Rise of the Phoenix

iTrader: (27)

I've got a chance to purchase a used FAST 90mm intake and I think I'm going to jump on it. I had intended to do a FAST 102mm setup, but this intake already has the Nitrous Outlet Money Maker system plumbed, which is something I was going to eventually do to whatever FAST intake I purchased. My question is this; would a ported/port matched FAST 90mm intake be on par or better than a FAST 92mm intake? I would port out the inlet to 92mm and port match the runners to my heads. My current setup makes 447 rwhp and 431 rwtq. Any ideas on how much I'd gain with a ported FAST 90mm intake?

SoFla01SSLookinstok

I think the only difference from a FAST 78 to the 92 is the TB opening. I'll guess you gain 21hp. How is your induction set up? I see the SLP lid.

Rise of the Phoenix

iTrader: (27)

Stock LS6 intake with a bone stock/unported TB. I removed the MAF, as I'm SD tuned, so I have a smooth hose that goes from the TB to the Lid.

I'd be happy with 21. Porting the opening of the intake shouldn't be hard at all, and not much material would need to be removed to get it to 92mm.

kinglt-1

iTrader: (26)

I seen that intake for sale and instantly thought of you...

blk00ss

iTrader: (66)

IIRC, back when the fast 92 came out, it wasn't for making more power. Just cleaning up some stuff with it. Like threaded inserts in places where the 90 used nuts and bolts. I believe there was several dyno test done as well. I don't believe the 92 ever made anymore than the 90.

Rise of the Phoenix

iTrader: (27)

Well, I didn't act quick enough; it sold. I should have bought it yesterday, but oh well.

I guess I'll keep an eye out for a used FAST 90mm intake. They go for quite a bit less than the 92mm and 102mm intakes, and if I can port it myself, it should be better than a stock 92mm intake.

Rise of the Phoenix

iTrader: (27)

That's good to know. The only thing about the FAST 90mm that's scaring me is me porting it. I want to open up the front part of the manifold to 92mm to match the 92mm TB, but I also want to remove some material from the runners. If there is a way I can make myself a template of my heads, I'd also like to port match the intake runners to the heads. Someone suggested taking some thicker cardboard and placing it over the intake ports of the heads and gently beat on the cardboard so that it makes an indentation around the ports. In theory, I believe this will work.

01ssreda4

iTrader: (96)

I placed the bottom shell of my 102 on my heads and it lined up perfectly, no port matching required. Id say do that first before you assume it needs anything.

Rise of the Phoenix

iTrader: (27)

Oh yeah, I'll most certainly do that before touching the intake. In your opinion, do you think a ported FAST 90mm intake will yield me some decent gains over the LS6 intake/stock TB? From what I've been reading, there really isn't much, if any, difference from a performance standpoint between the 92mm and 90mm intake. I'm pretty sure the only difference is the inlet size, as the runners are exactly the same between the two. Please educate me if I'm wrong.

Bill00Formula

iTrader: (4)

I have a 90mm Fast and throttle body if your interested.

big hammer

Fast 92 is a really nice intake for a 346 and makes good power. Easy to install too

01ssreda4

iTrader: (96)

Yes, on the top end.

Rise of the Phoenix

iTrader: (27)

I purchased a FAST 90mm intake today from a member on here. What should I use to port the inlet out to match up with the 92mm TB? Dremel with stone bits?

Chris25

iTrader: (1)

I used regular cartridge rolls. The material is super soft the stone will cut fast. I would also port the runners as well before you install if it hasn't been done, you do not need to take allot of material out just smooth out the runners so they transition better.

Rise of the Phoenix

iTrader: (27)

Are the cartridge rolls sandpaper? I will smooth out the runners as well. I'm going to see how the runners line up with the heads, and port-match if needed.

Chris25

iTrader: (1)

Yes they are Sandpaper, buy the long rolls so you can keep the walls even between the two pieces. You can get them relatively cheap on Amazon with the shanks. The biggest thing with the runners is removing that damn wedge they put in there. Make sure to wear a mask or respirator that plastic is something else.

Chris25

iTrader: (1)

I used this guys write up as a guide when I did mine.

https://ls1tech.com/forums/generatio...90-intake.html

Rise of the Phoenix

iTrader: (27)

I read over that thread last week. I think if I take my time, I should be fine. What would be the best way to get the intake inlet to match the TB inlet? Should I bolt up the TB to the intake and port the intake inlet? I'm afraid if I do that, I may end up messing up the TB.

Chris25

iTrader: (1)

Honestly I just used dykem steel blue layout fluid on the face of the intake bolted the TB up opened it and used a scribe tool to layout what needed to be cut. Just take your time and be patient.

thunderstruck507

iTrader: (18)

Fast 92 was just a revision on the 90mm version. No power difference.

Sanding rolls on a dremel make quick work of the porting. The plastic is strange and kinda just comes off in fibers rather than melting or anything.

You have a pretty healthy setup. I would expect 25hp+ gains over a ls6 with a non-ported tb to be realistic.