Talk about stacking the deck.

[Stang's Bane]

I just ran across this

http://ls1tech.com/forums/showthread.php?t=907995

How blatant can they make the attempt to make their stuff shine and it still gets it's ass handed too it up top....

[Rampant]

I am not sure I totally agree with you.

Not just beacause I bought a set either. Just in the math.

Now I do agree that an optimized cam will shine in what ever it was designed for, but how else do you really do a specific apples to apples unless you do one thing at a time. Or you might as well just compare complete motor packages. I just want to know how they managed the valve cutouts in the pistons with 2 totally different valve layouts. Maybe the reason for the low compression.

Back to the math. If you use the 7000 as a shift point for a M6 you will see that 1-2 will drop you back to 4700 rpm where the TFS heads have a good advantage all the way too 6200 rpm. Then the 2-3 drops to 5100rpm and so on. I think it would be a close race with equal gears. Then again if you optimize your gearing it might be a different race.

The chart below see where each gear take you to after a shift. Not to sure if an auto would be as dramatic. For the street and autocross I'd go with the TFS curve. Peak only looks like it may be different by 15-20hp.

I would likely try to shift the TFS at 6500-6600 to get the best out of it.

RPM 1st Gear 2nd Gear 3rd Gear 4th Gear 5th Gear 6th Gear

4600 32 48 66 86 116 171
4700 33 49 67 88 118 175
4800 34 50 69 89 121 179
4900 34 51 70 91 123 182
5000 35 52 72 93 126 186
5100 36 53 73 95 128 190
5200 36 54 74 97 131 194
5300 37 55 76 99 133 197
5400 38 56 77 101 136 201
5500 38 58 79 102 138 205
5600 39 59 80 104 141 209
5700 40 60 82 106 143 212
5800 41 61 83 108 146 216
5900 41 62 85 110 148 220
6000 42 63 86 112 151 223
6100 43 64 87 114 153 227
6200 43 65 89 115 156 231
6300 44 66 90 117 159 235
6400 45 67 92 119 161 238
6500 45 68 93 121 164 242
6600 46 69 95 123 166 246
6700 47 70 96 125 169 249
6800 48 71 97 127 171 253
6900 48 72 99 128 174 257
7000 49 73 100 130 176 261

I am interested in hearing others thoughts.

Curious as to why the dislike for TFS? I know you guys disagree with Brians theory, but I have also seen that you respect that these heads have made reasonable power.

[Stang's Bane]

I am not sure I totally agree with you.

Not just beacause I bought a set either. Just in the math.

Now I do agree that an optimized cam will shine in what ever it was designed for, but how else do you really do a specific apples to apples unless you do one thing at a time. Or you might as well just compare complete motor packages. I just want to know how they managed the valve cutouts in the pistons with 2 totally different valve layouts. Maybe the reason for the low compression.

Back to the math. If you use the 7000 as a shift point for a M6 you will see that 1-2 will drop you back to 4700 rpm where the TFS heads have a good advantage all the way too 6200 rpm. Then the 2-3 drops to 5100rpm and so on. I think it would be a close race with equal gears. Then again if you optimize your gearing it might be a different race.

The chart below see where each gear take you to after a shift. Not to sure if an auto would be as dramatic. For the street and autocross I'd go with the TFS curve. Peak only looks like it may be different by 15-20hp.

I would likely try to shift the TFS at 6500-6600 to get the best out of it.

RPM 1st Gear 2nd Gear 3rd Gear 4th Gear 5th Gear 6th Gear

4600 32 48 66 86 116 171
4700 33 49 67 88 118 175
4800 34 50 69 89 121 179
4900 34 51 70 91 123 182
5000 35 52 72 93 126 186
5100 36 53 73 95 128 190
5200 36 54 74 97 131 194
5300 37 55 76 99 133 197
5400 38 56 77 101 136 201
5500 38 58 79 102 138 205
5600 39 59 80 104 141 209
5700 40 60 82 106 143 212
5800 41 61 83 108 146 216
5900 41 62 85 110 148 220
6000 42 63 86 112 151 223
6100 43 64 87 114 153 227
6200 43 65 89 115 156 231
6300 44 66 90 117 159 235
6400 45 67 92 119 161 238
6500 45 68 93 121 164 242
6600 46 69 95 123 166 246
6700 47 70 96 125 169 249
6800 48 71 97 127 171 253
6900 48 72 99 128 174 257
7000 49 73 100 130 176 261

I am interested in hearing others thoughts.

Curious as to why the dislike for TFS? I know you guys disagree with Brians theory, but I have also seen that you respect that these heads have made reasonable power.
I have never disputed the power that the big tfs cars make. There have been too many put over 600 to the tire on different dynos. Frankly my biggest problem was with Brian. He has gotten better, but for a while he was acting like the only heads on the market worth having were the TFS heads. He was on a God complex at one time and I am the type to hold a little of a grudge............:(

I have never noticed my car fallling that much between shifts, the 2-3 shift and the 3-4 shift always seem to me that they fall around 1000-1200 rpm or so..

I was looking at it as if shifting the ls7 car at 7K and the TFS car at 6500.

EDIT: I just figured out how to read your graph.............LOL Very interesting...

[Stang's Bane]

http://i278.photobucket.com/albums/kk118/TFStech/Tfs235LS7-1.jpg

Here is the graph for easier reference.

[Stang's Bane]

If you wound that trickflow car out to 7k, the results would not be nice. The car with the highest average HP in the used RPM range is going to be the fastest. That car falls off so bad after 6300, it would be getting pulled hard.


It is not a bad head, 3 things though..

1) I get tired of all of their chest thumping
2) You have to use a HUGE cam to get the big power
3) I like ls7 heads.........LOL:moon[1]::biggrinbo

[Rampant]

This is a handy little link.

http://www.f-body.org/gears/

Simple to use.

Pick your car, the redline and the gear ratio.

I used it originally to get an idea where I should shift my car in each gear. I used it with my dyno graph to see if there was any advantages to shifting a little later or earlier.

[Rampant]

I hear you on the God thing. I used to think the same thing about the AFR guys, but they made good power on the 402's.

I only picked the AllPros to be different and never really made any more power than the AFR guys did. I had higher flow numbers too.

Right now all I want is a running motor, I have done enough experimenting. It is to bad that they do not make a Harrop for the LS7 or I would have been all over it.:icon_bigg

[Rampant]

BTW the speed in gears are my set up. An M6 with 4.10 gears.

[Stang's Bane]

BTW the speed in gears are my set up. An M6 with 4.10 gears.

I thought they looked familiar. Same setup as me!!!

I just wanted to say that IMHO your car will do much better than this test. you will carry power past peak much, much better!!

If you can get that Harrop lined out and acting right, you will love your setup:icon22[1]

[Rampant]

Good point, the FAST 90 is supposed to be quite restrictive, where as I know at AWX they had done some flow testing with some ETP LS7 heads with a stock LS7 intake and were impressed with how little flow was lost through it vs no intake.

I believe they told me that it was quite different with the Fast intake.

Anyways, mine is very different and I have no idea how it will do. I have a wish list of somewhere in the 580+ rwhp range, but who knows. If I get that with a subtle idle and a clean smell from the catted exhaust all is good.

[SStrokerAce]

Kieth, your 100% correct on the cam difference. It's always easy to stack the deck when you want to, even if you don't know better.

A 3" difference in total induction length, along with taper and cross section changes are going to drastically change the camshaft requirements and the larger cross section, shorter runner length motor will have a distinct disadvantage with a overly large cam for the test.

Let's not mention the issues in the manufaturing of the LS7 head that "out of the box" will hurt it's performance vs. a well prepped head.

In the end that cam they used is not going to drive worth a rats ass in even a 440 cube motor and the appropriate cam for the LS7 would and make up a large part of that "deficit" in the TQ curve.

Honestly I think running the same cam in a LS7 vs a LS1/2/6 is about like doing that same test with a LT1 vs a Single Plane SBC.

Bret

[Stang's Bane]

That is why I asked him to try one of the other cams in the motor. It would be interesting to see what the results were from a cam that someone at least TRIED to design around the ls7 head.

[66duece]

Kieth, your 100% correct on the cam difference. It's always easy to stack the deck when you want to, even if you don't know better.

A 3" difference in total induction length, along with taper and cross section changes are going to drastically change the camshaft requirements and the larger cross section, shorter runner length motor will have a distinct disadvantage with a overly large cam for the test.

Let's not mention the issues in the manufaturing of the LS7 head that "out of the box" will hurt it's performance vs. a well prepped head.

Bretexcellent point..i'm not saying the TFS head is a bad product,but let's compare apples to apples here..

[Joe Mendelis]

"Trick Flow Tech" needs to tech his brain. 262@ .050 for an LS7 head? You would never need that much intake lobe. The LS7 has so much more overlap sensitivity than those things do as well.

You attribute the falling off at the top to the valvetrain? Where are your fuckin teeth?

The LS7 only made 680hp at the flywheel? STANDARD at that, not SAE. Run that through a 6 speed and gears, then correct it SAE and what kind of power would that be? I've had my LS7 heads with very minimal work make 632 at the tires with a hell of a lot smaller cam than that. This was 2 years ago!

Just a bunch of total Bull.

[Rampant]

Wow, tough crowd!

Since the rwhp vs flywheel was mentioned, what are the typical losses through an M6 and 10 bolt you have seen. I recall reading that W2W said with there testing they had only seen a range of 55-80hp lost and it was not the popular 15%.

I know from personal experience that going from a 10 bolt 3.73 to a 12 bolt 3.73 and a DOM DS cost me 9 rwhp. Then going from a 3.73 to a 4.10 cost me 4-5rwhp, but the car went way faster.

I am just curious as my break in and first pulls will be done on a an engine dyno. Though that will be with a carb, due to its ease of tuning and will not really represent what a Harrop will do.

Back on topic now, how would you say a proper comparison should be done? 2 all out motors, same cubes and designed specifically for each head and induction?
Personally it might have been more interesting if they had put a GMPP single plane on each of them, just to take the intake portion away from the equation, at least they are similar in design with the different port shapes.

The problem as I see it with cams is 3 different people could pick 3 different cams and make 3 different curves and that's for each head.

Am I wrong? Which is highly likely.:icon_bigg

[Stang's Bane]

Wow, tough crowd!

Since the rwhp vs flywheel was mentioned, what are the typical losses through an M6 and 10 bolt you have seen. I recall reading that W2W said with there testing they had only seen a range of 55-80hp lost and it was not the popular 15%.

I know from personal experience that going from a 10 bolt 3.73 to a 12 bolt 3.73 and a DOM DS cost me 9 rwhp. Then going from a 3.73 to a 4.10 cost me 4-5rwhp, but the car went way faster.

I am just curious as my break in and first pulls will be done on a an engine dyno. Though that will be with a carb, due to its ease of tuning and will not really represent what a Harrop will do.

Back on topic now, how would you say a proper comparison should be done? 2 all out motors, same cubes and designed specifically for each head and induction?
Personally it might have been more interesting if they had put a GMPP single plane on each of them, just to take the intake portion away from the equation, at least they are similar in design with the different port shapes.

The problem as I see it with cams is 3 different people could pick 3 different cams and make 3 different curves and that's for each head.

Am I wrong? Which is highly likely.:icon_bigg

You are exactly right. Using a more similiar intake would have helped with getting it closer to apples to apples. Like I said earlier though, I really don't think you can do an apples to apples comparison with heads this different.
It would be much easier to do a cam test than a head test IMHO.

As far as engine dyno to chassis dyno losses, the results are all over the place. I know of one guy that has had 3 differrent combinations in his corvette, and when all the drivetrain parameters are held at a constant, he reports a consistent 75 hp loss in the translation. Personally I don't feel it is a constant number or a fixed percentage. I think the more FWHP you make the higher the number loss will be but the percentage will drop the higher you move up the scale. Kind of a sliding descending percentage. Just my thoughts on the matter....

[Ed Curtis]

* yawn *

Typical of what the pimp site provides... That LS7 cylinder head and intake combination would be a better overall package if coupled with a MUCH better designed camshaft...

Oh... and what happened to the "can't go over .600" lift or the guides will wear" theory?

Ed

[Joe Mendelis]

* yawn *
Oh... and what happened to the "can't go over .600" lift or the guides will wear" theory?
Ed

Ed, are you saying there have actually been people to run over .600 lift without the guides wearing? I did my first set of LS7 heads in 2005 and they are still running somehow! that had over .600 lift. Maybe the engine will just explode?

[SStrokerAce]

You need to get out to Starbucks for your morning cup already mofo!

[wkmcd]

Not even close to a reasonable comparison. Take a cam that works for the TFS heads and thow the LS7 heads on? BS!!!

Tooley once again expanding the perimeter of his poop shooter. I hadn't heard much from him since he proved what a horses ass he was in my build thread. I could have gone a lot longer without hearing his BS.