Changing Throttle bodies

[DMG_90_No.18]

I changed from the standard VN V6 throttle body of 60mm to a 70mm throttle body, but the Engine Warning Lamp stays on. The car runs well. I removed the ENG COMP fuse and the Warning Lamp went off for 2 seconds and came back on when the car was started. Only thing is at the end of the butterfly shaft where the Throttle Position sensor goes it is of a different size from the standard (smaller) could this be a problem. Please Help.

[Morton]

That could be it... change back to the standard throttle body and see if that fixes it. If so, then you know the problem is in the new TB. If it doesn't fix it, then you know something's broken

70mm throttle body won't change anything on the car anyway, so there's no harm in putting the 60mm back on and keeping it that way

[savage1987]

Are there any benefits to changing TB size in a stocko six? If greenfoam reads here I'd love to know a bit about the relationship between TB sizes and retuning possibilities..

[Morton]

No benefits at all. The throttle elbow between the throttle body and the inlet manifold is less than 70mm in diameter.

[Cheap6]

Agreed, no benefits to maximum power (the T'body isn't a major restriction at near standard power levels). It will change the relationship between airflow and pedal position so it will feel better (at part throttle positions).

The check engine light is probably due to a throttle position sensor fault code, because the TPS is not being rotated by the smaller end of the throttle shaft. There should be a small adaptor that fits on the end of the throttle shaft to drive the TPS. I'm not sure if you can buy that separately though.

[Zuicider]

i noticed a big difference when i chucked a yella terra 70mm on but even more difference when i go the die grinder onto the elbow

[greenfoam]

On the V6 there is more than enough in the standard throttle body, the throttle body flows something like 500cfm, you would need a really mean V6 to get anywhere near needing that much air. Everyone thinks they are going faster because with a 70mm you get to 1/2 throttle at 1/4 throttle but all you are doing is the same thing as pushing twice as far on the accelerator as you were before

[savage1987]

Knew that Jason I'm not retarded

Was just wondering, my VN is quite sluggy (VTish) after my uber-lean tune, so thought maybe a bigger TB would wake her up a bit