what HP from a Heads and Cam M6 car?

Just bear with me, I'll explain more later...

 

Somewhere around 460hp at flywheel. The conversion factor is not exact but, more of a good guess.

For N/A I use 11.3 * MAF(lb/min) = Flywheel hp. The conversion factor could be slightly higher or lower though.

I read about the factor being 11.5 or so a while back but, don't remember where or how that number was calculated.

 

Air filters and different lids change the number a little but I would guess if it has the screen it is around 380-390rwhp and 400-410 if the screen is out. If its an aftermarket recalibrated MAF who knows..

 

Thanks guys, a few more responses and I'll explain why I'm asking.

You guys might be very surprised of what I might have found....

Hey NoGo (Kevin) any thoughts on this....

Bill

 

Anymore?

 

Anyone else? Kevin, NoGo?

 

Spill the beans

 

DAMN!

 

You have to know the volumetric efficiency of the motor at peak HP, and some cylinder geometry to do a design calc as to how much power you think it makes.

Power = PLAN

P = Cylnder Pressure
L = Length of Stroke
A = Area of Bore
N = Number of puts (rpm basically)

However, a pretty simple rule of thump has always been 10 * MAF.

41 * 10 = 410 RWHP

It is not exact, but it is usually in the ballpark.

So whadja find out?

 

Ok, now that Kevin, (NoGo) has replied, I will spill the beans. So go grab a Coke or Pepsi.

This is sorta a tuning/internal engine issue, so I hope this is posted in the right section.

A few weeks ago, I had a guy call me up asking for me to tune his car, a 2001 Camaro SS M6. I said sure, I can do it, I have the full version of HP Tuner for all LS1 F-Bodys. I told him to tell me the history of his car.

Last March, he bought a lot of parts:

Patriot Performance Stage 2 (LS6 Style) Heads (STD combusion chamber)
TR 224 112lsa cam
SLP LT with cats
SLP Loudmouth Catback
Lid

He had LS1 Speed install and tune his car and gave him a print out that showed 393 HP & 385TQ with an A/F about 12.8-13.0 -1. I said a little on the low side for power but not by much. He said and was told by LS1 Speed that his numbers were down some because his compression ratio is lower due to those heads, ok, sounds about right.

He drives the car for about 2,000 miles or so and all of a sudden his car loses some power and is making some weird noises. I was told it got so bad he didn't want to drive it anymore because he didn't want to damage it.

Bear with me, I'm going somewhere with this......

The owner of the car decided to get it checked out and they found out that a spring broke and did damage to the head.

If you guys remember, Patriot Performance was having trouble with their heads dropping valves, leaking, & breaking springs 5-8 months ago.

So the guy calls up PP and told them the story about his car. PP decided to make it 'right' and gave him a 'new' pair at no cost. But this time, he got the LS6 style heads with the smaller chamber so the CR will be about 11.0-1.

The car owner decided, since it's all tore down, he went with a bigger cam TSP 231 237 & underdrive pulley.

So with that combo, you would think the car should put done at least 430HP at the wheels right?

NOPE! The best that I could do for him was 404HP & 365TQ!!!

He was getting max timing (28) and his A/F was at 12.8-1.

I have tuned a few dozen cars now and when you dyno tune, you watch/log data to see whats going on. On his car, with a stock MAF with screen, I was getting about 40-41 lbs/Min of air from around 5,400 rpms on up. I have seen this with my own car that was making 412 at the wheels and others as well. I have tuned other cars that were close to 450 RWHP and their MAF reported about 43-45 lbs/Min. The more HP you make the more air you need.

Granted, it was a hot day and the humidity was a little high, but that wouldn't affect it that much.

So where am I going with all this? Personally, I don't think he got the heads he was suppose to get. I checked for a casting number, PP ground it off and stamped "Patriot" on one and "LS6" on the other. So who knows....

He never got a flow sheet with his "brand new" heads, so all we know they could just have a half azzed port job on it.

From talking to other people in the know about this (one is a dyno builder/tuner), 40-41lbs/Min from the MAF equals about 400-410 at the wheels.

There is one other possiblity, he might not have the cam that he is suppose to, but what are the chances of this. I haven't asked him if he got a cam card with his TSP 231 237.

What do you guys think?

 

There are a couple things you can do to verifiy if somebody has actually improved their setup. The amount of air that the setup is moving is one of them. I keep an a-tap log of all the cars that we have had on the dyno, and one of the primary things that I compare for before and after build results is the airflow of the engine.

Naturally, the chief component of making power is how much air you are moving into the engine. We see this as the MAF report. This in turn is a direct representation of the Volumetric Efficiency of the motor. Just look on the web and you will find a description of volumetric effiency.

An easy way to see if somebody has improved their setup is to make a volumetric efficiency calculation prior to disassembly then one after the new setup goes in. Volumetric efficiency should provide a near mirror of the torque that the motor will provide. If the VE of motor has not improved then the setup has not improved. If the VE has gone up, but the power has not gone up then there is something else coming into play.

This is a very useful tool especially when builds go from a T56 to a TH-400. The dyno may report a lower number with the newer setup, but being the VE has actually increased we know that it is just the new driveline that is sapping the power and we have actually made power gains.

JMO

 

The car in question is my car. Bill TSP did send me a spec card for the cam. This thing about the heads are starting to concern me a little now.
Also to clear some things up, the springs in my old heads did not fail. The seat in the heads are the ones that failed causing me to bend a valve.
Everyone else that has PP heads do you guys have any casting #'s on your heads or is it just the Patroit logo and LS6 heads on each side?

 

Also another thing that I should add is that I added a ported TB and Underdrive Pulley when I put on the new heads and went with the bigger cam. So something is definately wrong. Anybody?

 

Ben,

Thanks for reading this, told ya I was on it! Also, thanks for clearing it up for me about you damaged heads... Hope your trip went we, pm me if you have any concerns....

Bill

 

Bill,

I think I'm gonna put the 224 cam back in along with my stock heads and sell my PP heads and get some AS or TEA. The 231/237 bucks to much at low RPM and is a little more then I wanted in a daily driver.
The trip went well, but it rained most of the time.
I think I'm also going to put in a 12 bolt with some 4.10's.

 

I have the PP ls6's on my car. And just installed a set on my freinds car. Same thing with the "Casting numbers" on the side of the heads. If you looked at them before you installed them you should have seen on the bottom side of the intake runners 6.0 cast into the heads. If you do pull them off take a look. If it is not there I would give Terry a call.

Brad

 

My older PP LS6 'style' heads dont even say patriot anywhere but the all the casting numbers are ground off except the 6.0L on the bottom.

For a reference, with a 224 112+4 XER cam, FLP headers, hooker exh, March pulley, LS6 intake, 59cc PP LS6 heads, TH350, 9" ford w/3.70 gears and dynoing with ET streets I did 399 SAE with an unlocked converter going through the exhaust. Car runs 93mph in the 1/8 at around 3470 raceweight in 3100' DA weather so the dyno is pretty close. Through a 10 bolt M6 it would probably dyno 420 or so with the 224 cam..

I also dynod it on a nitrous tune, 26 degrees of timing down to 23 at torque peak so it would probably make a little more with more timing. Maybe try swapping the cam before you bail out on the heads, with the higher compression the car drives pretty nice with a 224/581/112.

 

Ummmm....you might want to see how the 231/237 does with the 4.10s...as far as the bucking goes. You might decide to keep it!

joel

*** when does it buck??

 

Yep, 4.10's will definately take care of that Buckin problem!

Brad