Ragtop 99

iTrader: (7)

After seeing another post (Max's Dad) about the 90mmm FAST TB, it is time to look at the TPIS unit.

What are the differences?

Any performance or installation reasons to favor one unit over the other?

LawmanSS

iTrader: (19)

The only difference I'm aware of(besides the quality control issues) between the two is that the TPIS unit doesn't have a provision for the fresh air line that runs to the passenger side valve cover...there are ways around this...here's a good thread on the TPIS:

https://ls1tech.com/forums/showthrea...highlight=tpis

WILWAXU

iTrader: (6)

Joel,
Brian (Fireball) has had both to compare. Might help to give him a ring.

NLang

iTrader: (12)

There shouldn't be any performance differences, but fitment could be another story.

beardWS6

iTrader: (1)

My fast 90mm is giving me major problems. Think I`m going with a TPIS.

Fireball

iTrader: (21)

I didn't have both TBs...only the TPIS. FAST wasn't shipping them yet...and I had an intake laying around and got antsy

Squintz Palladoris

iTrader: (1)

I did use both TBs. I got tired of the problems with the FAST an sent it back for a TPIS. Much better quality.

Brad

GrannySShifting

iTrader: (10)

FAST is not very good quality at all compared to the other TB out there. I still dont knwo why people sell them to customers For $20-$40 more (you already spent a grand so why not?) get somethign that you dont have to worrry about the blade slipping sticking open etc etc. Ask Jason what happens when a TB blade sticks open a little bit when its 90-100mm A C5R corvette almost sideswipes a pole INthe shop.

If you have to take it apart to rebuild it before you ever put it on the car, not fancy

JS

iTrader: (4)

The blade sticks because its moving.
Nothing more than a few tweeks and the fast works fine.

Geez,u guys make a big deal about alittle modding.
U peen the shaft like GM does and u reset the screw in the shaft 1/2 way threw and then loctite it,DONE no more problems.

But for 500 I do agree it shouldve been done from the get go.

Damage Inc.

iTrader: (7)

So do you guys just run a hose to the bellow for the PCV with the TPIS throttle body? I'm not sure how I can do this right. I've searched and it seems like everyone does it a little differently.

Squintz Palladoris

iTrader: (1)

I don't run a PCV.

If you are still running a PCV then you can take the hose off and put a small clamp on breather in its place on the valve cover. That hose does not go to the vacuum side of the TB it goes to the front. It allows fresh air to be pulled into the crankcasewhile the PCV is pulling vacuum from the valve covers.

Brad

bmfcamaro

iTrader: (1)

Talked to kris at sdpc and he thought that if you are running an LS2 intake, that it has the provision. if you look at one from the front the left side has a nipple that the other intakes dont seem to have. we believe that the pcv goes right into there. hope that is positive. i will tell you for sure when i do mine. i hope that stops people for settling with the FAST instead of buying what they want.

Squintz Palladoris

iTrader: (1)

That nipple is for the actual PCV and it pulls vacuum.
FWIW if you are running an LS2 Intake the TB is spaced back further and not designed for the throttle linkage to be there. With the FAST TB the throttle cam will Hit that Nipple. I had to trim mine down a bit.

Brad

Damage Inc.

iTrader: (7)

I'm a little confused here. So the passenger side valve cover hose that normally goes to the top of the TB just gets a small breather on it? Isn't this supposed to be a vacuum effect in the TB and not open to normal air?

Fireball

iTrader: (21)

its a fresh air return for the PCV system. It is designed to pull metered air from the incoming airstream.

Squintz Palladoris

iTrader: (1)

There is no vacuum on that port.
The PCV goes into the port in the intake that is behind the TB where there is Vacuum

Brad

Squintz Palladoris

iTrader: (1)

Its like shotgunnin a beer lol. That hose is the hole in the beer can. When the PCV pulls vacuum on the crankcase fresh air is pulled through that hose into the valvecover from the Vacuum created by the PCV system.

I kill Me

Brad

Squintz Palladoris

iTrader: (1)

I tried all of that with mine JS. It was pretty well effed up. The blade was scrubbing in the bore. I managed to stop it from hanging open but it would not come to rest at the same spot when It closed. Sometimes it would get stuck shut. Some are worse than others.

Brad

beardWS6

iTrader: (1)

TPIS here I come!! I will let everyone know Wensday how mine does.

Squintz Palladoris

iTrader: (1)

You Will loose 25hp but only you.





J/K man you will like it.
BTW My LSX 90intake will be here tomorrow Eff this LS2

Brad