NA8C Throttle Body

[project.r.racing]

Who as modified their NA8C throttle body?

Can it be enlarged?

Can bigger aftermarket ones be brought from somewhere?

Please help.

Ryan

[93_Clubman]

hamish71 modified his nb8b tb - see following thread:

viewtopic.php?f=44&t=33855

Probably need to buy from the US to get a larger aftermarket tb, or enlarge via the aforementioned thread locally.

[project.r.racing]

Thanks.

I had spoken to my mechanic months ago about it, he looked at it and said that about 1.5-2.0mm could be taken off and a bigger butterfly be put in. He said around $300 at the time.

Interesting to hear that is reduces throttle response and increases high end power. Unless the high end power is a big gain? I'd probably just keep the tb the way it is. I'd prefer throttle response over a 2-3kW gain.

Any one know the gains he got in the aforementioned thread?

Ryan

[Fuzzlet]

Rather than fitting a larger throttle body, how about looking at free-flowing your current one?

[project.r.racing]

Rather than fitting a larger throttle body, how about looking at free-flowing your current one?

Please explain?

[93_Clubman]

Interesting to hear that it reduces throttle response and increases high end power. Unless the high end power is a big gain? I'd probably just keep the tb the way it is. I'd prefer throttle response over a 2-3kW gain.

Any one know the gains he got in the aforementioned thread?

I believe hamish71 didn't complete the project before selling the vehicle & parts (mostly) separately, so not sure if he got to measure any gains from the mods he had completed.

I think if you read the thread again, hamish was indicating that the new owner opted to purchase the OBTB as he found it provided better throttle response, hence hamish longer had the OBTB when I enquired, just the NB8B intake manifold & a stock TB which he could get modified for me.

I think Fuzzlet means bore out your stock TB rather than buying a OBTB.

[Fuzzlet]

I havent had a detailed look at the TB on my SE, however on a previous car (95 model V6 magna), the inside of the throttle was rather rough, and the stop ring for the butterfly stuck out 2mm. Obviously designed for quick + cheap, not performance (remember it is a magna). I attacked it with a small grinding stone and shaved the ring down to approx 1mm (no problems with throttle not shutting properly etc), and polished the insides. Didnt givemuch of a benefit power wise (lazy 3L V6), however throttle response was slightly improved