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Discussion Starter #1
Ok, I am getting in the mood for some more HP under the hood. I am planning on building a sleeper S4 Spider and spank some people on the streets of Lexington.

But seriously, the goal will be to build an engine that will:
1. not blow up
2. run on premium pump gas
3. not cost a fortune
4. create between 200-225 hp
5. retain the bottom end stock

Am I correct that the stock compression on the S4 is 10:1? And has anyone supercharged a S4 in the stock configuration on the motor?

From my reading on the net, I am thinking that one could get buy pushing 10 psi with a supercharger on a 10:1 engine and still use pump gas. No doubt that going lower compression would be safer, but I am not interested in building one from the ground up unless it just comes to that expense. A new head with oversized valves, P & P, cams, and high rev valve springs will be added along with exhaust to complement the supercharger. Emmissions not a concern. And if the stock fuel system cannot complete the task, a new one of those will be added (any advice appreciated).

Finally, can someone outline the benefits/drawbacks between turbo and supercharging? And, it seems to me that supercharging would be an easier install.....any opinions on that? Finally, can anyone provide a roadmap on the process and pitfalls to avoid?

Best Regards,
John M
 

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John M said:
Finally, can someone outline the benefits/drawbacks between turbo and supercharging? And, it seems to me that supercharging would be an easier install.....any opinions on that? Finally, can anyone provide a roadmap on the process and pitfalls to avoid?

Best Regards,
John M
Supercharging and Turbocharging are both difficult to do with out the proper tools. drawbacks of a supercharger is that it takes power to make power. Benefits is that you still will have some extra ponies under the hood. Drawbacks of Turbocharging is that the engine gets real hot and needs to be cooled down (might need alluminum radiator, electric fan etc). Benefits is that after you finish the hard part of cooling etc.. you will have a car with massive power.
I hope this helps
 

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First off... "**** John, I like how you think"!!

Series 4 is indeed 10:1 CR

Benefit of Supercharger is that you have boost immediately, but you are using some of the power generated to spin the supercharger.

Turbos have to spin up so boost doesn't kick in until you're in the upper revs ( varies based on the setup). Since turbos spin off of exhaust gas, there is no power loss.

Both will generate greater amounts of heat and at 10 psi you probably need an intercooler.

Most important, its very easy to blow up an engine! It really takes some serious tuning knowledge to boost successfully.

I've been looking into boosting my eclipse so most of my knowledge pertains to a 6 cylinder mitsubishi engine (with MUCH weaker internals than an Alfa 2 liter). The general theory is the same, but the particulars will be very different.

I can't wait to hear your results if you move forward on this. This is the year of suspension tuning for my spider, next year I start looking at making "mAd POwah, yo" :rolleyes:
 

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Either way, you will have to do some engine work. I think a boosted 10:1 engine would have a tough time living, especially with pump fuel. 9:1 can work, and 8:1 is a piece of cake to make work (our turbo Spider has that).

To make it work reasonably well, you WILL need an aftermarket EFI controller, as the stock one would not like boost at all. And you will need a cooling system capable of rejecting 250hp of heat. That is for whichever you choose...

I've looked at both for a long time, and if you have an A/C bracket, its possible that the supercharged installation will be easier, as you can put it where the compressor would normally be. Our turbo is supported by a rod to the back of the 19mm alternator bolt, works fine.

Both will require some custom intake plumbing, but the turbo will also reqire water cooling and oil supply and drain- not too hard, but you must get it done right.

With the later cars (after '72) the brake booster is a problem when packaging the exhaust and turbo- it sits out and blocks a lot. Plus the heat soak is an issue, I'm sure if we really beat on our car, we would blister paint eventually.

I would suggest going with a supercharger. And call Jim Steck, he is working on a blower kit for Alfas.

The nice thing about 200-225 hp is that quite a few of the pieces can be re-used- clutch, fuel system...



Eric
 

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here's a question. What is the hp on a stock spider oh, let's say a '79 Veloce? And part B (there's always a part B) Would that differ from say a 91' Spider?

:cool:

Turbolare, what kind of cooling system are you using now?

Thanks.
 

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The V6 would require too much surgery to fit, and finding the gearbox would have been big$$$. Remember, we did this car for $2002, so going the cheap way was how it had to be done.

Sarah- stock '79 makes something like 105-115hp, I think the very last ones made closer to 130hp.

I think ours makes something close to 200hp, as we have done the 1/4 mile in 14.12 sec.

And it's a stock cooling system, which is not good enough. It overheats just like yours, especially in traffic. I think I'm going to experiment with some plates to reduce the recirculation of the air.

We have some new pictures of the car from the '03 challenge, and it was also at the convention last week.

Reposting the cheap details:
Engine- stock pistons machined to 8:1, cross drilled #2 & #4 main, wire in liner for better seal, stock rods and crank, SPICA head modified for Bosch intake (injector pockets), stock cams, Bosch intake, Besic manifold that was given, turbo from Chrysler, intercooler from Toyota, fuel injection from Electromotive.
Car- W&D suspension, Mustang aftermarket wheels, Kuhmo tires, no top, no windows, no consol, no radio, no bumpers.

Fun car to make.

Eric
 

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Good to know, Eric.

Thanks for the info! My Spider is pulling roughly 150 hp with what the previous owner did to the engine and other things, but obviously at the sacrifice of maintaining normal temps. It's still wonderful to have pick up in 5th gear! I bought my spider after driving a Toyota pick up for seven years that had no pick up, it could go over curbs and four wheelin' in the snow, but passing someone in a hurry was NOT an option. Nice to have that 'umph' behind you.
 

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turbolarespider said:
The V6 would require too much surgery to fit, and finding the gearbox would have been big$$$. Remember, we did this car for $2002, so going the cheap way was how it had to be done.
Eric
Eric
There was a guy in Georgia that installed a 2.5 liter 6 cylinder milano engine in a GTV but i don't know what transmission he used. And there is also a local guy that has a alfa shop that installed the same engine but used a Maserati biturbo transmission to handle the power (don't know if that's good to do):(
 

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Discussion Starter #12
First of all, thanks for the many responses and I hope to hear more!

120...Excellent site, I may give them a call.

John Paradiso.....Well, I am shopping for the 91-94 now. I think I have found the car down in FL for the upgrade.

Eric.....Thanks for sharing your experience. So it sounds like a piston swap will be instore. Anyone making the low compression pistons, or will it be a custom job? I think the intercooler will be a must either way. It does seem that supercharging might be less challenging in regards to space. I have consulted Jim Steck in the past and I will see if he is game on this project. I know that he is not interested in trying to blow a high compression motor.

GTV4EVR.....on going V6, unless you are tearing into the motor to upgrade it internally you are not getting much bang for the buck. And if you take a look at those pics of Spiders w/ the V6 conversion....just no room for anything else. It does seem to be a great conversion to get to the 150hp mark w/o building an engine.

In regards to the strength of our components, Jim Steck told me in the past that once you get up into the 250HP range, things start breaking and need to be upgraded. Steck is Mr. Engine on the Bonnieville Spider. So....I am thinking stock rebuilt tranny and rear diff should be great for 200-225hp. What do you think Eric?

Eric, I think you need to make a posting and share all that turbo knowledge! I think a lot of the people on the board would love to hear your experience and what all you had to do to build your car.

Best Regards,
John M
 

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John,

I know what you mean about space around the engine. There is someone here in Toronto with one of these beasts. I don't know a lot about the V6s, but I thought he said it was in the 200hp range (3.0).

Ken
 

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Discussion Starter #14
Hey Ken:

From the ones I have seen on the web, they were the 150hp. I have not seen the 3.0 conversion......yes that would be nice and worth the buck!

Best Regards,
John M
 

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Cheap Horsepower

Well for my HP upgrade with excellent driveability and not much weight added, I am starting a 2.0 TS upgrade. Motor was obtained for about 1K delivered, additionals like Steck TS headers, new dist for less than $500, and the engine is close to drop in with oil pan change, water pump change and some wiring adjustments. Stock HP is about 160 small mods could increase to 190.
 

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Discussion Starter #16 (Edited)
That is a great conversion. For the spider I believe it requires modification to the hood.....well at least the one outlined on the web. You will have to give us a run down on that conversion.

Best Regards,
John M
 

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I LOOVE the TS conversion, and may even do one, with my wife's current suggestion of more power... Jim is finishing up one right now.

If you are a member of AROC, dig through your past issues, I think it was July '02, I wrote a big article about the car in the "Owner"- for the most part, Jim assembled the bottom of the engine.

He and I work together on this Bonneville thing, I try to keep him up to date on the state of the art in the industry, and give calibration advice. Hopefully, I will help find a properly sized turbo for Bonnie.

Our pistons were "custom"- stuck in a lathe, and cut from 9:1 to 8:1. And if you read the article about Calloway's GTV6's, he did the same thing. Stock rods, not even new bearings. If I were doing this for real, I would have done a lot different, but when there is a serious budget contraint, odd compromises are made ;)

Jim also epoxied in the liners for block stiffness. Actually, the only serious problem we continue to have is the darn dip stick- keeps coming out. And that our manifold has a nice little crack that likes to stay.

If you kept the boost below 6psi, with the later engine's VCT, you should get some pretty nice performance w/o an intercooler. The Spider's package space is a MAJOR pain in the rear to get around. If it were a GT or Berlina, easy, but even that Toyota water intercooler that fits almost perfectly is a problem in the Spider....

Eric
 

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Discussion Starter #18
Hey Eric:

Great info. If i kept the psi at 6 w/ stock 10:1 pistons, and build up the head and exhaust, what hp output do you think I would achieve at the crank as compared to the 129 stock for the S4? Would the stock fuel/ignition keep up with this pressure? And am I correct that the TS does not fit beneath the stock hood of the Spider?

Best Regards,
John M

BTW I just emailed Jim to see if he might be interested in taking the project on.
 

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John
That is a lot of compression for boosting. Even 6psi... I think you would be better off with 9:1 which is pretty easy to find in an umolested engine.

IF you could find 110 octane fuel, I would think upwards of 180 hp would be reasonable. But I think the ignition would not be done correctly, as I'm sure Bosch is the same as we are here at F... Which means that above the normal operating conditions, the computer is not calibrated. So while the fuel might be close (not sure), I would think that the ignition would clip at whatever wide open is at sea level (0 boost). Very dangerous...

If you want this to last for some time, there are a number of things you'll want to do with the block anyway, especially since you have to drill into it for oil and water to the turbo.

Keep that head, though- Jim and I have been talking about the VCT, and I know its a cool feature to have with boosted engines (from some local dyno data...). Most aftermarket EFI's have an aux output, that could easily be set up to control the 2 position system on your engine.

Oh, and the TS WILL fit in a Spider, a guy out in San Franciso has done it. Not easy, but very rewarding. The turbo might have similar clearence issues anyway.
Eric
 
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