Steve10

I will be doing the LT1 intake swap in a couple of weeks. To get the most out of it I'll need to rev much higher. Guys that are running this or miniram...where are you shifting? I think this motor and valve train should be okay. Should I start planning for a higher stall and gears, also? I'm currently running a 2500 and 3.27's. Frankly, I'm curious to see if a little loss in torque will let me launch harder. I'm losing too much either spinning or waiting to get in it, even with the Nitto's. My current G-tech mph is 109, so I should be close to 12's if I could hook up.

camaro6spd

Gm says 5800 is the max RPM...I guess that is for sustained time.

99Hawk120

The given spec is for the "Maximum Recommended" Engine RPM. I've asked several people and no one has been able to tell me if that's the "yellow" line or the "red" line. I've set my RPM limiter for 6000, figuring that's probably safe.

Steve10

My plan is to concentrate on getting my part throttle BLM numbers close, then go to the dyno. I'll take my burning eqip. with me and tune WOT. I guess I'll over rev it a little and see where the peak is.

11SEC91Z

iTrader: (4)

Hey steve10..I made a similar switch..Ididnt have a zz4..but u might as well say that what it was i had a 350 with a TPIS zz9 cam and corvette aluminum heads..Any ways boy what a change!Your car is gonna feel alot differnt.You lose low end but the car is actually faster.Iwent from 12.92 with slp runner and eldebrock base to 12.43..I did have more converter than you too..You might want to change to around 3000-3500..But anyways i went from shifting at 5400 to around 6200-6300 comfortably..Yeah big change..But its all gonna depend on your combo..some cars respond differnt..Anyways good luck

Steve10

11SEC91Z, what gear are you running? What was your mph before/after.

Thanks

11SEC91Z

iTrader: (4)

went from 104 to almost 110 with mini ram..and i have 3.73 gears in my car..but i run a 28"tall tire

TRAXION

I rev my STOCK Bottom ended L98 to 6500 every time that I am in the car. I know of several others that have done the same. If we can do it on an L98 bottom then you can do it on a ZZ4 bottom. My only concern would be the valvesprings that are on those heads. But, the bottom end should be able to handle it without a problem.

Tim

'87FAKE-IROC-Z

I run a stock rebuilt bottom end and a SR, but i spin to 6500 with no problems.
A Fluidamper helps keep it smooth, and my valvetrain can handle it.
If those vette/zz4 heads are stock, like said before, check the springs.
The ZZ4 bottom end is pretty stout. If me and Trax are OK, you sould be too. Just watch out for harmonics and valve float.

Steve10

The motor was ordered with the LT4 cam kit which includes 1.6RR, springs and retainers. I'm not for sure how much better these springs are than stock ZZ4. Anybody?

99Hawk120

I think the stock ZZ4 L98 heads have LT4 springs in them.

Trax, I figured the limit was the valvetrain, but thanks for confirming my suspicious. I suspect "as-is", though, that the motor is pretty much done power-wise at 6000 anyway. Some day I'll take it to a dyno and see.

Steve10

Just called Scoggin-Dickey and they are the same springs stock or in the kit. The guy I talked to said 6000 should be fine, but valve float would likely start much over that. Once I get the LT1 intake installed, I'm definately investing in the dyno trip to see where my peak is. It will make WOT prom burning much easier too with the wide band sensor.

GTA91

iTrader: (1)

So with ported IRON L98 heads and a LT1 intake, should I run the ZZ4 or LT4. Both are sitting here looking at me.

Free Bird

iTrader: (1)

Thats correct, they are LT4 springs.

Randy92Z

iTrader: (3)

Im running a stock bottom end L98 and Trick Flow 23* heads. The instructions for my TF 23* said with there valve springs max rpm is 6500. I usually spin it to 6500 when I shift, no problems thus far.

Mark_ZZ3

I know my ZZ3 cam and ZZ3 springs floated at 6300. I am not sure about the ZZ4 springs as GM changed them. Check which ones you have, check the spring pressures open and closed.

Then call a cam manufactuer and see what they recommend for the RPM you want.

MArk.