300bhp/ton

The car is purly a toy and although could be driven at any time will mostly be used in the dry at weekends for pleasure.

Most will be street driving, but spirited. It will also see time at the 1/4 mile and race ciruits (track days).

As an everyday easily/affordable fuel I'm limited to what would be 91 octane in the US. An equiverlent to 93 octane is available but only from selected outlets and at premium price.

For preference I would probably aim to run on 91 octane.

Bob @ EPP recommended to aim for a 9.5:1 SCR, that's why I was looking at that.

I'll be running a FMIC and will aim for as high as boost as I can while retaining some form of safety margin on the fuel I've got. If I'm am a long way off with 91 octane then I'll bite the bullet as it where and step up to 93 octane.

My line of thinking was this if I run at the most boost I can safley muster with 'x' cam would swapping the cam out to something a little more OTT (not big necessarily just more wild shall we say ) offer me more in the way of HP and performance.

The cam I was considering is EPP's blower cam:

So can anyone offer a better cam profile than this?

By better, I mean more peroformance, more HP and faster on otherwise the same setup.

The car will be running a built auto, but on reflection I think I would want to be shifting somewhere between 6200-6400rpm. This would probably tie in better with the characteristics of the Ls6 intake manifold anyway.

It'll be running a 3500rpm stall. So I am quite happy too loose out on a little low end grunt for more mid/top end power. Because the only time it will see those rpms are on a light throttle. All WOT work will be mid/high range rpm.

What I want from the setup

-Wild
-Loud
-Aggressive
-OTT

And where possible lope (meaning idle). I want it to feel and sound bad *** as well as run it.

What I don't want

-Is mild or tame
-I certainly do not want like stock idle or driving, I want to know I'm driving something special.

Sorry if this sounds a little **** but if I'm having a h/c blown V8 I want it to feel like a h/c blown V8 not just a faster stock feeling car.

To give an idea of the character that I after, if I was staying n/a I would be going BIG stall, TSP Termintor race heads or similar and MS4 or Trex type cam.

I want the ability to intimidate even a Lambo Diablo while idling before leaving the stop lights.

Thanks for your help.

eamador11

Make it easy for yourself. if you get a supercharger, contact East Coast Supercharging and buy their custom SC cams. Why do the R&D when its already been done.

eamador11

Your already going the wrong direction, FI cams must be mild or your car will be in the shop for contant repairs instead of on the street. Plus your boost will need to be turned way down. thats no fun!

LSX-Racer

300bhp/ton

Why?

Well the EPP cam looks pretty interesting so why? And not that I'm wanting to compare to the sublime but top fuelers run big boost and wild cams, if it didn't work they wouldn't do it.

PREDATOR-Z

300bhp/ton

Stall: Wou'll want a lower str stall, in the 2.0 range max and pretty tight. Why so it applies this trq to the ground and not blowing through the verter.

Back to the cam:
230/236, .592/.602, 115lsa (this would be the highest I would go)
232/238, .595/.605, 115lsa
236/242, .595/.610, 115lsa
238/244, .605/.612, 115lsa

You are contradicting yourself on the specs: Shifts of 6400 max, means you need a cam that peaks at 6000>6100 max. Otherwise why leave all the power on the table.
That translates into a IVC of around 40 max

which brings us to the duration again. You cannot have this IVC and run huge durations. It is more sensible then to lower the duration and tighten the LSA. Which is what Aussies do.

This is why I mentionned that you first need to get your wants and needs strait.

The EPP cam will peak 6300+ so your shift desires are out the door.

So think about it again. Either mean, high reving (6700+) or else. You just can't have it all.

2000TransAmWS6

iTrader: (12)

jake, patrick,... thanks for responding to my overlap question.

Patrick G

iTrader: (14)

Mark, in general, people with Forced Induction motors don't want the maintenance and tuning hassles associated with larger cams and blowers, hence my recommendation for keeping overlap around 0 degrees at .050" (that's the general recommendation).

But in this application, 300hp/ton wants to take full advantage of all the power available to him, even if it means more maintenance and more tuning challenges. In this case, he can take full advantage of the extra overlap to make stronger top-end power. Also if running 9.0:1 SCR, then he'll want to bring his DCR up a little. This will make the cam choice a little unique too.

My recommendation?
230/244 .592/.612 114LSA +4

If you keep the idle in the 800-850 rpm range, it will lope very hard. A 900 rpm idle would have a chop to it. 9 degrees of overlap at .050" (closely centered over TDC for best all-around performance on boost).

PREDATOR-Z

This is what I thought.
But this 230/244 will have a IVC of 45, wouldn't that be beyond the range of 6400rpm shifts? That cam might peak around his shiftpoints don't you think?.

Patrick G

iTrader: (14)

With forced induction, the resonance ram tuning of the factory intake will no longer dictate what rpm the motor makes peak power and torque. The blower will do that. With a centrifical blower, I would expect peak power to occur at the maximum rpm the motor turns, regardless of cam chosen (to a certain point). If he turns it to only 6000 rpm, it will make peak power at 6000 rpm. If he turns it to 7000, it should make peak power at 7000. Again, this is all in general terms.

Personally, I prefer the Stealth approach to the Hammer approach. For my high SCR application, I'd probably run a stock '02 LS6 cam (to kill some DCR). The blower would make plenty of power, even with a 204/218 117.5LSA cam. But for our English friend, character is as important as power. The hammer approach will give him both.

300bhp/ton

Patrick, thanks that's some top notch info (as always ). Is that all the stats I'd need to give to a shop to grind the cam?

What lobes would you recommend for the above cam?

Yep that's bang on the money

300bhp/ton

I think Patricks explanation is better, but my line of thought was tkaing me down a different route of thinking.

I said shift around 6400rpm and you said a milder cam that peaked at 5800rpm would be better than a wilder one peaking at 6400rpm.

But how much HP would the wilder cam have been making at 5800rpm compared to the milder setup?

I mean if the wilder cam still within the confines of the 6400rpm shift point can still make more power than the milder setup then isn't it the better bet, even if you are still leaving HP on the table?

PREDATOR-Z

You seem to be set on what Patrick called the "Hammer" approach which is not how I would do things. As per my experience with blowers, unless it is a drag setup, then moderation and balance is the way to go.
In anycase it will be fun for awhile.

allngn_c5

iTrader: (3)

I think I agree with Predator. Less duration and lift on the intake and rely on the Supercharger more then the cam to get the air in, and open up the exhaust side with more lift and duration to get out all that exhaust quick,fast, and in a hurry. Either way you go you should be happy, but just don't overcam a FI setup because pullying for 14 and making 9 would suck. Especially if the cams overlap is the reason for the loss of those 5 lbs of boost. Go milder on the cam and wilder on the Blower.

orangeapeel

iTrader: (18)

So your getting cammed now! Excellent.

300bhp/ton