JEB99TA

iTrader: (32)

You may have already seen this, but, if you're like me, I had not known this until today. I see a lot of people buying the 90/90 setups for cars around or under 400/RWHP/RWTQ. It looks like a waste of money after seeing this. The LS6 intake outperformed in low and mid-range hands-down over the 90/90 setup. Not a whole lot was gained up top, either.

To think I was about to spend all that money to sacrifice low and mid-range power for a little up top above 6000 rpm. That's where my A4 shift points are set. I guess my $1,400 will go towards the 100-500 progressively controlled Direct Port setup with my LS6 Intake. Of course, if you need it up top more than you need power down low or in the mid-range ... with a larger bore engine ... guess you need the 90/90 setup.



http://www.gearchatter.com/viewtopic10974.php

Louie83

iTrader: (3)

Good find, very interesting. I'm pretty surprised by the results.

02RedHawk

iTrader: (17)

To make sure no-one freaks out, those were engine dynos. Even the best 432hp peak equates to only 375rwhp (at best on an M6). On top of that, this was with stock unported *LS1* heads.

I would say that for cars *UNDER* 400rwhp its a waste. 400rwhp and above will likely benefit greatly from the 90/90 setup, especially if you have higher than stock shift points.

Cgillies86

iTrader: (1)

If the LS6 intake manifold had a ported throttle body, I bet the peak would of been a bit closer to the peak of the LSX.

BADFNZ

iTrader: (19)

And I bet if the FAST intake was ported, which everyone does, the numbers would have been even higher.

Redneck Z

iTrader: (3)

If the FAST had been ported on the 375 rwhp test cars, then the LS6 would have ruled the low and mid range to an even greater extent.

SouthFL.02.SS

TPIS has addressed this issue. It's not so much the TB being the limitation of the LS6, but the size of the opening.

http://www.tpis.com/index.php?module...+Throttle+Body

BADFNZ

iTrader: (19)

Good thing our redline isn't at 3500.

SVC707

iTrader: (33)

heres what i have to say... if you have the funds then go for it.. i just orderd mine if i gain then i do if not oh well... ill be doing heads and a new cam later this year.. ill gain from it sooner or later

and ill admit i NEVER thought id be spending this much coin on an intake and tb.. even my friends were talking shiet said i they thought id never "waste" my money on a FAST 90

Louie83

iTrader: (3)

I agree. I will be going heads eventually so I still plan on going 90/90, I was just impressed with how well the LS6 did.

Photochop

iTrader: (74)

Interesting results, good find.

If the test engine had a larger cam and well ported heads on it the outcome would have been closer OR if the engine was of larger displacement (383" or bigger) the FAST setup would have had the upper hand.

Wish the FAST intakes were cheaper

JEB99TA

iTrader: (32)

On a larger bore motor topend might show larger numbers, IMO. The 90/90 prob wouldn't be a restriction until over 1000 HP anyway (just my opinion), so, I doubt you'd see any difference at all by porting the already more-than-ample 90mm TB unless you were over that power level.

Low-midrange on a 346/347 cube would prob even lose more down low/midrange from porting the 90mm.

The whole point for me posting this was to address the 400 RWHP range on a mildly modified LS1. The differences in various intakes was my point on this power/motor environment ... not the what-if's. I think we all know the 90mm/90mm is the absolute best way to go on larger bore motors making moprepower, however, you'd still be giving up power/torque down low. Then, again, on a 402/408+ stroker, who would really care unless you're trying to loft your car into a vertical wheelstand. That's impressive but doesn't win races.

I appreciate everyone who has responded so far. Keep it coming.

JEB99TA

iTrader: (32)

I think BADFNZ has a point about the Intake being ported. I went back and re-read the post and he was speaking more to the Intake itself, not the TB. My apologies BADFNZ. I'll read responses much more carefully, going forward.

oange ss

iTrader: (50)

not too sure about those tests, it looks a similar test done by Hot Rod or CHP or another mag, with similar results....all tests were done using stock pcm with no tuning, every one knows to get the most out of a mod tuning is a must. I believe the results would be different if each combo was tuned for the specific mod, but maybe leave timing alone for comparison sake.....

BigDaddyBry

iTrader: (15)

This looks like the article that appeared in Street Thunder magazine (same types of tests).
http://www.tpis.com/plog/index.php?o...Id=14&blogId=1

Here are a couple other discussions on this article:
https://ls1tech.com/forums/generation-iii-external-engine/432100-ls6-intake-vs-fast-lsx.html
https://ls1tech.com/forums/generation-iii-external-engine/436779-tpis-oval-ls6-throttle-body.html

Another person posted a scan of the article, not good quality, but just FYI:
http://www.eadperformance.com/intakearticle/

I like these tests for another reason: there has been much negativity with respect to the LS2 intake, but with no supporting facts. You would hear "the LS2 flows worse than the LS6" or "you lose hp with the LS2 intake", then you would ask for the data, and the response would be "oh, it's over in the dyno section". When you search the dyno section, it's someone stating it but not supporting it.

JEB99TA

iTrader: (32)

They looked like pretty hard facts supported by dyno charts ... make sure you read the entire thread and you'll see the charts.

Out1aw

iTrader: (1)

The 90/90 is only useful in my opinion if you are going to run Direct Port nitrous. The pre-drilled ports are a very nice thing to have.

curtisad

iTrader: (4)

I wish they had a dyno chart showing the differences between the LS1 intake versus the LS6 intake!! I am ding that swap in April

BADFNZ

iTrader: (19)

https://ls1tech.com/forums/generation-iii-external-engine/455807-intake-comparison-spreadsheet-graphs-inside.html

Louie83

iTrader: (3)

Come to think of it, a few people who have switched from LS6 to 90/90 have said they only gained 1HP and then they re-tuned it after adding the 90/90 and gained another 15-20ish up top. I think the 90/90 is a drastic enough change from the LS6 that it needs a tune.