kill4thril

ok so i have been looking at a new cam for my car and i used comp cams cam quest and it recomended this cam http://www.summitracing.com/parts/CCA-08-423-8/ but it says its not computer compatible ? i am using a tbi set up with the ebl flash would i be abel to use this cam ?

dimented24x7

iTrader: (2)

Vacuum will be a major issue as it limits the fueling resolution at idle. For a speed density system, Id steer more towards cams with larger LSA's. That one will pull around 8-10 inHg at idle, which is kind of low. It can be done, but itll be a bit more aggrivation to get it running right.

Also, the cam needs to match the rest of the setup. If you have high flowing heads, then your most often better with a slightly smaller performance grind as it builds better cylinder pressure at low engine speeds. This is especially true with the XE rollers since they have a lot of lift under the curve. Dont get too hung up on running X degrees of duration. Telling us a little more about the engine will help in steering you towards a good cam selection.

kill4thril

The motor is a 355 with vortec heads with comp cam springs that give the heads a max lift of 550 it has and edelbrock performer intake flat top pistons and hooker shorty headers the tbi is from my old 305 but I have an afpr and injectors from a 350 I will be geting a new fuel pump too when I get a chance to drain the tank I also have the ebl flash to tune the car. But I'm looking to get good mid to top end power out of the motor thanks for the help

dimented24x7

iTrader: (2)

Your going to need a bigger TBI for sure if you want it to have good top end. At least one with 2" bores. Those are about the same flow-wise as a 650 CFM carb, which should meet your needs. The stock 1-11/16" or whatever it is TBI will strangle the engine where that cam makes its peak power. Also, if you have good flowing heads, you dont need as much cam. This is especially important with TBI as the injectors dont do well at high RPMs. The high firing rate essentially cuts into the total time available to deliver fuel. If you crank up the fuel pressure to get the fuel you need out top, then they have a hard time during idle. I ran into this with TBI myself. I could get the fuel out top, but then my PWs would drop into the microsecond range at idle.

I found out when I went from an isky mega hydrolic that was about the same as the XE268 flat tappet to an XE258 4x4 retro-roller. Lot smaller on paper, but it actually still gives almost the same performance as the big flat tappet with my trickflow 195's. For reference, my fastest 0-100 MPH time with the old cam was 11.8 secs while the new one was 12.4 secs. Essentially for a small loss in top end at 6k I gained great drivability and 2x better fuel economy. The bottom line is that you need to weigh everything involved. With modern heads, less cam is needed since they flow much better than what was around 20 or 30 years ago.

Just putting my finger in the wind, I would say a good choice would be the Comp Cams XFI 260 or 268. They have a bit less duration, but the wider LSA will help with the idle and low speed torque with only minimal losses out top compared to the other cam. Im guessing you wont go much past 5.5k RPM, so a larger grind isnt really needed. The XE276 roller, IMO, is too much cam for your application. Keep in mind that these rollers have very aggressive lobe profiles. Not like what youd have for a bracket racer, but they have a lot of lift "under the curve", as they say.