I has seen camshafts that are made just for computer controlled cars. Is there really a differance, what cam do you guys recoment for a 89 L98 with Flowmaster Cat-back, hooker headers, and ported plentum, and other little mods.

 

Yes their really is a difference, yes you need to get a cam made for a computer controlled car.

Cams are like beer, all of them are good in someones opinion, but what I think is good you think is bad. You just have to figure out what you want and then get the right one. Base your decision on your final engine combo. Don't put one in now when you plan on making a head change in six months and then change cams again. Personally I'd get Desktop DYNO and try some out if you want to get serious about it.

 

That is another thing, where can i get Desktop Dyno? I have been wanting it so i can learn what different changes do.

 

In terms of cams for your motor there are three things to keep in mind:

1. You will need to get a roller camshaft(all production SBC after 1987 use roller cams). This means the $99 "Summit Special" won't work for you unless you convert the rest of the valvetrain for flat-tappets.
2. The computer likes to see a healthy amount of vacuum. "computer-compatible" cams have limited amounts of valve overlap to promote vacuum. This limits how big you can go without majoring reprogramming of the PROM.
3. Because of the relatively poor exhaust ports on stock heads, the factory cams are biased towards the exhaust lobes(increased lift and duration over the intake lobes).

Desktop Dyno is a good program for seeing how different changes affect output, but in my experience it does very poorly at modelling TPI engines. You can purchase it and most performance outlets(Summit, Jegs, etc.,...). Just don't put too much stock in the numbers it predicts for a TPI setup.

For your current setup, a good cam choice would be the CompCams XR258HR-10(SLP sells an identical cam for $100 more). This cam should boost your output by 15 - 20 hp, without sacrificing any drivability or reliability.

 

my opinion of desktop dyno is that it's worthless except for playing around on the computer when you're bored. It doesn't work for all cars & combinations. It was way off on my combination. Simulations are no substitute for actual testing and tuning.
I would recommend the camshaft that I run (in signature).
IMO

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*I do custom performance mods on Edlebrock Performer carburetors (dualplane intake mods in the works),
White 1986 Irocz, 305 with iron #416 heads,
383 with aluminum TFS heads,
Edlebrock Performer-RPM intake and Performer #1407 carburetor, +110hp shot of crack, 700R-4 tranny, Vigilante 2400 lockup converter, 3.25:1 Ford 9" rear, Mcreary Road-Stars, SLP-stainless 1.75" shortie headers & Y-pipe, single 3" Borla exhaust, Linginfelter-TPI camshaft part number 74216 pulls 17" vacuum solid. Cam specs 213/219 @.050 114-LSA, sometimes advertised at 216/219 @.050 112-LSA .462/.470 lift @1.5:1 ratio. Using Harland Sharp 1.65:1 roller rockers. MSD-6AL, billet distributor, multi-retard, blaster-3 coil, and RPM switch. SouthSide machine subframe connectors, SSM lift-bars, Moroso 4" underdrive crank pulley.

N/A runs 10.9 @124,
Crack-runs 10.3 @135
haven't run at track since Oct-99

 

this is dedicated to all of you who put faith in computer simulations when designing your car & engine.