[Sting Ya]

There was a post on here a couple of days ago with some G.M.parts numbers for performance cams for a 2.4 engine for the life of me I can't find the post."What a drag it is getting old"Ill be doing my turbo upgrade in the next few weeks and as long as I have the car down I was thinking about some performance cams. I found one outfit JBP Performance that does a regrind on stock cams but they have no specs so I'm leary .Was I dreaming ?

 

[jeff465]

I remember the thread, but I can't find it either. I remember looking at 2 different GM website with different cam specs for the same pn#. With a turbo, you need a wider lobe separation angle to lower the valve overlap. Jim Dove at Dove manufacturing on 82 in Columbia Station knows a good cam grinder. I used to work there.

 

[Sting Ya]

Thanks Jeff ! Just down the street from me .If I remember right the post said that the cams could be used with a turbo that's why I was interested

 

[wspohn]

Far too many builders just use a profile for a normally aspirated engine on their turbo builds, which is not what you want. You want reduced overlap (some turbo cams can show zero OL at .050") so it isn't all going out the flue.

I had Comp Cams do a custom set up when I turboed a GM V6 for my Fiero. If you ask them they can advise you - I believe they do a cam or two for the LE5.

Just be aware that you will give up bottom end for top end power as usual with more duration but that isn't as much of an issue with turbo as they tend to have excellent bottom end performance anyway, unless you use a large turbo intended for all out top end power.

With the compression of the LE5 you are limited on boost anyway. Anyone bothered fitting special low compression pistons to allow higher boost?

 

[DaveOC]

Google search is your friend:

http://www.solsticeforum.com/forum/f64/interesting-75488/

a very recent post regarding performance Ecotec camshafts.

 

[jeff465]

I had Comp cams do a couple of various cams on my ZL1, ask for Chris if you decide on that route. The 2.4 has a big arm for a 4 banger (3.85" stroke) which will help the torque numbers. The lift on those GM perf. cams was around .500 and at 247 deg. duration that duration is pretty close to what you want with a turbo.

 

[wspohn]

Comp does a lot of custom stuff and the guys there really know their business.

I get very skeptical when anyone, including GM advertises any cam as being dual purpose NA or turbo.

Suggest looking at this interesting article in Hot Rod that talks about the camshaft design differences needed for different induction methods.

Cams for Turbocharged Engines - Hot Rod Magazine