Lexybird

has anyone ran this on a c5 yet ? And if so what is your opinion . Looking for reviews of those who actually run this intake . It looks like after porting out the horrendous casting flaws on the intake runners this thing could eclipse the tried and true ls6 manifold . I know about the all cylinders test was close to the ls6 but I've yet to see anybody test it on an average application closer to 350 horses instead of a 550 horsepower beast test or test it after it's ported correctly . Anybody ?

DetroitPlac

I'd go for the new LS2 (which is basically the LS6 with a 90mm TB snout) for the same price if changing.

Lexybird

Well I just plan to keep it mild with bolt ons so I'd rather not lose the velocity by running a bigger intake than my heads can flow . I was thinking a ported dorman ls6 and vmax throttle body headers caI and a tune

Gordy M

Just pick up any 01-04 Intake and then bypass all the casting flaws. Mild porting job and your done. You would be better off getting a good tune done by COW after your changes and wake up the engine throughout the RPM range.

zdeckich

LS6 intake is much better than a LS2 intake stock for stock.

'Shifter

Huh....bringing one over from my warehouse as we speak....

'Shifter

Got it in and looked it over, it's actually Made In the U.S.A.!

Anyway, yeah, the ports are pretty rough....even with an employee discount it was still pretty expensive, but way cheaper than a F.A.S.T. unit.

I wouldn't mind seeing a flow comparison with an OE unit though.

Lexybird

dorman uses a fast 78 version lower shell for this manifold . Lots of potential . Guys on ls1tech have tutorials on porting them . The snout is only 73 mm so that needs opened up as well to match your throttle body . The wedges need ground out of the intake windows . Summit racing sells these for a little over 300$ .. tgatvsure beats 900$ for a fast intake or 450$ for a used ls6 manifold that is twenty years old with the possibility of hidden stress fractures .

Lexybird

I pulled the trigger and bought one from summit for 322$ shipped . It looks very high quality and much better than an ls1 intake . Will able to flatten down my coolant lines on this or am I forced to get the ls6 crossover kit . Anybody running this know ???

momo20

why would you want to do that..the ls6 outflows the ls2 and is less prone to leaking due to how the ls2 intake was sonic welded ...

Lexybird

I went ahead and bought this intake . I smoothed out transitions and radiused all inner edges .i ported the flaws and wedges in runners and opened up the throttle body opening to 76 mm . Looks far superior to the ls1 intake ( much more volume.). I will be installing in the next week or two and will give my Sotp impression after.

cv67

plenty more on the table with that intake, youre off to a good start

Used LS6 and Fast prices are

Couple hundred for a new one and some time witha grinder more bang/buck

Lexybird

That's what I thought , I'm not blowing 500 bucks on some twenty year old used ls6 that's questionable when I can get nearly the same thing new but with a much improved patented fast racing 78 lower shell . These guys wanting gold for their ls6 intakes are getting ridiculous lately. Who knows if it was boosted internally cracked or dropped off a bench over that time

v8srfun

Some of those thermal reducing intake gaskets should space the manifold up enough to not need to mod the steam pipes

zeevette

So you're limited to a 3 bolt TB with the Dorman? Don't see much of a gain without using a LS2> 4 bolt.

'Shifter

Looks good man!

Lexybird

The bigger 90 mm + is not really needed until you do cam and head .a lot of gains I've seen on dyno runs appear to only show the bigger throttle body being a benefit after 5,000 rpm and it's like 5 hp a lot of time . For a mild 5.7 street car you'll likely never see the benefit over a factory 75 mm TB

zeevette

Then, why bother? When I added a ported FAST90 to my H/C car, it added 27 RWHP with a slight retune.

Lexybird

Ok Then your race head and cammed car obviously needed the extra flow on your particular car . But as I stated For a mild 346 street car with an ls1 crappy I take this would be a big upgrade was my point

zeevette

I only ran a 228-232@112/.600 Crane cam; not large at all. I don't know about "race" heads; they were the best I could afford, but intended for street only, as I do not race.