I recently emailed compcams for a recommendation for my daily driver L98 TPI. It has stock iron L98 heads that have been ported and "cleaned" up a bit. The intake plenum has also been hogged out, along with the TB. I have some SLP runners Im going to put on today too. I also have a TPIS afpr set at 52psi and a custom PROM. When I emailed them I told them all of the mods I have done to the car, including the Hooker LT's, Mufflex Ypipe and dynomax catback. Anyway, their recommendation was a TPI grind, .444lift Int/Exh, 212/218 duration@.050 and a 114 lobe sep angle, 110intake cntr line. Is that too little?? Are they just being conservative? I also noticed in the catalog that the cam is emissions legal, which doesnt mean much to me. I know the TPI doesnt like over .500 of lift stock......but I also read somewhere that the TPI likes high lift with short duration...to build up pressure quicker??? ANy thoughts on this? suggestions???? Im lost ......

 

They chose that cam for you because of your heads. The stock springs are (safely) only good upto .450 lift.

If you look in the catalog, the biggest TPI cam that they recommend is the cam I'm running. (CC XR276HR-12)

.503/.510
224/230 @ .050
112 LSA
108 ICA

I'll post the link to that cam in the catalog if you'd like.

 

Hey. I basically have the same set up as you but I'm running a Comp 08-302-8 cam. I nought this cam from a guy pretty cheap but it has worked out well. Above 3000 I can tell a big difference in power though it feels I've lost a slight bit of low end. It idles well and hasn't given me any problems. I'm still runing the stock prom which you aren't but never the less it works well. The cam is a Com 08-302-8.

210/220 @ .05
.48/.48 lift
108 CL
112 Lobe seperation.

Not trying to sell you on this cam or anything just let you know how it has worked out for me. I haven't been to the track since the install so I can't comment on any solid power increases. I fell that the car could handle a slightly bigger cam though.

David

 

That must be where I messed up...I forgot to mention to him about have the springs replaced when I had the head work done....The springs I have now are LT4 springs and retainers....good for about .550lift I think?? I know they are the ones that go with the Hot cam.....my buddy bought the cam kit and didnt need the springs....or retainers..so I got them cheap and figured while I had the heads off...Id have them machine them for the bigger springs.....Ill email him again and see if that would change anything...

 

Hey,

I have a similar set-up with the XE264HR I think the specs are:


.487 /.495
212/218
112 separation

Nice cam, mid range is very good, low end is near stock, top end is OK, car will rev much higher, but not much power over 5K, made for LTR. really is a good street cam. overall very enjoyable,


You do need valve guide clearance on stock heads to be safe, plus they recommend a 1.44 double spring because of the extreme grind lobes aggressive ramp rates. LT4 springs should be ok.

Also not selling this cam, recommended by comp also, just sharing my experience. Car is running basic ARAP bin right now. could use more tuning, probably more power hidden right now.

Good Luck

P.S.
I am running a pro built/ A.C.T. 2200 stall converter also

No times/ this is a daily driver/ **** embaraser

 

Hey Black91, nice car....looks identical to mine(with the paint on it anyway). The compcams advisor emailed me back and gave me a second opinion.....he recommended a custom grind....High lift, short duration. Specs will be .500lift int/exh, 200/203 dur@.050 and a 112lsa. The specs are damned near identical to the stock LS1 cam found in crate motors.......except this cam will fit.. Anyway, any suggestions on that? I think that will work just fine. I didnt want to get to crazy with the motor......I did that before, and it was a tempermental bitch on the street. thanks for all the help though....I will post new dyno numbers when/if I get the cam....

 

The factor that determines how well Comp's latest recommendation will work is your cylinder heads. Excellent flow and high velocity, like on LS1's, equal good cylinder filling. Stated another way, if you've got a great set of heads you don't have to hold the valve open as long as you need to with a mediocre set of heads to get equal cylinder filling. Since the L98 iron heads are pretty weak and don't respond to increased lift like aftermarket heads, bumping up the duration (within reason) is a good way to increase cylinder filling. So, if your iron heads flow well or if you're planning to put on better cylinder heads in the future that cam will be a good match for the street. If the heads are close to stock then more duration would be beneficial. BTW, you could probably have Comp grind that new cam on a 110 LSA to bump up the low end and mid range and still be completely computer friendly due to the relatively low overlap of a short duration cam.