2.0 LSJ Engine: How To Install Big Bore Throttle Body For Cheap!
Id be all over this if i wasnt in the middle of switching jobs right now, even so im thinking about just ordering the plate anyway, throw it on the credit card, I can always get the TB later
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Joined: 11-11-05
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From: Oceanside, Ca
Many people, really the wrong place to be asking this question. Just search a bit and you'll find more.
I found this on a related cobalt site.....figured it could be useful
So, you want a larger throttle body.....
I found this on a related cobalt site.....figured it could be useful
So, you want a larger throttle body.....
Originally Posted by Anonymous Smart Guy
for your wonderful LSJ.
well here is the easy way of doing it.
throttle body spacers are already on the market for some of these. not all of them? not sure why, they all bolt up the same.
airaid makes tb spacers that WILL work for the following throttle bodies, which bolt onto the lsj.
part numbers
200-585
200-586
COLORADO 04-05 Throttle Valve Assm; 3.5L
ENVOY 05 Throttle Valve Assm; 4.2L
TRAILBLAZER 03-05 Throttle Valve Assm; (4.2L)
HUMMER H3 06
BRAVADA 03-04 Throttle Valve Assm; (4.2L)
ENVOY XL 03-05 Throttle Valve Assm; 4.2L
ENVOY 03-04 Throttle Valve Assm; (4.2L)
IMPALA 06 Throttle Valve Assm; 5.3L
ISUZU ASCENDER 03-05 Throttle Valve Assm; 4.2L
GRAND PRIX 05-06 Throttle Valve Assm; 5.3L
ENVOY XUV 04-05 Throttle Valve Assm; 4.2L
TRAILBLAZER EXT 03-06 Throttle Valve Assm; 4.2L
CANYON 04-05 Throttle Valve Assm; 3.5L
MONTE CARLO 06 Throttle Valve Assm; 5.3L
TRAILBLAZER 06 Throttle Valve Assm; 4.2L
RAINIER 04-05 Throttle Valve Assm; 4.2L
SAAB 9-7X 05-06 6 cyl
now that you have the tb and spacer. you also need a 3.5 inch to 2.5 inch coupler. hose techniques has them in stock. it's a rare size, so it's not easy to find.
if this is done right, you can have less then 100 dollars in the mod
well here is the easy way of doing it.
throttle body spacers are already on the market for some of these. not all of them? not sure why, they all bolt up the same.
airaid makes tb spacers that WILL work for the following throttle bodies, which bolt onto the lsj.
part numbers
200-585
200-586
COLORADO 04-05 Throttle Valve Assm; 3.5L
ENVOY 05 Throttle Valve Assm; 4.2L
TRAILBLAZER 03-05 Throttle Valve Assm; (4.2L)
HUMMER H3 06
BRAVADA 03-04 Throttle Valve Assm; (4.2L)
ENVOY XL 03-05 Throttle Valve Assm; 4.2L
ENVOY 03-04 Throttle Valve Assm; (4.2L)
IMPALA 06 Throttle Valve Assm; 5.3L
ISUZU ASCENDER 03-05 Throttle Valve Assm; 4.2L
GRAND PRIX 05-06 Throttle Valve Assm; 5.3L
ENVOY XUV 04-05 Throttle Valve Assm; 4.2L
TRAILBLAZER EXT 03-06 Throttle Valve Assm; 4.2L
CANYON 04-05 Throttle Valve Assm; 3.5L
MONTE CARLO 06 Throttle Valve Assm; 5.3L
TRAILBLAZER 06 Throttle Valve Assm; 4.2L
RAINIER 04-05 Throttle Valve Assm; 4.2L
SAAB 9-7X 05-06 6 cyl
now that you have the tb and spacer. you also need a 3.5 inch to 2.5 inch coupler. hose techniques has them in stock. it's a rare size, so it's not easy to find.
if this is done right, you can have less then 100 dollars in the mod
Senior Member
Joined: 03-20-05
Posts: 6,313
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From: Rutherford, NJ
Hey I just installed mine.....changed my scalar to 4500 BUT the car idles at 1500 rpm when coming to a stop when the car is in neutral...and when I shift, the rpms don't drop fast at all. At idle, the boost gauge reads like 18-20 HG instead of the 24-25 I usually see...Any ideas?
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Joined: 03-22-07
Posts: 24,161
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From: Still fixing others mistakes.
check for leaks. also check and see if the tb blade is hanging up on the blower inlet.
the nature of the ls4 tb is to drop slowly. it did this on my gp gxp. it also did this on my lsj as well.
the nature of the ls4 tb is to drop slowly. it did this on my gp gxp. it also did this on my lsj as well.
Rent me! per hour
Joined: 03-22-07
Posts: 24,161
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From: Still fixing others mistakes.
So what exactly do you have to dremel on the new TB? I didn't really follow that part. This sounds like it might be a nice mod to do.
Anyone?
Anyone?
Last edited by 06_SS_S/C; Jan 16, 2008 at 09:18 PM. Reason: Automerged Doublepost
Senior Member
Joined: 03-20-05
Posts: 6,313
Likes: 1
From: Rutherford, NJ
The supercharger inlet I believe....However, if you want bolt on without the dremel, all you have to do is buy rebels adapter plate which is what I did...You need a way to space the tb out from the supercharger inlet or else the tb blade will hit the supercharger.
Rent me! per hour
Joined: 03-22-07
Posts: 24,161
Likes: 20
From: Still fixing others mistakes.
you don't have to buy rebels adapter. go back one page.
Senior Member
Joined: 03-20-05
Posts: 6,313
Likes: 1
From: Rutherford, NJ
Yeah I know, I was just saying if you didn't wanna do the work (like me lol)...Oh and that problem I was having...it was maf related for some reason...Played with the maf and she idles fine...Still drops the rpms slow though...I don't like that 
maybe I can somehow tune it to drop faster...gotta play around a little
maybe I can somehow tune it to drop faster...gotta play around a little
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Joined: 03-20-05
Posts: 6,313
Likes: 1
From: Rutherford, NJ
Looks stock lol....when you compare the openings though..WOW...big difference...
it was a bitch to tune....then I realized I had an intake leak..I can say, definately gave some good power gains...the gas is slightly more sensitive but definately wroth it. Shyt, probably one of the best mods under 100 bux besides a pulley
it was a bitch to tune....then I realized I had an intake leak..I can say, definately gave some good power gains...the gas is slightly more sensitive but definately wroth it. Shyt, probably one of the best mods under 100 bux besides a pulley
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Joined: 06-11-06
Posts: 536
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From: Chesterfield, MI
I found one for sale from a junk yard but it's listed as "throttle body valve assembly." I emailed to find out of that's the whole TB or just the internals. Only $50 if that's the whole thing though.
However, I also found a few for just $75, so not bad! I'll probably do this when I get a tune for my 2.7" / 60 lbs / dp / ported blower (already done). I've got all the parts (except the TB obviously).. just need the tune!
However, I also found a few for just $75, so not bad! I'll probably do this when I get a tune for my 2.7" / 60 lbs / dp / ported blower (already done). I've got all the parts (except the TB obviously).. just need the tune!
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Joined: 08-13-05
Posts: 5,733
Likes: 1
From: the glove
unless the entire intake runner for the blower is ported you will see vary minimal gains, once again the basics apply.
the smallest point in the system, determines system flow.
this larger TB simply max's out whats available as-is.
also the reason why people are giddy over the quicker revs is due to the larger low-TPS air flow and the faster rate at which the engine hits MAX VE, while at a lower TPS then stock thus making 10% TPS act like 30% did on the stock TB (for example only)
the smallest point in the system, determines system flow.
this larger TB simply max's out whats available as-is.
also the reason why people are giddy over the quicker revs is due to the larger low-TPS air flow and the faster rate at which the engine hits MAX VE, while at a lower TPS then stock thus making 10% TPS act like 30% did on the stock TB (for example only)