Cam choice for bi-turbo LS1 high rev?

[BoxerSix]

For every half dozen Porsche motors I build there comes a good ol v8. Seriously though, I'm working on a long term street legal GTP project for myself(and it's not a Pontiac either ). I'm building a bi-turbo(3076r's) LS1 to move the car and need a good cam for this motor. Midrange to top end punch is what I need, the motor will be swung into the early 7000rpm range, and must breath for roughly 750 crank hp(~90lb/min) on stock sized valves. LS1 heads and LS1 intake manifold. Aside from that, the slate is clean to write.

I've built LS1's in the past but again, it's a rarity compared to my main field and look for other builders' (fact based) opinions on what they like to use(or have used) in similar builds. I'm not normally a V8 guy, but the power-gain simplicity compared to a 3.6L boxer motor is just too good to resist

Appreciate the feedback...

-Adam @ KTA/ER

[intern8tion9l]

non-pontiac gtp......hmmmmmm

[crazybrew609]

i would suggest trying to get a hold of howard over at redline motorsports... he only builds v8's and is actually doing a twin turbo LS1 himself so he might have a good idea about cam spec's or cam choice

[BoxerSix]

Originally Posted by intern8tion9l

non-pontiac gtp......hmmmmmm

Think Lemans 24 Hours

Howard @ Redline you say. I'll give him a shout. Thanks for the tip....

[Captain Moai]

What's the spec on the current cam? Lift? Duration? Lobe Centerlines? What pressure ratio are you intending to run? What RPM range are you looking to primarily use? Changing the rocker ratio? What size turbochargers are you using? Is the block modified or are you using standard size internals? What octane do you plan on using?

these are the things I want to know.

[BoxerSix]

Originally Posted by Moai

What's the spec on the current cam? Lift? Duration? Lobe Centerlines? What pressure ratio are you intending to run? What RPM range are you looking to primarily use? Changing the rocker ratio? What size turbochargers are you using? Is the block modified or are you using standard size internals? What octane do you plan on using?

these are the things I want to know.

Ah who the f**K am I kidding. I've got 2-3 years before this will be finished and Justin is bound to spill his guts on it anyway eventually I'm building a street legal replica of the GTP Porsche 962. Overall cost is expected ~$65K from the body manufacturer (Body is $~25K) but I'm not using a host of race specific parts (like the GT Brembo Endurance calipers @ $4500 a pair)....This is actually a kit car that I've been designing for the past 3 years with patents and paperwork along side it. Should compete along side the Ultimas and Factory Five kit cars out there.

Here's a brief overview of the drive train. Note that this motor is nothing more than a pile of parts right now that I'm collecting. Things may change down the road before I actually begin the assembly...

-1999 LS1 block, heads, intake manifold, and throttle body
-Stock bore and stroke
-Stock heads(cc'ed) and ports
-Internals: Manley rods, Mahle pistons(ceramic coated 8.5:1 CR), Eagle crank, Clevite bearings, REV stainless valves(stock size, ceramic coated), Crane pushrods and roller rockers, main cap block girdle, etc
-Wolf EMS
-RPM range use.....idle to 7200rpm. It's going to be built as endurance track car, legal for the road. The 3500-6500 range for the majority of it's use.
-Dry sump oiling system(one-off setup)
-Multi stage methanol injection(one-off setup)
-Twin plate Tilton 5.5" clutch with flexplate. No "true" flywheel so to say. Mated to a G5052 transaxle (ME-RWD configuration). The motor is going to be very "rev happy"
-No current camshaft. Stock LS1 cam profile doesn't suit this application. Rocker ratio to remain stock If possible. Midrange to top end as stated. That car is not going to be meant for the super tight twisties and I don't ever plan on going on daily errands with it either..

The turbo setup is a bit complicated. The manifolds and complete setup I'm designing in Solidworks and Cosmos right now. It was originally slated for a single GT4094R as the car was going to replicate the IMSA 956 but that changed. The car is estimated to come in near~2200 lbs total dry curb. If that's the case I'm setting up with twin 3076R's @ about 2.38PR......looking for ~700-750 hp and 650-700 ftlbs. If I cut A/C and a host of other useless crap it may duck into the 19-2000 lb range at which point I'll dropping to 2876r's @ 2.20PR and hope to get in the 650 range for both plots. I'm a Garrett dist and might just buy both sets of spools to run them and see what I prefer. Wolf EMS to control it. Exhaust is slated to be full titanium for weight savings and have complete 100cell cats(Gemballa 996 Turbo units).

Yada yada yada.....did I miss anything.

Now back to that camshaft. Like I was saying I can build motors all day long but I'm a bit new to the tuning aspect of the LS1 series motor and like hearing feedback from those who have been there before. Plus i just enjoy learning more crap

Thanks

-Adam

[mikecentola]

Wow that sounds awesome!

[BoxerSix]

Originally Posted by mikecentola

Wow that sounds awesome!

I'd bet most on this forum don't know what a 962 or 956 is and have to go source photos online so I'll pull one good one up here. This is a long tail 962C converted to a road car via Dauer. Overall cost is about $1.2 Million when all said and done..

962.com :: The Finest in Motorsport

It's a very frustrating project right now as I need to build the financial backing to purchase a body outright. Without the body I cannot begin fabricating the tube chassis. I already designed the suspension components, drivetrain, undertray, and airfoils but need that body to get a move on this. Front and rear clips, side pods, doors, and roof/windshield frame in glass are $22K---total front windscreen and side glass in polycarbonate add another $1500, then shipping from good old California...

She sure isn't going to be cheap.

Anyway I don't want to get too off topic here in this post.........Camshaft stuff

[crazybrew609]

this thing is gunna be nuts... i'm guessing it's not gunna be completel C/F tho like the one in the pic.. still if it's gunna have huge rubber like that out back it's gunna be nasty

[Shawn96VR-4]

That thing is SICK looking. I remember you doing that Porsche out of the Dodge and it was amazing look. The only issue is if you plan to sell. I think you took a bath on that car

[Celtic1982citleC]

The Dodge Avenger turned 911 was pretty god damn amazing. He ended up parting out the car and doing alright so far as I remember.

[Shawn96VR-4]

^^^
Yep. It was absolutely sick. Hard to sell anything to the crowd around here.