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LSJ TB on a 2.4

6K views 11 replies 9 participants last post by  King-Oka 
#1 · (Edited)
Hey everyone, new to the forums but a long time lurker! I am the proud owner of an '07 N/A Solstice, which I have been buying and installing mods for myself over last two years I've owned the car (K&N CAI, Solo headers, Magnaflow cat-back, Venom/Backbone braces).

Anyways, I just bought and flashed a Trifecta canned tune, and told them that I had a big-bore throttle body installed (I don't YET, but installed the tune on my car anyways and it is working fine so far). Reason is, I have been eyeing the LSJ throttle body; just looking to grab a few extra HP, but really looking for increased throttle response. I wanted to make sure I have the right part to make it fit: LE5 Throttle body Adapter Plate . That is all I need right, no extra cables or anything?

Thank you for your help guys (and gals),
Frank
 
#2 · (Edited)
Hey, so I just wanted to give everyone an update. I went ahead and bought an LSJ throttle body used on eBay with around 50k miles on it for $65, and the ZZ-LE5TBAP-88 adapter plate+wiring harness from ZZPerformance. I had a problem with ZZPerformance not sending me the bolts for the adapter plate, but I contacted their customer service and they sent me some. I still had to go to home depot and buy 4 more longer bolts to secure the throttle body to the adapter plate, which I have no idea why they don't include when they know the adapter plate is being used for this application, but it was a minor setback. Installation was super easy, and the wiring harness worked perfectly. Trifecta re-did my tune, and everything is working great!

Do I notice a difference? Yeah, at WOT, the car does seem to move a little faster, and I don't think it's placebo. So far I don't notice increased throttle response or anything else. Do I think it was worth the $200 I spent? Probably not, but hell, this is my little project car I have been learning to install stuff on, and it's been a blast. So I am not disappointed!

Just posting about my experience in case anyone else wants to proceed with this upgrade!
 
#4 ·
Do you have evidence that the stock TB is a power limiting factor?
 
#5 · (Edited)
I looked into this set up a few years ago before the turbo install and the bottom line from a couple of people that I talked to was the increase in horsepower was marginal at best so I passed . Just to add I had pretty much the same engine set up header ,CAI, Magnaflow exhaust and a tune by a local performance tuner .
 
#6 ·
I looked into this set up a few years ago before the turbo install and the bottom line from a couple of people that I talked to was the increase in horsepower was marginal at best so I passed . .
Yeah - that's what I thought.
Like people believing that if theoretical flow is greater it must make more power - good example is GXP air intake. Fact is that if it already flows more than enough there is no gain.
 
#8 ·
DDM Offers the bigger throttle body as part of their stage 3 supercharger kit. With it, obviously, the piping size increases from it intake through to supercharger intake, where then it restricts due to the size of the Magnusson. They have HP performance numbers documented for stage three, which also includes headers, bigger injectors, and a more agressive tune.
 
#10 ·
IIRC the area of the LE5 throttle body is smaller than the inlet of the intake manifold and the LSJ TB is quite a bit larger. This swap should have gains provided the pressure differential before and after the throttle body is closer to 0. If swapping throttle bodies in an NA application, if the manifold absolute pressure is closer to the barometric pressure, then gains will likely be observed. I've not tested it, but I think you are right that you are making more power.

Also with drive by wire, the throttle response is 100% tune-able without swapping parts. I know you said you have trifecta tune, but hp tuners has a table for throttle % vs pedal % in the E67 pcm that you can calibrate to your liking. I assume trifecta can do the same if requested.
 
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