higher ratio rocker arms in turbo application

[thebeewantsboost]

i've got a 2001 camaro with a stock motor. and a buick grand national turbo. .63 exhaust a/r and .60 compressor.

from what i read it sounds like turbo cams, hardly change the the intake duration but change the exhaust duration quite a bit. they also try to remove the overlap. but that doesn't really pertain.

i was looking at some rocker arms, the intake was 1.9 and the exhaust was either 1.7 or 1.8.
would it be beneficial to my setup to get those, but use the 1.9 on the exhaust and the 1.7(8) on the intake.?

[ssms5411]

Re: higher ratio rocker arms in turbo application

Since you have stock cam 1.9 rockers would help alot, I run 1.7 pro mags with my VS cam and they work very well.

[thebeewantsboost]

Re: higher ratio rocker arms in turbo application

my real question is should i install them "backwards" 1.9 intake and 1.7 exhaust because its a turbo application.

[jughead]

Re: higher ratio rocker arms in turbo application

No. you should look at prj performance or theres a australian company doing taller and wider covers.

[ssms5411]

Re: higher ratio rocker arms in turbo application

With stock cam I would run 1.9 all around.

[1998silverbird]

Re: higher ratio rocker arms in turbo application

Your trying to mimic a Turbo cam with the rockers on your stock cam? If so Good Idea but I am not sure if its been done. You can try it and let us know how it went!

My thought is if you want a turbo cam then get a turbo cam!

[thebeewantsboost]

Re: higher ratio rocker arms in turbo application

why would i need taller/wider valve covers?
i'm going to use them "backwards" because i already have the parts.
yeah basically just mimmicking the turbo cam minus the lsa change. i wasn't really looking for a cam. i just found a good deal on the rocker arms, springs etc. and wanted to run the non traditional install by you guys. it's going to be a little while. can't seem to make time for my poor car.

[1998silverbird]

Re: higher ratio rocker arms in turbo application

why would i need taller/wider valve covers?
i'm going to use them "backwards" because i already have the parts.
yeah basically just mimmicking the turbo cam minus the lsa change. i wasn't really looking for a cam. i just found a good deal on the rocker arms, springs etc. and wanted to run the non traditional install by you guys. it's going to be a little while. can't seem to make time for my poor car.

Like I said, good idea.

Only thing envolved with bigger rockers in a bigger lift I think. Dont think rockers effect the duration but I could be wrong. So you could mimic the lift of a turbo cam but might not be able to effect the duration.


I would do a search over on LS1tech and see if it has been done on LS1/LT1 motors.

[thebeewantsboost]

Re: higher ratio rocker arms in turbo application

man, there are some sick cars on that site. especially turbo setups. i didn't find anything that pertained to this topic but i did make a post.

[bigbrian442]

Re: higher ratio rocker arms in turbo application

Changing rocker ratio does change duration and lift both.

[flamingchicken]

Re: higher ratio rocker arms in turbo application

Changing rocker ratio does change duration and lift both.

Exactly, it multiplies the lift by the ratio number, and similarly effects the duration.

[1998silverbird]

Re: higher ratio rocker arms in turbo application

I think your thread on tech got deleted!

So could you use a bigger rocker to open up the exhaust longer and keep the intake stock size?

[flamingchicken]

Re: higher ratio rocker arms in turbo application

I think your thread on tech got deleted!

So could you use a bigger rocker to open up the exhaust longer and keep the intake stock size?

Yes, give me a bit and I will find where zzp?? did some testing on split rockers for our engines.

[flamingchicken]

Re: higher ratio rocker arms in turbo application

found it. https://www.easyperformance.com/supp...er-arm-testing


http://shop.zzperformance.com/store/...o-Rockers.aspx

The rockers are produced with different ratios.

[thebeewantsboost]

Re: higher ratio rocker arms in turbo application

the rocker arms i have are basically an older version of those...
i'm pretty sure it doesn't effect duration... well... it sort of does.... but not really.... the cam doesn't change. so the valve opens at the same time... however.... the vamp rate is much steeper and therefore quicker... so you do have more.. "useable" duration.