Louis

iTrader: (7)

I am sure that this post will create a lot of controversy, but, results are results. My C6 has been doing some hardcore Research and Development lately at LG Motorsports with Cylinder head and new camshaft development.

Back in July, I contacted the guys at ET Performance about their LS7 heads made to fit with the LS2 engines, more like made to fit the small bore of the LS2 and the L92 unlike its big brother, the LS7 that is made to work with 4.125 bores only. Craig and Cary at ET are excellent to work with. Being a phone call away speaks volumes of their operation.

These newly designed castings from ETP are quite interesting. They accept the LS7 valvetrain (Minus the Pushrod, thats a per basis deal, quite a bit longer than any LSx) And the LS7 intake/rails/injector setup.

2 months pass, we are in no rush as they are merely a research tool. September they arrive, brought to Atlanta for the SPEED Channel Forza Motorsport Showdown in which they were indeed on TV, as you will all find out in February the results of the show

The car has been put through the wringer. Current Mileage is only 800 since August However 400 was break in by me and 300 was pure pedal to the metal WOT at various racetracks in ATL.

Leakdown and Compression tests showed a clean bill of health ready to be the test bed for the next set of LGM Cams and heads/cam combos to terrorize the streets near you.

First setup was our executive cam, relatively calm, excellent daily driver cam. I do not have any cam only numbers because we are not interested in that at this time.

Now, back to the subject at hand- AFR 205s are a staple in this industry. They are the head to which every new kid on the block is compared to. So Why compare them to an LS7? apples and oranges you might say....

Well, we needed a baseline and I happened to have a set of used heads that were the exact same CC (stock LS2 CR) as the LS7s!

Great, lets do a baseline with those, then swap heads and see where we end up

Run 30 is AFR 205s and the G5xE cam. Run 34 is the 4" bore LS7s





So, thirsty for more results and data points, we swap cams to the proven G5x3 on a 112.

Again, 45 is AFR 205s and 39 is LS7s. The same rockers were used so we were not covering up any gains with simple rocker arm changes.






Ill let the results speak for themselves, however please take note that we are not finished with the LS7s just yet. They are an excellent head, but too much for a small cubic inch mill at this point. I have a few more cams to try, and we will go from there with more cubes.

Now, before you pass judgement, I have ET 225 small chambers on my personal camaro as well as several sets of ET 215s that we will be conducting more testing with to ease the pain of the winter months.

We were quite surprised by the results, or lack of improvement. We are not done just yet, but area under the curve is where we like to be

I would really like an LS7 with a port 10-20ccs smaller

Louis
LG Motorsports

Cobraeater

Interesting results!

Was the ls7 intake ported? Since the fast 90 tops out at 300cfm and the ls7 intake unported has been flowing 330-340cfm and etp 4" ls7 heads flow close to 350cfm I have to wonder how the AFR 205's were able to compete with ETP's heads.

Any plans to test some stock/ported l92 heads and l76 intake on your car?

Louis

iTrader: (7)

Yes

As for the AFRs keeping up, Im still sorting through the data before I open my mouth. The LS7 intake was not ported. It was stock out of the box.

ls1408cp

iTrader: (37)

How hard were you spining the motor? Looks like it would have made power way up top.

Nate_Taufer

iTrader: (1)

Eh. Looks like the graphs cross both start to downhill after peak at close to the same results.

For the sake of these tests I think the cam is in no way going to be optimized for the heads. A G5X3? Come on Louis, I figured you of all people would be more for a tighter lsa and a much bigger exhaust split on something of this nature. The LS7 head has a longer runner and you can't expect the same power with the same cam. This is apples to rotten oranges comparison.

NAte

Bring the Noise

My thoughts are in a similar area as Nate's....
Toss in one of Katech's LS7 Torquers and see what comes out on the dyno sheet...

You'll probably be suprised at what the increase in exhaust lobe duration does for the LS7/L92 style heads even on a 364 powerplant.

Blown04Z06

id like to see the results on a 403/408 which is where these heads should shine. i dont think the 364 is enough cube for the 4" LS7 head and intake, nor is that cam enough cam.

small runner/chamber 205 AFR is the right head for the 364ci motor and that particular cam.

im sure not everything is equal here at all. DCR/SCR werent equal. chamber sizes arent equal, nor were runner size. this is a mismatched set of parts being compared to each other.

gator's 99TA

iTrader: (2)

glad to see real results. very cool louis. nice to see someone do some real R&D instead of just showing up hype to sell a particular product. keep us updated.

Patrick G

iTrader: (14)

Very interesting results. The ETP LS7 heads have been on my radar for use on a future large CID build. I'm shocked that they did not perform well with the 6.0L. I don't agree about the cam not being optimized skewing the results this much...a more optimized cam for the ET heads would have shown more gains above 6000. The torque losses in the mid-range are shocking. I guess the AFR 205s are sized right for the smaller 5.7-6.0L motors, whereas the LS7 heads will not excel until displacement exceeds 400 cubic inches.

Thanks for the back to back testing Louis!

Louis

iTrader: (7)

The ETP exhaust is much better than the standard GM LS7. You guys have no clue what we are running for splits on the LS7 stuff we have now, so please, I of all people am well aware of what cam will do what, The G5x1 is a 4* split, X3 is an 8* split.

DCR and SCR were IDENTICAL on both tests. Same compression, same rocker arm ratio. Give me a little credit guys Im the one who spent 3000$ + 3 days of labor for one, sometimes 2 of my techs to make this happen. I left nothing out nor unturned.

Phil99vette

iTrader: (11)

VERY Good post, love back to back testing like this...
Just a couple of things I noticed....
ETP LS7 heads:
Average Intake flow: 268
Average Exhaust flow: 181
I/E Efficiency: 68%

AFR 205 Heads:
Average Intake flow: 234
Average Exhaust flow: 188
I/E Efficiency: 80%

Its almost like the LS7 heads need more duration on the exhaust. If the AFRs like 8 degrees with 80% than I wonder if the LS7 need 12-16 degrees more on the exhaust???

SideStep

WKMCD

iTrader: (2)

Makes sense.

MeentSS02

iTrader: (11)

Thank you for this data. Definitely keep us updated on what these heads do on larger displacement motors...I'd also like to see what you guys come up with for the ETP cathedral ports vs. the AFRs.

JL ws-6

iTrader: (50)

I'd be curious how a set of the et 240 would have compared to the afr, only because it would take some of the intake questions out of the picture.

Good results though.... keep at it, we are all watching.

ATVracr

iTrader: (5)

I did a back to back with AFR 225's and ET 225's ... nothing changed but the heads and the ET's picked up 15 Hp.

We also did it the other way with my old cam (Et 1st ,AFR 2nd and the AFR's lost 40hp)

Next cam will be more ET head friendly like the 1st one.

Phil99vette

iTrader: (11)

I think cams are going to change pretty drastically with the I/E efficiency changing as much as it is with the big flowing intake/head combos.

Louis

iTrader: (7)

Thanks guys, were not coming to any conclusions yet and the testing is ongoing. I have another cam to try today if my techs can make it happen. We work late nights and long hours to do this testing which ensures that customers cars are the top priority.

I think that had we not done the AFR baseline, we would be happy with that. 500/450 is a KILLER package with the uniqueness of a an LS7 topend.

You have to admit though, 470 rwtq out of a LS2 is pretty amazing.

If the camswap goes as planned, we will continue with the LS7s. Change one thing at a time, keep variables to a minimum.

I would like to mill them for more compression, both sets of heads, but 11:1 is a common ground for pump gas, street driven cars around the world.

Louis

Paynful

Last time a checked a large port, short runner intake will make less torque than a small port, longer runner intake. All other components the same...

Inspector12

iTrader: (29)

Your lying you didn't go to Atlanta LOL! Good testing results I do have one little question because I haven't looked seriously at the ETP LS7 heads so I don't know, but what intake was used cause I know that the GM LS7 take a LS7 intake etc... and the AFR's utilize a LS1/6/2 intake manifold runner design so I was just wondering if these ETP LS7's were made with this type of intake runner or did you use different intakes or what? I was thinking this little difference might make a difference in the results also just a thought. On another note how does the car look currently? Still in the race suit?
Jeff