I want to install the XR276HR in the LB9 in my 92 GTA. I know it is a little much but I plan on completely re-working the heads anyway so that is not an issue and I plan on some other engine mods and eventually rebuilding my motor with top notch internals and going with 10:1 compression while still using that cam.

My goal is 325HP and it's a street car. I'm going to have my tranny professionally built with a 2500RPM stall converter and I'm installing 3.42 gears. I really like the results that the XR276HR will give me, more so than any other cam that I've looked at.

My question is, I do not want to have to make a custom chip, I want to stick with my SLP chip. Can I get away with that? Are there any other problems that I've missed? If I cannot use my SLP chip, what would be the most radical cam specs that I can go with and still use the SLP chip?

Thanks!

Here is a link to CompCams site so you can see the specs on the XR276HR:

http://www.compcams.com/information/...6HR-10_001.asp

And here is a link to my engine Dyno2000 file with that cam so you can see the results:

http://www.TransAmGTA.com/Temp/SLP92GTA_XR276HR.dyn

281HP@5000RPM / 330FT/LB@4000RPM

 

While I'm at it I've also decided to go with a set of ported L98 aluminum heads with bigger valves too.

Bascially all I want to know is if I will need a custom chip or if I can get by with my SLP chip?

 

I'm no expert, but basically you can run anything, your results will be questionable. At the worst you'll go into limp home mode. With the money your spending on cam and head porting, its silly because you wont get the performence your paying for. At least get someone to do a burn for you.

 

Well if I have too I'll get into burning myself. I guess I'll have to

 

YES, you will need a custom PROM tuned for that cam. Trust me, I have it my 355.

You need at least 350 cubes to utilize this cam well. You will also need at least 10:1 compression, bigger injectors, high flow runners, headers, bare min. 2,400 stall, and 3:42 gears. This is what Comp told me when I bought mine.

This cam is overkill for a 305 and there is no telling what perameters have been changed in the SLP PROM, but I can gaurentee you that it's probably not even close! I'm on chip revision number 7 (DIY - PROM) and I still have a long way to go. Ed Wright didn't even get it close, yes, I first bought a fastchip from Ed Wright and (the car was running WAY to rich with it). So, be prepared to start learning as I am about tuning your own PROM's (it's worth it!!)

I can say this though, that cam idles surprisingly ok and it sounds MEAN as hell!

Just my $.02

Mike (1bad91Z)

 

Well I plan to eventually rebuild my engine for 10.1 compression and I already have everything else you mentioned except for the bigger injectors.

I think with all my mods it will do quite nicely in my 305 once I can burn a chip that will work well.