To fit onto an EL GLi V8. At the moment I've got factory extractors (ex chaser) and just the standard 2.5inch exhaust and am hoping to get a bit more grunt out of it. Will the 65mm throttle body make much of a difference over the standard one (approx 58mm?) I don't think that its got the explorer intake but still don't know how to tell the difference. Its a June 1998.

Just wondering if I'll need a bigger air intake pipe and if the standard inlet manifold that the throttle body fits onto is larger than 58mm or the same size, because obviously its not going to make any difference if its the same diameter as the standard throttle body.

At the moment it seems to get quite good fuel economy, about 550km from 62L regular unleaded. - I wouldn't think changing the throttle body would change this figure too much either way. I guess its the usual story, more air going in will mean it'll use more fuel when driving hard, and probably less when driving on the freeway etc.

anyone that could offer any help would be great to hear from you!

The upgrade in throttle body wont make a noticeable difference but I guess it is a good starting point if your plan to do further mods in the future.

June 1998 EL XRs got the explorer but i'm not sure about the GLi's.

The throttle body fits straight on too, might be just a slightly tighter squeeze with the intake pipe but you will get it on easily.

I had the standard throttle body ported to 65mm. Not a big difference i must say over standard, but i dont have the best intake manifold so theres an opportunity there. Also its not running any coolant through it anymore. dont know if it results in more or less heat though.


I have a spare one at home if you need. Cheap.

Have you measured the opening in the HO upper intake manifold?

Might be worth having a bit of meat removed from the opening if its not much bigger than the standard TB...

make sure the passage through to the plenum area is at least the same cross sectional area as the TB. other wise it's pointless.

measure up and do some basic area of a circle and area of a rectangle.
some minor porting my be needed

Thanks for the help guys. Sounds like its not going to make a huge difference unless a few other mods are done, but at least its a starting point! I haven't had a chance to measure the opening in the HO upper intake manifold yet - does anyone know if this opening varies in size on the standard manifold and the explorer? Also is the throttle body on the engines with the explorer manifold the same as standard or slightly bigger? cheers!

AU's fitted with Explorer intakes were fitted with a 65mm TB. Putting a 65mm TB onto the stock HO intake will not increase performance as the intake and heads become the next bottleneck.
You need to increase the airflow all the way from the air intake to the exhaust to get an increase.