88 WS6 TransAm GTA

iTrader: (1)

Ok, I have to order the cam this week because I need to get this short block into the car. Cam math isnt my strong point, so some help here would be great!

The combo:
-355
-10.5:1-11:1 compression w/58cc aluminum L98 heads. Im matching the heads to the 1205 gasket, doing some bowl work, polishing the exh ports, nothing heavy. Having milled for flatness, 3 angle valve job with stock 1.95/1.5 valves, valve guides machined.
-Stealth Ram
-MAF 165, no Im not converting to 730 SD.
-Hooker Supercomp long tube headers.
-Converter will match cam reqs, so that comes later.

This is not a roller block, so hydraulic will have to do for now. Comp cams recommended the xe268h:
.477/.480
224/230 @ .050
114 lsa

But I want something better... I put these numbers into DD2003 just to get a round about guess-timate, and I didnt like what I saw. Im not doing all this only to find out that I should have used a better cam, so lets hear it! I was thinking something along the lines of the xe284h...

BuckeyeROC

IMHO, I'd get better heads, and a cam with about 230/230 duration and around .575" lift on a 112 LSA.

88 WS6 TransAm GTA

iTrader: (1)

Better heads arent an option right now. Besides, these heads are giving me the compression I want, with the pistons that were already in the short block I got. This is a budget buildup... got the short block for $400, heads for $250, Hookers for $50, and some other parts I already had. All the major things I really have to buy new at this point is the HSR, cam, and a torque converter.

mrr23

comp cams 12-564-4 230/244 @ .050 .487/.501 lsa113*or
comp cams 12-560-4 224/236 @ .050 .477/.490 lsa 113* add 1.6 rockers if you want something with a little less duration.

also click the green banner.

88 WS6 TransAm GTA

iTrader: (1)

WOW I really like those numbers! As a matter of fact, out of all the cams Ive tried, thats the best one so far!

DD2003 results:
413hp @ 5500
436tq @ 4500

These results are with the STOCK, unmodified L98 flow numbers as well. I know it can be off, but I think its a pretty good estimate. And about stealthram.com... I frequent there alot, some GREAT info!

Well, thank you! I believe Ill be ordering my cam tomorrow. What stall would you recommend for this?

BTW: Are those numbers in your sig with or without nitrous? Theyre pretty damn impressive!

88 WS6 TransAm GTA

iTrader: (1)

I looked into that cam more, and I see that its more of a nitrous cam... should I look towards something else or will this be ok NA? Im acually considering nitrous in the spring so maybe this would be a good choice. Im wondering though, why did I get better results with a nitrous cam that I could get with most NA cams?

John Millican

iTrader: (1)

We have lots of good engine mechanics here. Not all are cam experts though. I would never call myself a cam expert either although I know quite abit about cams.

I would ask the pros (cam manufactures) on what they recommend. There are many factors to consider. Here's Comp Cams recommendation form you can fill out and fax back. Trust me they will also do a follow up phone call to talk to you personally in case you have questions after you receive their report faxed back to you.

http://www.compcams.com/Technical/CamSelection/

They are good people and have been doing this a long time. I would trust what they say. My next cam would definatly be a custom grind from them.

TRAXION

You cannot pick a cam without stating what you want out of the car. Big difference when comparing an all out performance cam to a cam that has driveability for daily driving. Also a big difference when comparing to a cam that can pass emissions. Also a big difference when comparing a drag racing cam to a road racing cam. What it really comes down to is where you need to make the torque in your powerband and if the cam needs to offer driveability. 230+ cams in 350 motors will cause issues with the power brakes.

Example,
IMHO my car has plenty of driveability (230+ hydraulic roller). However, I run an electric vacuum pump for the power brakes, have a 3600 stall converter, and everytime anyone stands behind my car they cry (the exhaust stinks to all he11 - and no it is not a tuning issue, it's called overlap). Some people love the car. Some don't love it. It's a personal decision. I think that daily drivers should stick with ~224 duration max for a 350 ... however, this is with a hydraulic roller so I don't know what that equates to with regard to a standard hydraulic.

Tim

NastyL98_T/A

Traxion said it right. For a daily driven car, stick with around or below 224* duration. Much less hassle tuning wise and driveability. Plus you dont really need that much cam in an L98. You want the lower duration to compliment the torque provided my the LTR setup.

88 WS6 TransAm GTA

iTrader: (1)

Yeah, I guess I should have stated what I wanted out of the car. I was tired last night!

Well, the car is pretty much a strip car... wont be doing much daily driving, but will if I have/want to. Emissions wise, thats already out the door with the long tubes that are going on it, so no concern there. Again, Ill match the converter to what the cam likes, so that will come later.

The cam Im very interested in at this point is the xe284h
240/246 @.050
.507"/.510"
It seems to put the powerband just where I want it, just at 6000 peak hp, peak tq is around 4500. I have no need to spin the enigne any higher than 6000, and a 2800-3000 converter would be ideal for it so it seems.

Next step down would be the xe274h
230/236 @.050
.490"/.490"
Which isnt bad, and considering my heads dont flow that great, the difference seems to be not much.

Nasty, dont need to worry about the tq of the LTR... as Im using the Stealth Ram.

88 WS6 TransAm GTA

iTrader: (1)

Alright well Ive decided to go a little conservative and use the XE274 k kit. For $309.99 ya cant really beat the kit... has basically everything I need for the valve train.

mrr23

doesn't matter that they say for nitrous. all they did was add to the LSA for better cylinder filling and promote more top end. currently i have a YANK SS3300 converter. here is a dyno of just swapping from the corvette converter to it. http://www.fl-thirdgen.org/mrr23/ima...tercompare.jpg

and yes those numbers are with the 150 n2o and using siamesed SLP runners/Edelbrock base. the e.t. is with the HSR. never got a chance to dyno with the HSR and n2o.