alternate throttle bodies

[Froggx]

Call me the noob I am if this is stupid, but is there a reason we don't go for alternate throttle bodies on our 3x00's? I notice the LS1 throttle body is way up there at 75 mm, vastly larger than the aftermarket 62mm we seem so fond of. Making an adapter plate doesn't really look that hard to me either, and finding a stock LS1 TB and making an adapter plate would beat the mess out of paying $200 for a 62mm. I'm aware the plenum can't quite be ported out that large, so that would be a disadvantage, but why else do we avoid this?

[StudlyCamaro]

RE: alternate throttle bodies

no need for 75mm

[Froggx]

RE: alternate throttle bodies

I didn't mean necesarily 75 mm, the ls1 TB is just the one that jumped to my mind, what about 65-70mm, maybe on the 3500 manifold since I hear they can fit a 70 mm TB.

[Mars]

I opted for a 70mm, cause I got one cheap on e-bay...





Before Porting :



After :





Again, people will argue that this mod is "dumb" cause that much airflow isn't needed, but we will see soon enough. Price was also right at about 1/3 of the price of a 62mm one.

[XLR8ING]

Very nice Mars!!

[Froggx]

do you know what application and such that throttle body is for? Did the TPS sensor and cables and such bolt up easily enough? An alternate TB that is bigger for 1/3 the price would be great in my book.

[RacerX11]

Looks like a Ford Mustang TB to me...4.6L? I see the 65mm version of these going cheap on Ebay asll the time. Don't forget you need to rig up some sort of IAC. I have a similar 65mm BBK for a Mustang on my 3400 plenum. Definitely a low-buck way to upgrade.

Marty

[Mars]

In deed a Mustang TB... 4.6

The Ford TPS is pretty darn close to what t should be... I did have to enlarge the mounting holes and rotate it on its axis a bit.

Stock 3400 :

Closed : 0.56 V
Full Open : 4.52 V

Ford Part :

Closed 0.64 V
Full Open : 4.52 V

So the span of the ford part is off by 0.08 Volts... but as I said I can twist it on it's axis to acheive whatever I want, but still I am short 0.08.

I think this will not be a big deal.

As for my IAC, well I am going with something remote mount, with a vacuum and filtered air line running to it. UNLESS, someone here can maybe let me know of a better way to do this....

Here is a pic of my progress on that.



:P :P

Should be good to make 3-4 with that chunk, LOL.

[Scott_68B]

Has anyone tried a throttle body from a 3800? Wondering if that might be a viable option at all?

Thanks!

-- Scott

[RacerX11]

As for my IAC, well I am going with something remote mount, with a vacuum and filtered air line running to it. UNLESS, someone here can maybe let me know of a better way to do this....

I am using an earlier style Mustang TB that uses the integral idle valve, so I am just making an adapter block to mount the GM IAC where the Ford idle valve used to be. Your method of remote monting with hoses might be the easiest. Make sure you use large enough ID hose to supply enough air.

Marty

[Mars]

Has anyone tried a throttle body from a 3800? Wondering if that might be a viable option at all?

Thanks!

-- Scott

Ever seen one? Looks like they would not flow too well... It has a wierd bump inside the throttle opening... You can see pics at the ZZP site.

Maybe a 3.4 quad cam one would be better...(the years that the TB was not integrated into the plenum)

[sharkey]

as for the tps on the mustang tb- the stock 3400 tps is meant to be set from .5-.75, so it should work just fine.

[Mars]

as for the tps on the mustang tb- the stock 3400 tps is meant to be set from .5-.75, so it should work just fine.

Hmm, thats what the 3400 one should be set at, well, I am running a 3.1 ECM... so I don't think this will apply. Wouldn't happen to have that spec for the 3.1 would ya? 91 J-body, to be exact.

Sorry about the confusion, heh... but I know for a fact that the ECM saw idle and WOT fine with the 3400 TB mounted on there, my datalogs prove this. Could be the same spec...

[sharkey]

same dea lwith a 3.1l. infact, most gm's are set that way, there is always a range, not an exact setting. .5-1 is usualy considered idle for the most part, and anything over 4.5 is WOT, but at 80% throttle (3.5 volts) he ecm goes into open closed loop, so as far as the ecm knows, you are at wot

[Mars]

I am using an earlier style Mustang TB that uses the integral idle valve, so I am just making an adapter block to mount the GM IAC where the Ford idle valve used to be. Your method of remote monting with hoses might be the easiest. Make sure you use large enough ID hose to supply enough air.

Marty

Hhhhhmmmm. Good idea man, Now I am re-thinking my EGR block off plate, could prolly get a block mounted on that thing... hmmm.