Hi CHaps,

thinking about sticking my engine on mega squirt just for the hell of it. Ages ago i saw some lotus throttle boddies on ebay which bolt straight onto a webber style maifold.. do you know if any other cars came with these types of throttle boddy assemmbelies which will fit new style common injectors

Or is bike carbs the best route? quite fancied using my webber manifold from a cost pespective as i know you have to get a special manifold to fit the bike carbs

any advice on the best route to take would be appritiated

Rich

Rich,
I've converted from Weber 45s to GSXR bodies and I've re-used the weber manfold. I had the adapters machined for the GSXR bodies and re-spaced the bodies.



I did what I thought was the cheapest and simplest solution.

The best feature of EFI has to be pulling smoothly from 1000rpm in fifth at 30mph through to flat out

u2u me if that looks like what you are thinking of and need more info

Paul

Just search ebay for 'throttle bodies' and take your pick from the bike ones up to 45mm!!

Check this one out:
http://cgi.ebay.co.uk/YAMAHA-R1-YZF-04-05-06-THROTTLE-BODIES-LIKE-NEW_W0QQitemZ260008175419QQihZ016QQcategoryZ10490QQrdZ1QQcmdZViewItem

[Edited on 15/7/06 by coozer]

the yamaha ones look like they come in twins which might make them tricky to space out over the manifold. - is this right?

your installation with the GSXR ones looks great - do they separate easily or were they in pairs and you have to cut them apart to space them out right

also how do you know your buying the correct size boddies, i would expect you need each one to be 45mm ID to tie in with the carbs that ill be replaceing - is this right??

also - did you guys start off with a map or run closed loop - can mega squirt do this ok ?

Rich,

The GSXR bodies ones I have come as 4 castings and simply unbolt. I spaced them with washers but i've seen people turn up some spacers on a lathe.

There are versions of GSXR bodies that come as 2 castings and I wouldn't like to say how easy or hard it is to cut and shut them..
Easiest has to be getting the ones with 4 castings.

I've got 42mm bodies and my manifold was a 40mm (I know I had weber 45's on before but I didn't fit them LOL) so I just blended the manifold that extra mm to make a smooth fit.
I'm guessing a smooth blend is best no mater what size the bodies are.

I did my full throttle mapping with a friend driving and a wideband lambda senor. Since then I've logged a lot of data with a narow band to do the cruise map points. Megasquirt can do closed loop and helps tuning loads.

Paul.

Just remember that 40+mm carbs will have a 30+mm a choke so you don't need huge TBs. Smaller will give better low end response and bigger will give more top end potential. 42-45mm being typical. Too big on a carb is worse than too big on injection as you can compensate with the injectors more easily.

cheers for that
im thinking im gonna go for a smaller size of TB maybe gain more area under the curve that way by keeping up the mixture velocity into the engine

spose its all about top end anyway using such a small length primaries on the manifold, its too bad you cant get a longer one in the mk engine bay

Im well looking forward to getting mapping on it.

Where did you guys pick up the sensors for the system ? Modeos and stuff ? i know its EDIS - and what is a VR sensor is that a funny name for a crank or cam sensor or somthing - ive never heard of 1 b4

Cheers

Rich