Luke Skyjacker

iTrader: (1)

Got my LQ4 in my RX7 and as it sits it is bone stock (even the pan!) besides an eddy intake & blowthru carb. My question is this:
if I shift @ 6000rpms will changing the cam really help?

I don't see the need to turn the motor super hard (7000) if it's not really gonna make a bunch more power. I understand driveability will not be a factor as both are stock cams. I already have the LS6 cam and springs. The rx7 is very light (back-half car) @ around 2300 #s. Car will be driven regularly on the street at around 14#s boost. So would I see tangible gains from the cam swap? Right now seems like alot of trouble for minimal results. Convince me why it's not

JAX04

iTrader: (17)

do you have pics of your setup?? would love too see

I would change the cam, Why do i feel like i saw a dyno graph of the stock cam falling hard off after 5500rpm. I wont swear to this, but i think i remember. And if youve got it, use it

Luke Skyjacker

iTrader: (1)

I need to get some updated pics since I've gotten the turbo mounted. Will try tonight.

gnx7

iTrader: (28)

The stock cam supposedly falls on its face around 4500rpm.

BAD-LSX-7

iTrader: (10)

yes a aftermarket cam is ideal

JAX04

iTrader: (17)

https://ls1tech.com/forums/forced-in...ance-data.html

Check this thread out

XtremeDime

iTrader: (16)

I remember when I asked this last year, people were saying they were picking up almost 40whp with just an ls6 cam over a stock ls1 cam. I would expect similar results with an lq.

Luke Skyjacker

iTrader: (1)

I'm gonna get some real results against stock, LS6 and a lingenfelter -3.

Any negative feedback n the yellow ls6 springs? They look pretty weak, I understand they work great for stock apps but repeat high rpm pulls against boost? I've typically used slghtly overkill valvesprings on my SBC.

robbyredneck

iTrader: (1)

i can tell you now by 5000 and 9psi the party is over. keep up on this thread i want to know if its worth pulling the cover

Blown06

iTrader: (32)

Parish did this comparo on a stock 5.3. Search his threads. It was in the fairmont.

pwrtrip75

iTrader: (8)

I find it hard to believe a cam would make it just all of a sudden break up and drop power rapidly once it hit 5000rpms. That has nothing to do with the cam....valve springs maybe. That dyno graph with it breaking up has got to be something else.

My friends BMW with a 5.3 in it has the stock cam, stock ls1 intake, we put better springs in though... it pulls and pulls up to 6500 and wants to keep going on 15psi.
The factory's advertised RPM band for that cam should increase with boost I would think.
Seems to work just fine.

Luke Skyjacker

iTrader: (1)

Found the thread: https://ls1tech.com/forums/forced-in...o-numbers.html

I really want to agree with the valve float theory. The results are hard to dismiss though. Even if you just compare the numbers before the 5000 "peak" the z06 cam seems to be surperior enough to warrant a change considering cost & effort.

Hank Peabody

iTrader: (2)

My LQ4 with stock cam and stock springs peaked at 520whp right at 5500rpm, pulled fine to 6000rpm at the strip, never had any breaking up.

slow67

iTrader: (2)

Guys, the LQ4 cam isn't the same as the 5.3 cam.

Luke Skyjacker

iTrader: (1)

Hank - How much boost was the 520hp on?

Hank Peabody

iTrader: (2)

The original poster is asking about the LQ4 cam and the 5.3 is actually smaller, so it should have less valve spring issue than even the LQ4 cam. Both tiny cams though.

13psi on the dyno, would creep to around 15psi at the track

pwrtrip75

iTrader: (8)

I think the cam thats in the 5.3 is actually a 99 LS1 cam. But regardless.... that dyno graph of it breaking up and getting all choppy at 5000rpms has nothing to do with the cam.