that is really the best way to go. I also read a whole bunch of stuff about "I want to rev it to 6000"; which is a mistake.

Don't try to find ways to force the dyno to validate the "6000 RPM" business; instead, adjust your expectations and your driving technique to be in accordance with what it says. Numbers don't lie.

I might also add, those wide-ratio transmissions make a car slower on the street, by creating a situation where at various speeds, there is no gear available that puts the motor within its optimum power range. I think, once you get the numbers, you'll see that your gearing issues are a serious limit to your car's performance. "Revving it to 6000" when the motor produces no power there, as it surely doesn't, is counter-productive; and if your gearing forces you into that, then it needs to be fixed.

 

I'm sure he read that, but you are simply not listening to what everyone is saying. Pulling the tach to 6000rpm in your case is COMPLETELY POINTLESS! I would shift at 5000 max no ifs ands or buts. Hell I don't shift at 6000 and I have alot more heads intake and cam than you. I'm not trying to be rude, really I am just trying to help you understand better.

 

Woops, RB beat me to the post I guess.

 

im with rb on this, i had a trans that had like a 3.76 first gear from a 4 banger.

i had trouble in slow traffic parkig lot manners sucked because in 1st gear i had to make all kinds of noise due unneeded rpm, but 2nd would lug the car. and when i went from auto to that trans,

my quarter mile slowed down. by about 4 tenths, now i have a trans from an 85 v8 car with the 2.95 1st and the .63 od . but have yet to get a time recorded

this one compliments my v8 and 3.73 gears far better, than the 4 banger trans which was originally paired with 3.73s but with a far less powerful motor

my sig is quite out of date

 

The trans is really your biggest problem.

 

Not sure Id be able to find another T5 with better gears that dosent need rebuilt. The good thing about mine is that it is in great shape, no need to rebuild it. And I do care more about dependability than performance. I dont wanna go investing another $3000 into this car when Im prolly gonna sell it next summer.

 

One of these things is not like the other.....

At some point you've gotta make up your mind what's more important. If you want dependability, the ONE SINGLE THING you most need to do, is to avoid high RPMs.

You'll improve both, by getting the right transmission.

There's T-5s for sale in the classifieds on this site all the time. People aren't looking for $3000 for them (although I'm sure they'd love to get that....). They seem to go for less than $300 alot of the time. And it doesn't cost $3000 to rebuild one; as long as you get one with all the gears still good, the rebuild kit is about $200.