BryanPendleton

I am been searching for some basic engine modifications for my LS1 C5, and I must say I am sick of the "******* comparisons". 80% of the time the only information reported is peak horsepower and torque, as if they drive their car at one engine speed. I even found a couple magazines with dyno plots that did not start until 5000 rpm. Needless to say it is frustrating.

My goals are simple, having been down the "high strung motor" route on a different platform, I am simply looking for simple OE-like reliability setup with a goal to maintain or increase torque in the 3000-6000 rpm range as that is where I am running while on the road racing tracks (no drag racing here). So what do I mean by OE-like reliability? My plan is to leave the short block untouched. Not even sure I care to mess with the cylinder heads, unless there is a GM OE head that would meet my goals. Simple, mild cams and your typical bolt-ons.



My problem is, I don't trust anyone when it comes to cars, and don't care to go in blind, so without seeing the actual test data myself, I do not have the confidence to pull the trigger, particularly on modifications that can significantly change the VE of the motor and risk loosing engine output in the 3000-6000 rpm range.

So does anyone have any recommendations that are backed by solid data?

Intake Manifold? (LS6, FAST78, FAST90 FAST92, etc?)

Cams? (Z06, GM Hot Cam, ASA, others?)

Cylinder heads? (GM?)

Intakes (Halltech, etc?)

Recommend Tuners in Houston area?

bosco022

You don't have to look much farther than the combination used in the SCCA GTA type cars for good, torquey reliable road race power.

The formula is pretty simple:

* at least the scavenge type dry sump system as developed by ARE, AVIAID and others. Full dry sump would be even better. Some have gotten away with the batwing type pan on the LS6 motors for many track hours on stock motors, but I think it is a crap shoot when you you are on grippy slicks with upgraded suspensions.


* GMPP ASA hot cam or similar, not necessary to go over 550 lift or so
* LS6 intake
* 243 heads with a good competition valve job (we use advanced induction) the 241 heads will make 15-20 less HP, but are OK.
* better valve springs
* stock rockers with the comp cams trunion upgrade
* for the C5 platform: the LG Motorsports long tube headers
* good ECU tune

ARP rod bolts would be a good addition as well as upgraded timing chain.

This set up can make 460-470 hp at the flywheel, about 30 more HP than the fine performing ASA Lingenfelter motors. These will pull hard from 3500 to 6500. For excellent reliability, shift at 6500.

Certainly there are combinations that will make more power, but this is a proven budget road race combination.

If you haven't done safety, suspension, brakes, cooling....do that first.

BryanPendleton

Excellent information. Did not think of looking to the various race organizations and seeing how the C5's were being prepared. I assume the engines are under some restrictions within GTA class and others.

Thank you,

Gering

bosco022: Great info, thanks.

bosco022

The SCCA/Crane Cams V8 StockCar GTA cars have several engine combinations to choose from including the older small block chevy carbureted motors, the base Lingenfelter type LS1's, and the upgraded LS1 as noted above.

Our LS1 cars with less than 500 HP have run laps as fast as 1:57 at Daytona and 180 mph in the trioval in a GTA car and 2:14-2:16 laps at Sebring.

Below is our LS1 Camaro it has to run in the SCCA SPO class because of the wing but otherwise is really just a GTA Camaro.

BossV8

Very intesresting.

bosco022

Below is our tube frame C6 Corvette, which is really just a custom built GTA type car with the C6 body. Motor is just an all forged, dry sump, nearly stock LS6.....makes less than 500 flywheel HP. Weighs about 2530 # without driver. G Force dog box 4 speed and 9" ford rear end.

The Monte Carlo stock car in the pic is the same car as the Camaro before we re-bodied it with the Howe body. Has a carbureted LS1.
Also about 2500# without driver and ballast.

both have motors that are similar to what I outlined above and are strong performers.

AU N EGL

Houston? England Green

He is on the forum here.

FASTFATBOY

I built at ls1 bottom end with ARP bolts, Mahle pistons, LS6 topend off a 2003 Z06, makes 385 to the wheels, drives as stock, gets 30 mpg if you stay near the 70mph limit.

As far as tuners, call Geoff Skinner in Baton Rouge La. He owns EPS, Engine Power Systems.

Will do almost 140 mph down the front stretch at Roebling Road weighing almost 4000 lbs with an instructor in the car.

I can run Roebling entirely in 4th gear(with a 3.42 in the rear), never touch the shifter as the car makes VERY good bottom/midrange torque.

Here is an incar at Roebling


In a 3300 lb vette this engine would fly.

Addicted to track

What do you mean by "good competition valve job" Bosco? Is that a 3 angle grind??

Frans96ss

Give Late Model Racecraft a call. They are in houston.

crimlwC6

So is the 15 to 20 hp difference between the 241 v. 243 heads after they have both been ported? Trying to figure out cost/benefit ratio of porting my stock LS1 heads and keeping motor vs. buying a whole motor (LS3 crate, MTI LS1, etc).
Thanks for the great info!

bosco022

I was referring to," before porting". 241 heads are still very good heads, just not as good as the 243's. Advanced Induction (and others) has a port and chamber work option for the 241's that comes very close to ported 243's. Considering you can buy good used 241's for about 100 bucks, something worth considering.

crimlwC6

Cool. Thanks!