Turbo charging a Scorpion

[Uni]

Hello!

I am investigating turbo charging my '76 Scorp and am looking for 150+ HP. Rather than re- inventing the wheel, I thought I'd ask those of you who are "in the know" for some details about the process. Specifically, I would like to know:

1) how many HP and/or psi of boost are possible w/ the stock injectors, and
2) what are the options for getting more fuel while still using the original ECU.
3)If I need to upgrade the injectors, what is the easiest upgrade?
4) What is the ability of the ECU to adapt to more fuel and can the O2 sensor compensate sufficiently???

Appreciating any advice,

Niels Uni

[SubGothius]

Injectors? ECU? Stock Scorps never had any of that kit, so shall we presume yours has a later-model Beta's 2.0L EFI lump transplanted into it? Sorry, don't mean to give you the business, just helps to establish a baseline of exactly what we're working with. ;)

[Will]

First: What Tye said, then:

150HP is pretty aggressive maintaining the stock FI. And, you didn't inform us which FI you are using, the Beta or FIAT.

You should probably get in touch with James Seaboldt (sp?-sorry James!)on mirafiori.com, as he did a 124 spider and a Yugo I think.

1) Theoretically, stock injectors could do 6 or 7 lbs boost. they are Bosch injectors, and can be run at a pretty high duty cycle, but then again the last thing you want is for a turbo to go lean on you under full boost!

2) Raising the fuel pressure or using a rising-rate regulator, increasing the size of the injectors, trimming or prcessing the AFM signal, adding additional injectors, any combination of the above.

3) Easiest upgrade is to buy a new set of matched, bigger injectors. Cheapest upgrade is to pull them off something with a larger per-cylinder displacement. There's a chart here:
http://www.savetheledges.org/test/AVS/images/tech/fitable1.html
and a calculator at RC engineering:
http://www.rceng.com/technical.htm

4) Limited, and you really don't want the 02 sensor to compenste under boost- better off in open loop and safely above stoich IMO. Other alternatives would include any one of a number of other aftermarket fuel controllers, which I would advise you take a good look at before proceeding. I have no doubt you could get your 150 HP out of the stock system, but since it lacks the ability to be easily retuned, it's going to cost you a lot of time and effort trying to find workarounds that approximate the fuel delivery you want.
An aftermarket system makes things much simpler.

If you can afford the $2500 or so, the Electromotive or Haltech are (again, just my opinion) decent options. For those on a really tight budget, the Megasquirt system is an alternative. It takes a little more to figure out how to get this one set up, but there are several FIAT/Lancia guys already ruinning one that can probably provide you with helpful advice and a base map to get you started. It's not necessarily the $300 plug-n-play system some people think it is though. I've got about $800 into mine so far, and another $400 or so remaining for all the bits I want to complete it. It took me about two months just to figure out what version of the hardware and software to go with. Of course, it took me about two months to figure out how to make the VCR clock stop blinking too. Ain't electrical tape great :)

[Wallace]

I've done it !

And the advice ? Do it right or it gets very expensive.

I used carbs which was not the best way - EFI is better all round - period. But get the right injectors AND a mappable aftermarket ECU. Use 8 valve Thema pistons to lower the CR to something reasonable. Fit an oil cooler AND an intercooler. You should get a easy 200bhp out of a 2000 running 12psi or so boost - and not too much lag either.

The main problem your have is making/getting hold of a manifold. There is enough room to bolt on a T3 - but it's tight. It has to be thickwall tubing or else it will fracture.

Otherwise the standard Monte/scorp block will handle the power. Use a Thema clutch and buy a spare gear box (maybe VX one which has a higher bax axle ratio).

Be prepaired to spend lots of time and cash - especially if you don't have any fabrication plant available.

Oh yes. One more thing.

It is SERIOUSLY worth it !

[Uni]

Thank you gentlemen for your replies.

I realize that in my enthousiasm I omitted some critical details.... I apologize.

I have an 1800cc Scorp and transplanted a Beta FI system to it.

Niels

[Jim Fierst]

Since I was where you are at some 4 years ago or so I will offer some observations . I have a 1982 Fiat Spider which is turbocharged and a pleasure to drive. It is very similiar to Jim Seabold's car and uses some of the same techniques. Jim's car dyno'd at 122 rear wheel horsepower and is probably close to 150 HP as is mine. He drove mine but I never drove his so he can comment on the similarity.
My first suggestion is that you read as much information as you can find on the subject to understand what systems have to be managed. Fuel, lubrication, cooling, and ignition are all effected..Corky Bell's Maximum Boost book is a little dated but a good start.
If you want a 200 HP car running 15 lbs.of boost be prepared to spend cubic money.Will and Wallace already mentioned some of the requirements there.
If you are willing to pull your horns in a little you can get by with
the stock FI system.It begins to be maxed out at 7-9 pounds of boost .
An adjustabile FPR running 40psi will work o.k. There is a technioque for causing the FI to go dead rich under boost the Seabold developed that seems to work fine. Ignition management can be done with boost sensitive retard systems like MSD system. These are acceptable solutions for low boost applications .
Having owned a Scorpion I can tell you that unless you can canabilize one that was already turbo'd you will have to fabricate lots of pieces or have the re$ources to have them made. It is no small undertaking.
Just my opinion. Jim

[guy]

hallo,why making it difficult ,a complete workingThema Turbo engine with all parts and 80000 km cost you 1500 euro I have one in stock www.abarth-gmr.be our guy@abarth-gmr.be

[Wallace]

One good reason - it goes in back to front !

Ken Haven's done it like that - I prefered to keep the hot end where it is !

Big advantage is that you could fit the Integrale 16 valve engine . .