Turbos!!

[James Seabolt <jseabolt@domain.elided>]

I'm glad to see that the Italian car digest is coming out on a regular basis
now. My note proved my theory. 

I just wanted to get you guys wound up so people would start sending
articles in!

I haven't contributed anything lately because I figured you guys were burnt
out from me talking about Superchargers and trying to squeeze more HP from a
stock engine. But I got lots of responses so maybe not and seems like
performance upgrades always starts threads.

I still have this thing on my mind.

Most of the letters I received suggested I instal high compression pistons,
performance cams, have the head polished, etc.

Ok here's the deal. The engine I have was rebuilt 4 years ago so I really
think it's a waste to tear it down. I've spent $450 on a new air flow meter
and $200 on a fuel pump so I don't want to junk my fuel injection system either.
 
I've got a spare 2 liter block which I could build so if anyone wants to buy
a rebuilt 2 liter engine with 30,000 miles on it, make me a good deal and I
might consider.

So basically I want to start with a stock engine, install a Supercharger or
Turbo and then if I see the need, I'll work my way up fron there.

I think of installing either of these two items of a regular basis. I have
hit a snag on the supercharger. I haven't figured out a way to drive it.
Everybody I've talked to says it can't be driven by a V-belt. I guess
because it would slip. Which means I would probably have to change every
pulley to a serpentine system just for the supercharger.

So I am considering a turbo. I found a really good source for Turbos. I can
get a Garrett TO3 for $210.00 . I beleive this is a refurbished unit because
I read that a new TO3 costs around $700.
 
A guy who used to attend our club meetings brought his 82 Renault Fuego one
day. He installed a Garrett TO2 or TO3 turbo among a few other things.

At 2500 rmps the turbo would kick in. At this point the rear wheel would
start spinning and the clutch would slip. Which sounds like it's developing
too much torque but was still impressive.

When the turbo would kick in, there was the sudden rush of power yet the
tachometer stayed at 2500 rmps! It was a really wierd feeling.

I've driven many Saab 900 turbos and all were a dog compared to my Father's
BMW 325. But this car impressed me.

I think a turbo would probably be easier to install than a supercharger.

OK here's a few questions.  

I was told that I need to keep my RMPS wound up in order for the turbo to
work. Which I am willing to do. That means going higher than 4000 rmps as a
shift point.

Installing the turbo: 

Has anyone seen a Garrett TO3 turbo ? I am wondering if it looks anything
like the Borg Warner unit used on the "original" turbo Spiders. I'm
wondering how it would mount up to the exhaust mainfold. How would I mount it?

Controlling detonation: 

I've heard this is a problem with turbocharged engines. To combat this
problem on the Turbo Spiders, Legend industries (the company which carried
out the conversions) used a funky boost setup which basically raised the
fuel pressure at WOT by means of the throttle positioning switch and the
coolant termperature sensor. It also used an advance limiter inside the
distributor.

I think this setup was rather outrageous and have no plans to track down one
of these setups. I beleive modern cars use a knock sensor to control
detonation. Does anyone know of any "simple" aftermarket knock sensor which
fits between the control module and the ignition coil? Jacobs electronics
may sell them.

Anyway to rig one up from a VW?

Intercooler:

I think there is enough room to mount an intercooler just before the
throttle body. Some hood modifications will need to be done for this. That
is if I can find one thin enough to fit between the hood and camboxes. This
may come later once I get the turbo setup and working properly.

Ductwork:

I assume that the "air" inlet and outlet snouts on the turbo get very hot so
a common rubber pipe connector from a hardware store will melt. Anyone know
where I can get these any the piping needed for the ductwork? What are these
connectors made of?

I have only witnessed one turbo spider in my lifetime. It appeared that the
owner had made an inlet and outlet hose out of fiberglass instead of
purchasing the a replacement hose which sells for something like $400. 

Roger Hoffman, if your reading this, ask Mark Cantemessa about this.

Oil:

On the "original" turbo spiders, a nipple was brazed onto the side of the
oilpan for the oil return line. Althought I am willing to remove the oilpan,
I am wondering if I could just install one of those filter adapters for an
oil cooler and plumb the oil that way?

Is there any harm in doing it this way? I assume that "fresh" oil should
circulate through the cooler, then to the turbo and then back to the engine.

I wonder how much trash is generated by the turbo. If this might cause the
engine to wear out faster because it's getting oil first used by the turbo
before it's filtered. 

Fuel:

Do I need to compensate for the (extra air) or compressed air by increasing
fuel pressure at the same time? I know this sounds strange that I want to
install such a device, but what exactly does a turbo/supercharger do? I know
it forces compressed air into the engine and raises HP and torque but when
this happens, what exactly is going on inside the engine? I think I know the
answer but if someone could explain this, please do.

As far as I know the original Spiders fuel system was not modified (except
to prevent detonation) so I assume I that I don't need to raise the fuel
pressure or get anymore fuel flow when the turbo kicks in. That is if I find
a knock sensor.

I've heard of several ways to increase fuel flow but cannot find much info.
Some of the stuff I've heard are :

Air flow meter from a Datsun 280Z
BMW fuel injectors
Bigger fuel pump (Paxton's 45 psi, BMW maybe)
Fuel pressure regulator which allows full fuel pressure at WOT, normal fuel
pressure at idle and part-open throttle. I was told that a company called
MicroDynamics or Micro- something sold these.

Any ideas here?  

I think I can probably keep this conversion under $500-$700. This is just a
guess and will probably run more.

thanks.






James Seabolt -----> mailto:jseabolt@domain.elided
Webpage: http://pages.preferred.com/~jseabolt

United States

1980 FIAT 2000 Spider (injected)
1981 FIAT X 1/9 (Injected)
1994 JEEP Wrangler (2.5l )
1976 Chevrolet Pickup (454 Big Block)