Throttle body upgrade

[dss123]

Hi Guys,

Thinking of upgrading the plastic throttle body on my S1 111s.

I have a sports exaust, cat bypass and induction kit already.

The current body is not causing me any problems (yet!) but I was wondering if the sport 160 body would be a worthwhile upgrade - (throttle response etc).

Also, is it a simple swap job or do I need to do anything else.

Your thoughts much appreciated


DSS

[StuartB]

I am just about to replace my plastic one with a 2nd hand 48mm version. Got it from mgfcentre.com (might be .co.uk) only £30 (+VAT + P&P)

Undo the clip holding the air filter pipe, four bolts, unhook accelerator cable, two screws holding seonsor on the far side (as you look from the boot) replace with new one and jobs a goodun - It is meant to take 10-15 minutes so I am putting aside an hour for it

[black_potato]

Easy job....
Improved throttle response and worth while if you are going to tune your car. There is however a chance of runing lean at constant open throttle though.... like with any tuning you always run a risk....

You also need to reset your throttle position sensor, somthing like.. switch the ignition to the 2nd position depress the loud peddle 5 times, switch of the ignition and then start the car as normal.

Also check your cable tension while your at it.

Plenty of discussion in the SELOC archives if you need it.

[timh]

Is the sport 160 throttle body different to the 48mm mgf one that stuart b bought?
does the ECU sort out the different fuelling through what I presume is a larger body for you, or is there some trickry that needs to be done ?

I get the usual sticky trottle occasionally.

[black_potato]

The 160 TB is a 52mm TB... the difference between 48 and 52mm is quite significant... feel free to do the math.

The standard ECU isnt smart enough to make use of the extra air, its not completely stupid... i.e. the Lambda readings measure the results of the fuel air mix and will adjust things to some degree but at high rev's with the throttle wide open you will have the potential of a fuel burn with more air than fuel.. hence the concept running lean.

This said most cars are fueled a little rich so you should get away with it, but there is some risk.

Longer term if your looking for more power its a usefull start but only 1 part of the puzzle.

If your not going to tune it further and your just resolving a sticky throttle an Ali 48mm TB is the cheapest and lowest risk option.

>> Edited by black_potato on Thursday 21st October 19:07

[340ragtop]

Firstly, it's not a sport 160 TB. Done to death over the years, so let's not re-invent the wheel.

It's a trophy 160 TB (ie off the MGF trophy cars). The only car to have the 52mm ally as standard is the S2 111s.

There really is very little power gain to be had with a 52mm TB even if you "do the math". The biggest difference (and one which many don;t like) is that the 52mm TB has a flat butterfly with no smoothing wedge. As a result, the initital opening is more sudden, giving a snappy response.

www.british-cars.co.uk/cgi-bin/gen5?runprog=lotusbbs&mode=archiveth&subject=2050&subjectar=2050&thread=200203081259161122

www.british-cars.co.uk/cgi-bin/gen5?runprog=lotusbbs&mode=archiveth&subject=2001&subjectar=2001&thread=2003042120002420897

www.british-cars.co.uk/cgi-bin/gen5?runprog=lotusbbs&mode=archiveth&subject=2050&subjectar=2050&thread=2001110215251424691

On a 111s a decent induction kit (eg hurricane) and a 52mm TB does actually give decent gains.
www.hazelnet.org/rr/index.htm

Back to back, the TB gave the following differences on there own - not much in it.
www.british-cars.co.uk/cgi-bin/gen5?runprog=lotusbbs&mode=archiveth&subject=2001&subjectar=2001&thread=2002110308170914595