Dorman ls6
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From: Atlantic Pa
Dorman ls6
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 ?
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From: Atlantic Pa
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
Melting Slicks
Joined: Feb 2001
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From: Northville, MI
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.
Last edited by Gordy M; May 23, 2017 at 09:29 AM.
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16-'17
NCM Member '09
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.
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.
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From: Atlantic Pa
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.
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.
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 .
Last edited by Lexybird; May 24, 2017 at 03:17 PM.
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From: Atlantic Pa
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 ???
Safety Car
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From: pueblo co
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From: Atlantic Pa
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.
Last edited by Lexybird; Jul 23, 2017 at 11:12 AM.
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From: altered state
St. Jude Donor '05
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
Used LS6 and Fast prices are
Couple hundred for a new one and some time witha grinder more bang/buck
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From: Atlantic Pa
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
Last edited by Lexybird; Jul 23, 2017 at 07:57 PM.
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From: Atlantic Pa
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
Race Director
Joined: Sep 2005
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From: Pasco WA
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
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From: Atlantic Pa
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
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From: Pasco WA
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.