LS4 Performance - Rocker Arms for LS4

Hello. I have seen on www.drivewire.com a set of crane rocker arms advertised to fit the 2005 Grand Prix GXP. It is at this address http://performance.drivewire.com/getparts/index.aspx?pdef=Rocker%20Arms|Pontiac|GRAND%20PRIX |2005|GXP|||||Engine%20Components. I checked Crane's website and this part number is showing that it is for the 1997-2004, LS1, 5.7L and Vortec 4800, 5300, 6000 engines. Would these rockers fit the LS4? Could anyone shed some light on this? Thanks.

Yes they fit, what size are 1.7's, 1.8's or 1.85 (This will give you more lift and is a good time to change the springs, ls6 springs worked well for me. I had the kit here at the shop for a LS1 1.80 rr, pushrods, studs, g plates) I do not have any DOD problems. I also did not fell any more HP for this mod I will be going to the dyno soon.. My kit was the $700

Yes they fit, what size are 1.7's, 1.8's or 1.85 (This will give you more lift and is a good time to change the springs, ls6 springs worked well for me. I had the kit here at the shop for a LS1 1.80 rr, pushrods, studs, g plates) I do not have any DOD problems. I also did not fell any more HP for this mod I will be going to the dyno soon.. My kit was the $700
I'm sorry Dales- does this mean you actually made the swap on a DOD? Was it a truck or the W-body??? You said you had not felt any additional HP, did you feel a loss? There was speculation that that the higher rate springs may play havoc with the lifters, as in the lifters wouldn't be able to overcome the extra force of the springs.

Very interested in what's happening. When are you going to the dyno??

Yes it is my 06 Impala SS, I made a cold air kit for it and a 75 shot of NOS (Dry) I had the RR kit and said what the hell as for the power 10 to 15 is hard to feel.. TQ steer is so bad I have to drive like i am 80yrs old.. So far so good... PS the pushrods 7.385.. I just wont to get it tuned SO BAD..

Compared to my turbo mazda, and other FWD cars, the torque steer on the impala is non-existant. So for you to have such problems, there must be substantially more power added than 10-15......

vinci is in the middle of installing the 1.8 accelerated lift rockers with the dual springs as i type. it's on a 2006 impala SS. they have already baseline dyno'ed the car as well. once they are done, i'll see if i can prod them into getting the info up on their website.

vinci is in the middle of installing the 1.8 accelerated lift rockers with the dual springs as i type. it's on a 2006 impala SS. they have already baseline dyno'ed the car as well. once they are done, i'll see if i can prod them into getting the info up on their website.

Very interesting. Please let us know as soon as you know more info. Thanks.

vinci is in the middle of installing the 1.8 accelerated lift rockers with the dual springs as i type. it's on a 2006 impala SS. they have already baseline dyno'ed the car as well. once they are done, i'll see if i can prod them into getting the info up on their website.
We appreciate that!!! Many have been waiting a mighty long time for that to be done... :hail:

you guys need to get a PCM that is tuned if you want to feel anymore power.......the torque mgmt is shutting down any gains from the mods you installed

and another thing is that Crane Kit sucks.......... 700 bucks for what those shitty ass rockers?

That kit is not LS4 specific it is the same kit for all the LSx's

you guys need to get a PCM that is tuned if you want to feel anymore power.......the torque mgmt is shutting down any gains from the mods you installed


I would assume the LS4 is similar to the LS2, in that any gains the computer senses (air/Fuel out of the "normal" range) the engine's timing is polled, and in the end it's as slow or slower than stock.. need a tune on these things, same with less backpressure I hear as well.

and another thing is that Crane Kit sucks.......... 700 bucks for what those shitty ass rockers?

That kit is not LS4 specific it is the same kit for all the LSx's

wow, you have a bad experience with them? or just basing that statement on what you've read and heard? do you know what comes with the $669.00 price tag? other than crane's name engraved on them. :P

and who said they were LS4 specific?

finally got around to putting the results up on the web

http://www.vincihighperformance.com/IMPALASSPARENT.HTML

VHP 1.8 ROCKER & SPRING INSTALL
GAINS OF 18.1 rwhp & 16ft lbs tq

Are Those Results With Or With Out A Computer Tune? Was The Car Tuned To Begin With?

only thing done was rockers ans springs. stock tune before and after.

why dyno in 2nd?

CAR RUN IN 2ND GEAR TO PRESENT LONGER GRAPH TIME.
look at the graph. it starts at 2500 rpms. most cars run in 3rd gear won't let you start that low without downshifting.

hmmm. i guess im used to my tap shift where i can lock it in third gear, but it still won't let it go wot under 2700 no matter what gear im in on the dyno.

all my charts are from 3k-5800 in third

dunno

that might explain the higher numbers then normal for stock

Does anybody know if the stock springs will work with the 1.8 rocker arms? I know aftermarket springs are usually better than stockers for controlling valve float, etc. but I wondered if the stock springs will bind with the added lift.

stock springs are good for that, stock

adding lift will cause coil bind in higher rpms.

pretty simple really, if you have gone that far, might as well do the springs

I was wondering if your dry 75 shot of nos is before or after the mass air flow sensor. I have been hearing of the poss of a dry shots before the maf sensor. I have an 06 Imp SS and want to install a small shot of nos. Any info on an install would be greatly appreciated.

a dry shot before the mas works fine

been there done that
now am runnin a wet kit

just besure to use a wideband to adjust the nozzle so it doesn't freeze the mas air.
move the nozzle around so the a/f stays consistant all the way up through the rpms. if you freeze the mas air. it will start to go up in the a/f range
from 11.3 and start climbing to 13.0-13.6

it's all in how you aim that little sucker

What nos brand did you use if you don't mind me asking.

N.O.S. is what im using. just a simple kit i converted from a dry kit to a wet kit