Boosted intake

flybird-T · #1 (**permalink**) 07-18-2006, 07:28 PM

Since we all generally agree that the original spica air box is engineered to work excellently with the 2L Alfa engine, I have a 'suppose' question. Specifically about a 1978 2L Alfa spider engine I am considering building for a turbo. With between 7 to 12 lbs of boost, I wonder if the original spica air box can be used? I'm asking, if It is possible for the air box to hold that kind of boost on a street driven engine? and if It would be wise to use or not use the filter inside the air box? Considering the intake on the turbo will also use a cone filter? Any thoughts on this??

flybird-T

turbolarespider · #2 (**permalink**) 07-19-2006, 04:54 AM

It can and it can't.

Strenght wise, I'd be pretty sure that it should be able to hanld the pressure. I know a few people who have tried, and it worked.

It can't- it's very, very difficult to get that can to seal. The above people could make it work, but eventually gave up on a steel tube that had fewer joints to seal up.

For the filter- no, you don't need it if you have a filter in front of the turbo.

Eric

flybird-T · #3 (**permalink**) 07-19-2006, 02:12 PM

Thank you! and Thank you! - turbolarespider, I appreciate your answer, and you have also saved me from a lot of future frustration.

While I have your attention, What is your opinion about a Saab intercooler from the late 80's? Or is there another production unit that would be better?
The turbo is also a T-3 Saab unit from a '87.

Flybird-T

turbolarespider · #4 (**permalink**) 07-20-2006, 04:49 AM

For the pressures you are thinking of, any intercooler will work fine. The issue is trying to find a workable place for it- and whichever you can get to fit will probably be worth the time.

Oh, if you keep looking for options, consider a water-air intercooler- we used one from a Toyota on our turbo car, which ends up having a pretty small radiator in front of the main radiator- nice little package.

Eric

slyalfa · #5 (**permalink**) 07-21-2006, 10:58 AM

you might take out the filters and just weld it up. ther is no need to ever open it up if there is no filters needed. and that would seem to save a lot of time as it fits and mounts well.
and you might want to add a IAT pickup for the ECU too. This is what I did

Kevin A · #6 (**permalink**) 07-30-2006, 05:43 AM

When doing a turbo conversion, what do you use for the intake manifold (the original spica manifold?). And is anyone using megasquirt, what about injectors? Oil cooled, or water cooled turbos?

Just curious, and daydreaming about future projects.

Thanks,
Kevin A
79 Spider
79 Intl Scout
91 Saab 900
00 Saab Viggen
97 BMW F650

turbolarespider · #7 (**permalink**) 07-31-2006, 04:45 AM

Quote:

Originally Posted by Kevin A

When doing a turbo conversion, what do you use for the intake manifold (the original spica manifold?). And is anyone using megasquirt, what about injectors? Oil cooled, or water cooled turbos?

Just curious, and daydreaming about future projects.

Thanks,
Kevin A
79 Spider
79 Intl Scout
91 Saab 900
00 Saab Viggen
97 BMW F650

Canuck Duetto · #8 (**permalink**) 03-30-2007, 09:34 PM

this may sound like a complete noob question but here goes....after reading tons on fuel rails, efi, megasquirt etc......

could one take the carb system off a lets say carb 2l
install original spica manifold ( no pump)
install high pressure fuel pump,
wire the spica manifold and jetts to a megasquirt ?

or am i completely off base..of course turbo comes later...thus EFI is key

or would one be way better off adapting a GSXR manifold and injection system
high pressure fuel pump,
and of course wire that to a megasquirt..

Any thoughts... why dont more people just replace the spica pump with a high pressure fuel pump ? it must be doing way more than pumping gas, therefore can i deduce that the spica manifold and jetting wont work with a megasquirt..

iachella · #9 (**permalink**) 04-04-2007, 09:26 PM

You are not completely off base. But you may not have a complete understanding of the Spica system. It uses injectors, not jets, and those injectors are fed by a 450 psi pump, which is fed by a ~30 psi pump. You can use megasquirt: you remove both pumps, and all the injectors, because they are not electronic. You have to adapt the Spica manifold to accept electronic injectors and fuel rail. You install your EFI pump of the 45 - 50 psi variety, wire the injectors to the megasquirt, a few other minor things, and yes, you have a Spica manifold and a megasquirt system.

Several poeple have done it. Some will modify your Spica manifold to work. There are some posts on this site if you do a search. I want to do it one day, so I've read a lot about it.

I'm not so sure if ITB and turbos go together though. Maybe someone else can comment. I had thought that control of the flow by ITB is moot since there is so much air pressure. Please correct me if I'm wrong with this last part.

Canuck Duetto · #10 (**permalink**) 04-04-2007, 10:03 PM

well..that definately makes for some thinking.....does anyone know about itb with boost? I don know that the pump pressure for the injectors on itb is usally half what normal fuel injection would be........I think this is one of those things that the answer is probably on a honda forum...those guys love itb systems.