ECM Friendly Camshaft for Turbo 3.1?

[dbtk2]

I have to tear the heads off of the engine, so I figure while I'm at it, why not just put a cam in the car. The problem I have is I want to find a cam thats gonna give me a decent power gain, but not piss off the computer really bad. The car already idles at about 950rpm +/- 100rpm at idle, so the computer shouldn't have a problem there (the car has a chip which raised the idle). I just don't want it to not know what to do about fuel and all that. I found the cam I would use if it was an N/A engine, which is the Comp Cams 260H (i think thats what its called). The problem is that its a turbo engine, and I don't know how well that would work. It should work better than the stock cam because it does have significantly more exhaust lift and duration but I'm not really sure. And basically I'm just looking for a gain over stock, whether it be 5 or 50hp, a gain is a gain.

If anyone has any ideas of a computer friendly camshaft that would work well in a turbo engine, thats what i'm looking for. If you don't think the cam I am looking at would work very well let me know.

Also, what should I do for lifters, pushrods, and valvesprings? I plan on spinning the engine to about 6200 on shifts with a limiter at about 6600, so I want the valvetrain to hold up.

I'm open for all suggestions. I wanna get this figured out soon, because I want to be able to buy the parts and tear this thing apart sometime in the next 2-3 weeks.

Thanks,

Shawn

[geoffinbc]

NO DO NOT use a Comp H260 cam for a turbo application, TOO MUCH overlap. Find a cam made for a turbo app. Small amounts over overlap are more desirable. A turbo cam will usually have a little shorter duration and a wider lobe seperation. Most turbo cams will actuall not be very wild and will not disturb your computer.

[dbtk2]

Any ideas on a cam that would work nicely for my setup?

Shawn

[geoffinbc]

Go look at the usual vendors. Comp, Crane, Lunati and Edelbrock. Find some, post the specs and we will help decide.

I dont wana do any shopping. You do that part, We will help you say yes or no.

[RacerX11]

The 260 cam is not really that wild of a cam, so it could work on a turbo engine. The Crane 2020 and 2030 are a little hotter than stock (more lift), but have tighter lobe seperation angles (104 and 109 degrees), which means more overlap than the stocker. The 260 has a 112degree LSA, which isn't bad for a turbo engine.

Check out these threads on the w-body board for some discussions on the topic:

http://www.w-body.com/forum/viewtopic.php?t=12424&highlight=cam

http://www.w-body.com/forum/viewtopic.php?t=7553&highlight=cam

http://www.w-body.com/forum/viewtopic.php?t=856

http://www.w-body.com/forum/viewtopic.php?t=936

http://www.w-body.com/forum/viewtopic.php?t=17726

You can also try searching on the TGP Forums http://www.netavalanche.com/tgp/index.php

There are a couple people who have tried the GM Performance Parts cam (re-badged Crane H260) with good results, although tuning seems to be required.

I just noticed you post over on the w-body forum, so you may have already done this search

Marty

[geoffinbc]

Meh. You can get KILLER turbo performance with the right cam. The proper cam will help build cylinder pressure while under boost and also let the exhaust gasses out at the right time in order to help with driving the turbo.

You can run almost any cam on a turbo car. But to really make the turbo shine and the boost do the work it is made to do you really want to be shopping for a turbo cam.

If you cannot decide call COMP they have great tech advice. If it were me I would not settle for an off the shelf cam made for a N/A engine

[Invasion1]

im using the GMPP version of the H260 from Crane

in my 3.1 turbo.............but some on W-body are suggesting that it will cause computer problems.........

i used that same cam on a 1992 3.1 and it worked Awesome!!!!!!!!!!!

so im still undecided......its a pain to have to change if it doesn't work out......

so i would like to be sure but this is uncharted waters

Dave

[dbtk2]

I was looking over some old notes that I took on the different cams available and found one that I had missed that looks very promising, but nobody knows if it works without chip work. It is the Crane H260 that has been mentioned here already, and for a turbo cam it isn't bad, but I don't know if it would work well with the ECM. It looks like what I'm looking for to me, it is setup to be a good turbo cam, but it doesn't have huge amounts of lift or duration, so it SHOULD keep the computer happy.

These are the specs for that cam off the top of my head, so a few may be a little off:

LSA: 112 degrees
Intake Lift: .427
Intake Duration: 204 degrees @ .050
Exhaust Lift: .454
Exhaust Duration: 216 degrees @ .050

Can't remember any other specs. I have the cam card on my other computer somewhere, just not in front of me so I don't remember. But anyways, it looks pretty good to me.

If nobody knows, I think I will just buy it and try it out. I know someone that is very good at chip tuning (has done the computer in my dads 12.2 second GTP a few times) for all different types of engines, so I can talk to him if the ECM doesn't take to the cam very well...it would just be nice to not have to do that.

Shawn

[geoffinbc]

before you get carried away I suggest you call Comp cams. A few guy over at S-series were looking for turbo and nitrous cams and got excellent help from Comp. I also believe it is a free call.

[dbtk2]

before you get carried away I suggest you call Comp cams. A few guy over at S-series were looking for turbo and nitrous cams and got excellent help from Comp. I also believe it is a free call.

I would give them a call if this wasn't such a time limited project. I hope to have the engine back together sometime in or before the first week in August. That gives me three weeks to order all the parts, recieve them, then tear the engine apart and put it back together, and I don't really want to be rushed on the project once i start it. I am thinking it will take them more than like 1-2 weeks to come up with a cam profile and make the cam and send it to me. If I had more time thats what I would do. However, this looks like a pretty good turbo cam, and it is about the same size cam I'm looking for (not looking for anything wild, just a mild turbo cam that will give the car a little more power), I just don't know if it will work with the ECM or not. I will be ordering it in the beginning of next week (get paid on Monday) and I guess I will be the first to try it out on the Turbo cars to see if it works ok.

I appreciate the help, and unless someone can find another mild turbo cam before like Monday, this is gonna be what I'm going with. If you look up the specs for the cam, it really is not a bad turbo cam, it actually says in one of the descriptions that i read that it was good for mild turbocharged applications, so it should be pretty good. It is obvious that they focused on the exhaust side when they made it, giving it more lift and duration with the intake, and not a lot of overlap (stock LSA is 109 and its 112 on this cam), so it shouldn't make a bad turbo cam. It is also supposed to idle pretty smooth. The powerband for it is exactly where I want my powerband to be, and it says that it is capable of spinning 6500rpm which is right where I want that to be. Its designed for the same compression ratio I have (its for 8.0 to 9.5:1 compression, I have 8.8:1). So the more I look at it, the better it actually looks. So, like I said, I guess we'll just see how well it works. I definately can't see it being WORSE than the stock cam, and don't really see how it couldn't be better than it.

Shawn

[donk_316]

hmm well my H272 has -2 degrees overlap and a h260 is just a smaller version so i doubt it has "waaaay to much overlap"

Hell my STOCK 85 ECM runs a H272 and #17 injectors.

[geoffinbc]

A 272 only has 2* overlap??

Anyway if it is indeed a turbo cam the go with it. A 112 lobe seperation will give you a nice small overlap with a good broad torque range

[dbtk2]

Not only does this cam look like the one I want, but I found out after investigating a little that I can have it and the lifters shipped to my door for $150.67 if I go through GMpartsdirect. So it actually is a cheap cam.

I guess I'll see how it works...I'm ordering it Monday.

Shawn