Gradient

Looking for some insight. They are the same size 78mm, but would a ported FAST 78 be that much better than a ported LS6 intake?

vettenuts

Correctly ported, the FAST 78 will outperform the LS6.

ZZ06

Are you finding one for cheap? I havent researched this but i figure the amount it would cost you may want to up the size

Gradient

I am finding it difficult to get a hold of a FAST 90/92, but I have come across a 78.

1stGlance

http://forums.corvetteforum.com/c5-p...ttle-body.html

Gradient

Yes, but I am looking for a FAST manifold. I have an LS6 TB/intake.

Gradient

My question was worded incorrectly. I am debating two options:
1. pay to get my LS6 intake ported
2. purchase a ported FAST 78.

Option 2 is more $$$ and I am wondering if the gains are that substantial to warrant the extra $$$.

099blancoss

port the Ls6 and call it a day.. if you were going FAST 102 then Ok but you also have to look at the application.. do you need more air up top?

98vettedave

A properly ported 78mm FAST will only be approximately 5 hp less than a stock 90mm FAST,this as stated by Mr. Mamo back in the day. I run a ported 78mm FAST and my 383 dynoed at 482/442 rwhp n/a at Livernois Motorsports. If you can pickup the 78mm FAST for a "good price" and then have it ported...it will support more hp than most realize.

chevy406

I put down 471 rwhp with my self-ported FAST 78. I don't have any way to compare it to a ported LS6 manifold though. If you sell your LS6 manifold for ~$300 and buy the FAST 78, how much money will you be out? You should be able to get the FAST 78 for under $500. I bought mine for $400 already painted, and then I did some port work at home.



If you do end up buying the FAST 78, make sure the sharp edge behind the throttle body is rounded off. Mine had an annoying whistle at throttle tip-in, and Tony Mamo clued me in to rounding off that edge (upper right corner behind the throttle body)


after rounding the edge:

099blancoss

Mamo does great work no doubt... but I dont think he ever ported an LS6 intake and compared them side did he?

Gradient

I found a 78mm for $600 and it is not ported. That seems a bit high to me. I am leaning towards porting the LS6 because it seems like more bang for the buck. I don't plan on using any forced induction on my car.

Thanks for all your replies and pics!! Great information.

98vettedave

The LS6 is a good intake for the price,but from what I understand there is very little to be gained by porting one...don't waste your time or money!

chevy406

I agree that $600 is too much for a FAST 78mm intake. You can buy a brand new 92mm or 102mm for $830 and there are always some used 90mm intakes on forums in the $600 range. Of course you would have to buy a larger throttle body if you went with the bigger intakes. From what I understand, the bigger openings will increase throttle response, but I'm not sure if it's worth the money for either your or my cases.

sami85L98

JJ formato another great porterr, said the same thing, dont bother porting LS6, he never gained any HP. However 78 FAST is upgrade from LS6 in HP Dept not in quality though.

I would wait and go staright to 102 FAST/Ls2 TB.

099blancoss

I dont about that, I havent used or ported an LS6 BUT there used to be a lot of guys claiming good gains with them.. just as good as a non ported 90...

I will say this: the price of the them is stupid !!
You cant find an LS6 for under 300 shipped.. I have a project I am working on and doing a conversion and looked all over for a cheap LS6... none to be found had to go with a Vic Jr

But you also have to look at application... does he have a cam? why does he need more air up top?

Gradient

So now I have a real dilemma- one person says no gains for porting the LS6 and another just the opposite.

I plan on putting in a mild cam, LG long tube headers so I might need a little more air up top. The 102 is def way too big for my application, so I am not even considering it. I don't want forced induction or a heavy cam.

I think the decision has been made to go with a ported FAST 78. Thanks all the good info guys.

Just an FYI- I have a BBK CAI and it is no good. I would not recommend it. I did not get it tuned, but my gas mileage actually dropped 2 mpg and I don't feel any difference in the throttle response.

98vettedave

Guy's claiming good gains with ported LS6 intakes...comparable to a stock FAST 90... Why don't you ask Mamo or Formato about that!

98vettedave

I agree that the FAST 102 is superior in quality to all prior FAST intakes.

099blancoss

Actually Tony and I have talked quite a bit.. there were some good gains with porting the LS6 and yes it was comparable to the point that unless you ported the 90 its wasnt worth the money to buy a 90 but that was a while ago.,. the 90's havent been out for a long long time and Mamo and Formato aren't the only people who port intakes or post results.

I'm not going to banter about it theres no value to it at all.. you believe what you want and we'll call it good


The 102 is best of the best no doubt

It all comes down to application.. cubic inches rpms and need for air