What size Throttle body

[stevesLX]

I have a 89 LX stock 302 w/ the exception of a edelbrock manifold and edelbrock 5.0 performer plenum, 24# injectors. The TB on there right now is a BBK 75mm and it also has a spacer on there doesn't appear to be factory but anyways I have been told that that TB is to big for the setup I have and that I loosing a lot of low-mid range power because of it. I know where I can get another TB its used on a 87 GT at a junk yard but I think it is stock. What size are the stock ones and what size do you guys think I should use?

 

[SVT32VDOHC]

I would keep the 75MM. It may be a little too big for now, but you will do more mods later I'm sure. This is a discussion that could go on for a while on this site.

The stock T-body is 60mm.

I would also upgrade your Mass Air Meter, to help the 75MM T-body. The stoc Mass Air is only like 55MM or 58MM. I would upgrade that instead of buying the stock T-body...Don't go backwards.

 

[stevesLX]

The MAF is 65CFM

 

[gcwh02]

what brand is it, ill trade you my bbk70mm for your 75

 

[stevesLX]

Its a BBK 75 mm

 

[gcwh02]

Its a BBK 75 mm

its up to you, but I am willing to trade as my combo is in need of a 75mm

 

[Grn92LX]

The 75mm is fine. But you will need to port match the edelbrock upper inlet with a dremel to match 75mm as its only 70mm out of the box.

Keep the 75mm, you'd be silly to get rid of it!

 

[5spd GT]

Even though you really do not need that throttle body until you start pushing something with boost, I would keep it, unless you find an even trade for something a tick smaller

An n/a engine (stroked or not) is not going to flow near enough cfm to even warrant needing a 75mm (700+cfm) throttle body. Just a FYI.

Yeah, port match the inlet opening on the intake so you don't get turbulence.

 

[stevesLX]

I really dont want to go messing with my intake I can get this other TB for 20.00. With the injector size I have(24#) and a C&L 65 CFM is that going to affect anything with this other TB. I beleive its a stock TB. With what I have right now you can hear the hissing or wined of the air and it seems like it is real sluggish here and there from time to time. Also everytime I take my intake off I have water or moisture that wants to come out. I do have a 4 inch cal induction hood on this and I know water gets into the engine compartment when I wash it but is this normal to have water comeing out of here. The air intake is just the factory rubber tube from the TB to the MAF and then theres a K&n air filter hooked up to the other side of the MAF housing. And the vacum line that goes from the vacum housing on the firewall to the intake always has oil in it when I pull it off. Whats the deal with that. The oil I seen in it last night was fresh oil. I have no clamp on this hose it just slides onto the elbow coming off the back of the intake.

 

[BK_CAULEY]

PCV

my guess is it has something to do with your pcv valve.

 

[Cwalk]

If you absolutely have to get another throttle body(which I wouldn't). I would go with a 65mm throttle body. You can get one pretty cheap.