MSefi.com read only forum (Jan.15,2018)

Hi,

Can anyone tell me if there were any TBI cars/vans available in the uk?

I am planning a TBI conversion for my 3.4 litre MK2 Jaguar, which is rated at 210hp. I intend to build an adapter and convert the two, two inch SU carbs to TBI.
From the Megasquirt conversion table I calculate that I will need 2x 61.7lb/hour injectors.

Can I use port injectors? the biggest I can see that might be available here are Bosch 0 280 150 403 rated at 49.3 lb/hour (100.6 hp each).

I might even be able to fit two smaller injectors in each carb; is this likely to cause any problems?

Thanks,
Paul

Hi Paul,

I would suggest Googling UK sites for Megasquirt installations. There are plenty of them out there. The chap that runs ExtraEFI (and distributes on this side of the pond - www.extraefi.co.uk), Phil should be able to give you some pointers on your particular installation. Any reason for just using 2 injectors and keeping the carbs? I assume it's a straight six? In which case, why not get rid of the carbs entirely and go for ITB's? One injector per cylinder and I would imagine a lot easier to tune than trying to set up 2 large injectors on a six.

You can pick up bike throttle bodies very cheaply on eBay, as long as you get the ones that separate (ie early GSXR) and they usually come with the injectors, fuel rail attachments, TPS etc. Obviously you'll need to buy 2 sets, and then get a manifold made up by Altiss Engineering or Bogg Brothers.

Good luck!!

Cheers

Darren

Hi Darren,
Thanks for your reply.
I'm trying to keep the car looking as original as possible, so I wanted to keep the carbs.
I was originally planning to weld some port injector bungs on the bottom of the inlet manifold, out of sight and use the carbs as throttle bodies and I may still go that way, but this involves making up bungs and aluminium welding, plus a lot more work than simply making an insert to house the injectors in the carbs.

I have seen several classic cars modified this way on the Internet, so it appears to be a good intermediate way to achieve EFI.

Paul

Can't help much for UK sources or European cars, but I am mid-way thru installing 2 GM TBIs on a 7.2L Chrysler. I am using 2 TBIs from 5.7L GM trucks, perhaps you could use 2 TBIs from a V-6 GM and then tune to suit? These would be peak-and-hold injectors, if that matters to you.

Here are some links:
http://dynamicefi.com/TBI_Fueling.php
http://www.goingfaster.com/spo/tbi.html

The first link has some good info on what TBI units to choose.

I have at least 6 of these units that I have scrounged from junkyards, perhaps I could sell you an incomplete one cheap so that you could see how well it would fit? Also, there is a local junkyard that sells stuff cheap, so if there's a particular GM one you want I could see if they have it.

Hi fury fan,

Thanks for the offer, much appreciated, but I really need to be able to obtain the injectors here, just in case they need to be replaced at some point in the future.
The links are very helpful too.
I have been looking at Side Feed Injectors, which seem to be the type of design best suited to TBI. I have bought some cheep Subaru Impreza WRX turbo ones on Ebay including rails.
They will probably not have enough flow for my application, but they are available up to about 1000cc, so if I design my system around them and test it with the ones I have then I can easily obtain higher flow injectors if everything else comes together.
If I decided to put two in each carb, then the ones I have would be adequate to keep.
If these injectors would physically fit in an adaptor inside a 2 inch SU carb, can you envisage any problems that using two pairs in this way might cause?

Thanks,

Paul

I don't know what your carb size is, but evaluate whether the 2 injectors will be blocking too much airflow thru the throttle bore. You'll have to use your instincts and judgment for this.