Copperhead

So I'm building a 92 Formula for a Time Attack/Track Day car, will have an alum-head 350 or 383 SBC w/ T56 and 3.70 9-bolt. What cam might you guys suggest for this combo? I ran a dead stock Player's Camaro last year and found it perfect, except for the missing 200 or so hp. I have an LS1 for rebuild but no accessories or trans, whereas I HAVE everything for the SBC - - LT1 T56, headers, accessories, hi-flow TPI stuff, chip burning stuff, etc - - so it just makes more sense to go SBC. At this point in time I feel that 400-450 fwhp will fulfill my need for speed - - at least til I learn to DRIVE!!!

Also looking for many good roadrace parts for same, incl Canton pan, alum heads, lightweight stuff, race seat, rollcage, etc.

All suggestions/sale items welcome. Located in Calgary AB.

Orr89RocZ

iTrader: (20)

Road race is broad powerband across wide rpm range. TPI doesnt really give you this. A shorter runner intake would help.

Else i'd suggest something with 10-12 deg exhaust split from the intake to extend the powerband past peak. Thats just my opinion. You need to be running from around peak torque rpm to well beyond peak hp rpm, and this is a broad range. Wide duration split will keep hp hanging on well after peak. Tighter LSA gives low to mid range torque. Combination of the 2 should give a broad powerband. Similar to the cam I had in my 383 HSR. Flat torque curve and wide HP curve.

Now with TPI being rpm limited, the other way to make a broad hp curve is to just overcam it like in circle track racing setups. They run 10-15 deg higher duration than normally run for peak hp rpm the heads/intake will support, but this extends the hp curve well beyond peak to allow for broader rpm range. This may give up low end but those cars typically run in a certain rpm band and dont really worry about too much mid and low range power.

A custom grind would be best in this application...shelf grinds dont really have the characteristics for a road race application.

Copperhead

I find torque pretty handy coming out of the corners, esp to recover speed quickly if you brake too hard going in. That's one reason I felt TPI would work well. The 305 just didn't pull much from 50-120 mph and wasn't ANY fun on the long straights. Barely pass anyone.

Orr89RocZ

iTrader: (20)

Long straights favor HP and making that with TPI is abit tough. Can be done but you should look into porting that intake and runner setup as much as possible to help feed the higher rpms

Copperhead

Starting with an Edelbrock hi-flow lower intake, and a custom-built siamesed runner setup out of the Gale Banks shop long ago . . .

TTOP350

iTrader: (8)

build a 400 plus CI motor and use a short runner EFI manifold.That will build your TQ and help you haul azz down the back straits..

irocarter

iTrader: (1)

anyone ever tried Comp "Camquest" program? just wondered if it was very accurate in deciding a cam.

Orr89RocZ

iTrader: (20)

It picks comp cams shelf grinds from the last time I used it. Wasnt impressed. You can do that yourself just by looking at the catalog and rpm ranges....

brodysZ28

I used the camquest program and it pretty much recommended the same cam most guys on here thought would work well. XR288HR.

TTOP350

iTrader: (8)

I had comp pick me out a cam 4 my last build and it was rather small. Even smaller than what I had!
I told them what I was looking for as far as lift, dur and lobe sep, after several Emails back an forth they got something thats close to what i was looking for. They said "sounds like you want a race car on the street".. Nope, I want a street car that runs like a race car!! The cam I ended up with is very nice. I drove it all over everywhere (3,000 miles in a month or 2)and its not even tuned yet..

Anti-Venom

For what he's looking for he's idealy going to need to build something with some qubes. I agree. A 383-400 would give him the 400-450hp he's looking for. And would be able to keep a cam conservatively around 220ish duration, 112-113 lsa and .050 lift with decent heads. Would idle nice with ton's of torque. You'll be looking for wider tires next.

A 350 motor your going to have to really turn it to get 450hp with alot more cam and sacrifice a bit of torque with a choppier idle.

Copperhead

Thanks for the replies. We've decided to go with a 383 with 4-bolt main kit, Patriot aluminum heads and a Comp 280XFI HR13 roller cam. Comp recommends their Magnum or Pro Magnum roller rockers; my builder was thinking of stainless. Patriot can supply Scorpions or Harland-Sharp at a good price. Thoughts for best longevity in roadrace application?

Orr89RocZ

iTrader: (20)

make sure you run stiff springs for that cam! 155lbs seat 400 open like the patriot extreme gold springs will work more than likely but those cams are hard on valvetrain.

Scorpions are nice rockers, they have been used on dirt track/circle track cars with good success. Comp pro mags in steel are stronger tho.

Copperhead

Told Patriot the cam specs, upgrade required to dual springs.

Scorps thru Patriot are about $230, Pro Magnums are $320. I'd also like to stick with OEM valve covers, I'm all about the factory look.

SiCkRs

iTrader: (6)

Since you wanna use the tpi you should give dyno don a pm he has a 400rwhp tpi that way he gives you some pointers on whats best to do

Orr89RocZ

iTrader: (20)

The pro mag rockers likely wont clear the stock OEM covers. Regular magnums will but they arent full roller and not as strong overall. Scorpions I'm not sure but the set I have are likely similar and I doubt they will clear stock covers as well.

theNMBR27

I'm also unimpressed with comp, took them two tries just to ship the cam I ordered. Interested in how this turns out.