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post #1 of 12 (permalink) Old 06-26-2017, 09:01 PM Thread Starter
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Max hp with a turbo

Just have a curious question. What's the max hp can our 2.0 engines achieve daily driveable if you build the motor and turbocharge it. I have a motor I'm wanting to build and I want to achieve 400whp. I just want to know if that is doable while also driving it a couple times a week. I do have a primary daily driver other than this btw. Could our motors achieve higher than 400whp with a turbo build?
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post #2 of 12 (permalink) Old 06-27-2017, 01:27 PM
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At that power level (don't know if it's achievable) you better replace the rods with the super-strong Carellos, and add a girdle to the crank. Also you will need to cross drill the block to provide direct oil to crank bearings 2 and 4.

These engines were designed for about 100 HP. They do OK in full race at 200-250 HP. But 400 HP at the wheels, or 500 HP at the crank, is a lot. Not sure the TX can take that much either, nor the Diff.

Alfa upgraded the drive shaft when they went from 95 HP to over 140 in the 2L engines. You might need to go to a one-piece drive shaft that is even stronger. Drive carefully or twist the axles from the diff to the wheels. You'll really challenge the LSD discs.

Then the body will need a lot of stiffening to take that load too, especially in the Duetto, where body stiffness is essentially in the two side sills under the doors.

Someone stuffed a v6 alfa motor in a Spider, and one guy in Arizona put a Ford small block in.

Just some thoughts.

Robert
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post #3 of 12 (permalink) Old 06-27-2017, 01:47 PM Thread Starter
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I'm mostly looking to achieve 300-350. I know 400 is a lot but I was just seeing if it was doable. I know a lot of things will have to be worked on motor wise.
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post #4 of 12 (permalink) Old 06-27-2017, 02:48 PM
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Originally Posted by Ajhubb12 View Post
I'm mostly looking to achieve 300-350. I know 400 is a lot but I was just seeing if it was doable. I know a lot of things will have to be worked on motor wise.
If you want an idea of what is involved for those power levels, check out the threads about the turbo/supercharged Alfetta in the engine conversion forum. Essentially, what you are looking at:

Stage 1: A good stock motor will take 7-9 PSI and make in the 170whp range without blowing up. Drivetrain should be mostly fine (mine has been), but you will want to add a cage to the driveshaft donut.
Stage 2: A relatively basic Piston/Rods/Liners should take 15-20PSI and make in the 250whp range- 300-350 is in the realm of possibility. You may also want some sort of system to reinforce the liners.
Stage 3: An all out build will likely require a monosleve liner. Look for threads about the "Bonneville" Spider. This can get you into the 500+ club. You'd be looking at a complete replacement of the drivetrain at that point.

Gearing is also an issue 1st-2nd are way too short for a turbo spider. Even at 7psi I ram in to the rev limiter very quick in first and second if I give it full throttle- it often breaks traction as soon as the boost hits.

"Daily driveable" is a matter of opinion. You certainly can make a 400whp turbo 2 liter very driveable, but you will suffer from a decent bit of peakiness. Stay out of boost and it will be a *****cat. In all cases, I'm assuming you will ditch the Spica/Carbs/L-Jet/Motronic and do a good standalone programmable unit. I can share a decent starting point for megasquirt if you are going that route.
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post #5 of 12 (permalink) Old 06-27-2017, 02:58 PM
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It -can- be done....

Contact Jim Steck.


http://www.alfacybersite.com/ACSBonnevilleTurbo.html


Speed is money; How fast can you spend?

71 Spider

Last edited by Lokki; 06-27-2017 at 03:03 PM.
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post #6 of 12 (permalink) Old 06-27-2017, 07:43 PM Thread Starter
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Quote:
Originally Posted by Ajhubb12 View Post
I'm mostly looking to achieve 300-350. I know 400 is a lot but I was just seeing if it was doable. I know a lot of things will have to be worked on motor wise.
If you want an idea of what is involved for those power levels, check out the threads about the turbo/supercharged Alfetta in the engine conversion forum. Essentially, what you are looking at:

Stage 1: A good stock motor will take 7-9 PSI and make in the 170whp range without blowing up. Drivetrain should be mostly fine (mine has been), but you will want to add a cage to the driveshaft donut.
Stage 2: A relatively basic Piston/Rods/Liners should take 15-20PSI and make in the 250whp range- 300-350 is in the realm of possibility. You may also want some sort of system to reinforce the liners.
Stage 3: An all out build will likely require a monosleve liner. Look for threads about the "Bonneville" Spider. This can get you into the 500+ club. You'd be looking at a complete replacement of the drivetrain at that point.

Gearing is also an issue 1st-2nd are way too short for a turbo spider. Even at 7psi I ram in to the rev limiter very quick in first and second if I give it full throttle- it often breaks traction as soon as the boost hits.

"Daily driveable" is a matter of opinion. You certainly can make a 400whp turbo 2 liter very driveable, but you will suffer from a decent bit of peakiness. Stay out of boost and it will be a *****cat. In all cases, I'm assuming you will ditch the Spica/Carbs/L-Jet/Motronic and do a good standalone programmable unit. I can share a decent starting point for megasquirt if you are going that route.
Ok that sounds a lot more promising! I was actually looking into doing the megasquirt. If I can push it to 400 I would love it but 350 was the ultimate goal! I was also planning on running e85 too so I figured that would help out a lot.
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post #7 of 12 (permalink) Old 06-27-2017, 07:46 PM Thread Starter
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Originally Posted by Lokki View Post
It -can- be done....

Contact Jim Steck.


http://www.alfacybersite.com/ACSBonnevilleTurbo.html


Speed is money; How fast can you spend?

Sounds like a plan. I know his will be something that will take a little minute because money is everything but it will be done now that I know it's possible. I figured since someone got one to 650hp, then 400 should be relatively achievable, especially with a turbo.
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post #8 of 12 (permalink) Old 06-27-2017, 08:37 PM Thread Starter
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Also my engine isn't a twin spark engine. Does that change the limits of my hp range?
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post #9 of 12 (permalink) Old 06-27-2017, 10:27 PM
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At this point, you need to do a lot more research on your own with some professional engine builders if you're really serious. You are looking a a ridiculous amount of time and money to produce that kind of power from a Nord. A race-prepped Alfa Nord engine putting out 180 - 200 reliable horsepower is probably going to cost $7,000 to $10,000. Just reworking the head on a race engine will run $2500 or so. What you are talking about in building that kind of engine is going to cost a lot more than a typical race engine and will probably never be reliable enough to drive regularly.

The basic Alfa Nord engine was designed more than 50 years ago. It started at 1300 cc and was ultimately expanded through 2000 cc without a major redesign. Even with with the Twin-Spark head, it never went above 200 or so HP. Once you start going ant serious number above that you need to start looking at serious modifications to the block to keep the cylinder sleeves from moving around and keep the head bolted on. You'll need special headwork and special headgaskets, as well as special sleeve and special pistons, not to mention the turbo and injection systems.

http://www.autocomponenti.com/projec...ew_records.htm

Note that there is no real "off-the-shelf kit" for putting a turbo on an old Nord engine. You will need to find someone who has done the development work and pay them, or spend some years doing your own.

Then there's the fact that Alfa transmissions from 105/115's won't handle that kind of power, the cooling system will have to be modified, and so will the brakes, the diff, and the suspension and probably the chassis.

The bottom line is that, yes, 350 or 400 hp is possible but unless you have some particular need to do it with an Alfa Nord engine, or most 2 liter engines for that matter (Jim Steck had such reasons) , you're crazy.

You can probably build a nice Chevy small block with 5 or 6 liters of displacement and pull 400 hp out of it for $3500 or less, and still drive it every day. If you need that kind of power, that's a much smarter plan. Alfa 105/115 Spiders were never muscle cars, even when they were new.

I posted the link to the Bonneville Alfa to give you some idea of how seriously you would have to take the project to achieve 400 hp. I suspect some wistful daydreaming on your part, and while I don't wish to discourage you, I don't want to lead you on either.

I leave the rest of this discussion to others.

71 Spider

Last edited by Lokki; 06-27-2017 at 10:44 PM.
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post #10 of 12 (permalink) Old 06-28-2017, 01:04 AM
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to quote an Alfaholics article:

“If you want to go crazy, at the race end of things, our race car has got 210 bhp from a Nord 2000cc engine – but you are spending over 10k to get that. The thing is, you can get 180 bhp out of a Nord engine but it will be getting toward the top of its limits within a sensible budget, whereas you can build a 185 bhp Twin Spark engine relatively easily. In fact, you get nearer 190 bhp before you start going really crazy”

Dom - Alfa Spider 1990 S4 - formerly: Alfa 101 Sprint, 2600 Sprint, Montreal - family classics: Jensen Interceptor II, '58 Hooper RR Silver Cloud I, Shadow II, '60 Corvette.
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post #11 of 12 (permalink) Old 06-28-2017, 06:01 AM
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Originally Posted by Lokki View Post
At this point, you need to do a lot more research on your own with some professional engine builders if you're really serious. You are looking a a ridiculous amount of time and money to produce that kind of power from a Nord. A race-prepped Alfa Nord engine putting out 180 - 200 reliable horsepower is probably going to cost $7,000 to $10,000. Just reworking the head on a race engine will run $2500 or so. What you are talking about in building that kind of engine is going to cost a lot more than a typical race engine and will probably never be reliable enough to drive regularly.

The basic Alfa Nord engine was designed more than 50 years ago. It started at 1300 cc and was ultimately expanded through 2000 cc without a major redesign. Even with with the Twin-Spark head, it never went above 200 or so HP. Once you start going ant serious number above that you need to start looking at serious modifications to the block to keep the cylinder sleeves from moving around and keep the head bolted on. You'll need special headwork and special headgaskets, as well as special sleeve and special pistons, not to mention the turbo and injection systems.

Bonneville 2004 - Two Records

Note that there is no real "off-the-shelf kit" for putting a turbo on an old Nord engine. You will need to find someone who has done the development work and pay them, or spend some years doing your own.

Then there's the fact that Alfa transmissions from 105/115's won't handle that kind of power, the cooling system will have to be modified, and so will the brakes, the diff, and the suspension and probably the chassis.

The bottom line is that, yes, 350 or 400 hp is possible but unless you have some particular need to do it with an Alfa Nord engine, or most 2 liter engines for that matter (Jim Steck had such reasons) , you're crazy.

You can probably build a nice Chevy small block with 5 or 6 liters of displacement and pull 400 hp out of it for $3500 or less, and still drive it every day. If you need that kind of power, that's a much smarter plan. Alfa 105/115 Spiders were never muscle cars, even when they were new.

I posted the link to the Bonneville Alfa to give you some idea of how seriously you would have to take the project to achieve 400 hp. I suspect some wistful daydreaming on your part, and while I don't wish to discourage you, I don't want to lead you on either.

I leave the rest of this discussion to others.
Custom turbo setups aren't so complicated that they need years of R&D. The main obstacle is fabrication of the manifold and exhaust components, and the intake manifold & fuel rail for the megasquirt conversion.

The "race prepped" NA motors are not really an applicable comparison. They are working off a totally different paradigm than a turbo build. The motor build itself will actually cost less than high-output NA motor because you don't need it to rev to 8000rpm and can pretty much leave the head alone. Biggest problem is the liners- the cheap way to is to o-ring them to keep them in place- that's what buzzed did for his twin-charged build. At some undefined point however, you need a mono sleeve to have sufficient structural integrity (like the bonneville spider used). Mono sleeve is a $5k proposition by itself.

I think 400hp is way beyond reasonable for something that will be driven outside a special circumstance like the Bonneville Alfa, but a 250hp turbo motor is far from crazy and would make a spider PLENTY spicy. You are looking at 1/4 mile times in the 11s at that power level provided you can put it down- 300+ will put you in the 10s. Heck, Alfa itself made a factory turbo Nord capable of that with minor modifications (in the Alfa 75 Evo).

Speaking of the Alfa 75- one option is to source a factory 1.8 turbo from Europe. That solves the liner problem and by far the better option if you are trying to make HUGE power. The biggest problem with the 1.8T motors is just finding one and getting it shipped over. My biggest worry in is was that there is no way for me to verify that a junkyard pull from some foreign scrapyard is actually a good motor before spending $2k to bring it over.

One thing to consider before thinking about BIG power: you will have to get rid of the Alfa rear end for 400+hp. That means weight (unsprung weight at that)- there's nothing that can handle the power that isn't significantly heavier than the Alfa part. It also means major cutting to get it to fit. It's also essentially impossible to get appropriate gearing for 400hp in an Alfa rear end- you'd likely be unable to give it full throttle until 4th gear with that sort of power with the stock gearing.

Yes, you can do a SBC, but then you are talking most of the Alfa out. Might as well just do a Miata SBC swap- they have ready made kits.

One nice thing about a turbo setup is that you can do it in stages (as I am doing). Right now, I'm just running a basic setup on a stock motor with 7 PSI. I have been slowly working on the brakes, suspension, drive train piecemeal. Once everything else is up to snuff, I'm planning on a built motor with a 250ish whp target. I have no desire for 400. As a final warning, you should know that a turbo spider is by no means a fully rational project. There are far easier/cheaper ways to have a quick roadster.

Last edited by nealric; 06-28-2017 at 07:51 AM.
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post #12 of 12 (permalink) Old 06-28-2017, 08:11 AM
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8:1 with a Steck head and RJR cams will net 285WHP at 1 bar on 93. More is possible but this motor is daily driver reliable with around 60K turbo (s)miles.

Your best route IMO would be to source a complete 1.8T from yurrup. Add an aftermarket ECU and a little bigger (and better) turbo, injectors and you will have more than enough power. You will be in for about $7500. A comprehensive, premium component 2.0 build you are north of $20K easily.
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