mikesimpalass

Im in the middle of a 370 swap into a gbody monte carlo, and im considering a fast intake. My set up is as follows, thompson 370, tsp 228r cam on a 112, prc stage 1 ls6 heads milled for 11-1, 8.1 marine injectors.

I still have the original lq4 truck intake with a dbw 78 mm throttle body, and i need some advice on whether or not to upgrade to the fast. I have seen poets that claim a 30 horsepower gain, thats pretty significant.

i would have to use an adapter to mount my 3 bolt 78mm tb to the 4 bolt fast flange, or would i need a larger throttle body to see the benefits of the fast? I could buy a 90 mm ls2 dbw throttle body with an x-link as an upgrade. But is it all worth it for me?

As i see it, i have 3 options.
1. Leave my stock intake and throttle body

2. Buy the fast intake and use an adapter to run my old throttle body.

3. Buy a fast, an ls2 90mm dbw tb, and an x link. This is obviuosly the best option, but its also a pretty big pile of money.
Sorry about the lenghty post, im just looking for some advice.

Hardcoresoldier

iTrader: (2)

what is this going in? Odds are the intake will not clear your hood or cowl. The truck intake is HUGE

mikesimpalass

Its going into an 86 monte carlo, the truck intake actually clear the hood on those cars.

mikesimpalass

Thread bump, I think I am going to go with the fast. Am I wasting my time reusing my stock 78mm tb?

thunderstruck507

iTrader: (18)

I wouldn't.

If you want a good throttle body on a budget, look at the Ballistic Speed 92mm. They are a sponsor here and the TB is not widely known, but it should be because it is excellent.

https://ls1tech.com/forums/generatio...ttle-body.html

RezinTexas

I recommend the FAST 92 or 102 for correct fitment on the LSXRT. Also, use a tuner that has had success with the LSXRT previously.

mikesimpalass

I looked and the speed engineering tb is very reasonably priced, but it won't fit the lxrt? My other problem is that my intake is dbw, I've been considering changing it over to cable. The dbw nick Williams Tb is a nice unit, but a little rich for my budget right now.

As an alternative to the fast route, what if I used a tbss intake that already has the dbw 90mm tb?

RezinTexas

I can't comment on the fitment of a TBSS TB to the LSXRT, however here is what the NW 92 TB looks like on the LSXRT.

mikesimpalass

IM also considering the car fast lsx, seems like used fast car Intakes sell for a reasonable price. For the difference in price from a used car fast vs truck fast, I could make my truck accessories work with the car intake.
Sorry everyone, I guess IM at a point where I have several different options and IM not sure which way to go.

CBM Motorsports

iTrader: (2)

We have had some issues tuning with the FAST truck intake. At idle on engines with a large cam, it causes the KPA to jump all around. The intake manifold sucks in and expands (thin plastic). Stock cam engines work fine but the larger cams cause problems. Anyone else had this problem?

RezinTexas

my LSXRT is very rigid and does not flex at all. It was tuned by Patrick G with his custom 224/228 cam and it drives absolutely just as good as when I had the OEM Gen 3 truck manifold installed. Idle is perfect and smooth. Above 4k RPMs it really puts a smile on your face

studderin

iTrader: (28)

go with the bigger TB 102, I wouldnt swap if your gona use the stock