So, I blew my 178k mile cam only motor on a road track a few weeks ago and I'm in the process of rebuilding. I'm starting with a rebuilt LS6 block w/ GM rotating assembly king bearings, mahle rings, ARP bolts. I'll be running SLP lid, stock MAF, LS6 intake, pacesetter 1 3/4" LTs, ORY 3" magnaflow catback with a cutout in the I pipe. The old set up had Thunder Racing's TR224 cam 114 LSA and a 25% underdrive pulley as well. That setup was making 387hp/385tq at the wheels. Oh yea...4.10 gears.

Here's what I'm looking for, a heads/cam combo that will get me over 420rwhp/420rwtq with more power under the curve than I had with the TR224 and stock LS1 heads. I do not want to change any of the bolt ons if at all possible. Budget is definitely a factor.

My initial thoughts are PRC 5.3 stage 2.5 with a 228/232 59x/59x 112 +2 cam.

The goal being to be able to use midrange power (2500-4000rpm) for the corners and still have good peak numbers for the straights. I just don't want to have to carry high RPMs for the whole course.

Thoughts? Recommendations?

 

Personally I'd consider AFR castings due to lifetime warranty given the application

 

Whoa...wait...what? They have a lifetime warranty? How did I not know this?

Ok...so...assuming AFR 205s?

 

My old LS1 setup had a cam almost identical to one you're describing and with the PRC 5.3 heads and 4.10 gear the car had really good mid range power. With that said any good aftermarket casting that's designed for the LS1 will generally have better mid flow capability, but it obviously comes at a cost. So basically 420 shouldn't be problem with the 5.3 head setup you're talking about, but something like a good AFR or Trickflow head will do even better

 

Would I need to look at having the AFR's ported or as cast will get me what I'm looking for? 205s? 215s?

 

wow...I guess they aren't even making the 205s anymore...so 210s or 215s?

 

Nope a good as cast 205-215 aftermarket head will outshine the PRC 5.3. Peak flow may be close (just depends on the exact head) but low and mid flow won't

 

I'd go to the AFR 215 castings straight up. If you want every bit you can get out of them, call Tony Mamo for his 220's, which are worked over AFR 215's. You can get your power goals with a moderate cam with heads like that.

 

I thought all of AFR's heads were CNC'd ports and chambers....

 

In a perfect world in your shoes I would run the AFR 205cc heads. I'd mill them down to get compression in the 11:1+ range and run a 22x intake duration cam suited specifically for those heads. Some of the most impressive torque figures and low to mid-range figures I've seen on a stock bottom end N/A LS1 have been cars with those heads not to mention people seem to rave about the throttle response. Only downside is the cost and you mentioned budget being a factor. BTW, I found them on available online, don't think it's a sponsor so I won't post up the link.

I'm adding the Streetsweeper HT cam and .040 Cometic head gaskets to my bolt-on LS6 to primarily make it a more fun street car but I'm also secretly hoping it gives me a little more juice coming out of the turns in 3rd gear so I can totally see where you're coming from OP. If I had the money to burn I would of gotten the AFR 205s and a cam to match.

Edit: I am not familiar with the other AFR offerings so there may be a better choice from them available but I have been extremely impressed with what I've seen from the 205s.

 

Yes they are...i looked it up after my last post.

 

Thanks for the input... looks like I definitely need to go AFR, with the warranty and the low to mid flow numbers make it the best choice. I'm definitely interest in getting 10.5 to 11 :1 compression, so if have tho mill the AFRs regardless of which volumn I go with... Will that void the warranty?

 

If you have 93 octane I'd go to 11.5. 60cc should get you there. And no it won't void it

 

We do have 93, but I tend to move around so I do want to be able to run 91 if I have to.

 

I would look at the 224/228 114+2 with the AFR 205.

 

We should get on the phone for a bit....I can guide you in a more productive slightly different direction that will make more peak power and more peak torque.

Shoot me a PM with your contact info and I will try to reach out

Regards,
Tony

 

PM Sent!

 

If your planning on road racing with SCCA or similar, make sure you read the rule book on the class you intend to run in. A small change in displacement can net you > 400 lb weight penalty.. (American Sedan has specific engine rules and parts requirements)

Just a thought I've seen quite a few folks very disappointed when they find out their 383 aint legal... Unless they go to SPO or GT* and those guys are pretty serious cars..

 

I may be the odd man out on this but why not port and deck the factory heads? I'm very happy with my ancient 98' 806 heads ported by Advanced Induction. Phil decked the heads .075" (10.7:1 static compression) and the car made 410rwhp thru a fab 9", LS7 clutch, with an LS6 intake and a very similar cam to the one you mentioned above (228/232 - 59X/59X). My biggest take away from this setup is that the car really performs well under the curve. If budget is a big factor, it is worth considering.

 

Very curious to see where this goes....