CardinalsRed

what size is our ls4 throttle body? i was lookin at the vararam velocity stack and the vararam throttle body spacer. just wanted to make sure they would fit.

http://www.vararam.com/vr3.html

http://www.vararam.com/tbs1.html

Mgpeagle

iTrader: (6)

I think out TB's have a 3 bolt holes, not 4. I think someone on here used an Air Raid TB spacer and it fit but I believe it had 3 bolt holes. May want to try a search. Not sure about that velocity stack thing. It kind of looks flimsy.

-Mike

Area47

do a search for ls4 tb

scarlett

Do a search but the Air Raid fits perfect; It is from a Sonoma matches up all 4 holes also.

MonteSS8707

iTrader: (4)

The TBS won't fit. Its too big. The TBS you need is AiRaid 200-586. Its for chevy trailblazer/gmc envoy with the 4.2L inline 6. Our throttle bodys are the exact same as those. I doubt the vararam velocity stack will fit either. It'll be too big also. Our TB is like 76-78mm dia. The other LS engines are about 85mm dia factory. Hope this helps.

CardinalsRed

it does. thanks. i thought the basic set up of the ls4 is close to that of the ls2 but i guess things like the throttle body are different

Taz34SS

iTrader: (2)

Way different. If you had done a SEARCH, you would have found that out.

CardinalsRed

you say our throttle body is 78mm? would the 78mm FAST intake manifold work for these cars?

Taz34SS

iTrader: (2)

DO A SEARCH... I have no idea how many posts there have been about the any of the Fast intakes.

dcrews

iTrader: (3)

Back on topic.. Does anyone have any concrete info on weather the throttle body spacers work and how much power/mileage gains they actually provide?

Taz34SS

iTrader: (2)

I am not sure of the weather in your part, but the weather here is great.

On the TBS, they are ok, but honestly, I would not spend the money on them unless you were running a car that was Supercharged, then its worth it.

dcrews

iTrader: (3)

LOL I didn't even notice I screwed up the 'weather'!

Does anyone do ported throttle bodies for our cars? And do they have the gains that ppl see on the LS1 cars? I know on my TA, I could feel a noticeable difference when I went from stock to a ported TB..

MonteSS8707

iTrader: (4)

I have no concrete dyno evidence on the TBS. But I think it seems to help passing power slightly. Also if paired with a CAI it gives you a whistling/swooshing sound. Kinda like a supercharger. A guy from scoggin dickey gmpp told me you might see a .5 -2 hp gain on our engines. Not really cost effective i guess but I like the results. Your best bet is to go with 1.8 ratio roller rockers and an HP Tuner tune. It'll make a night and day difference. Trust me.

CardinalsRed

a friend told me there were making a f.a.s.t intake manifold for our ls4, has anybody heard of that too?

Taz34SS

iTrader: (2)

I hate tell ya this, but unless something changed within the last 48 hours, they are still not making an LS4 intake.

CardinalsRed

dang that sucks