Ok Ok dont eat me alive when i ask about Duke and SC or Turbo .
i read the most threads but didnt got the info i wish.

So what if i bolt an Compressor like this here http://cgi.ebay.de/Kompress...QQrdZ1QQcmdZViewItem
on a rebuild duke .

why would i want this ?
i like the real good mileage of my duke but it could have a little more power in the lower rpms

The Question is : will a charged duke fall apart when i respect strictly the 4500/5000RPM Limit and when the pressure isnt too high.
Goal would be more mpg (maybe i could use an other tranny with longer gearratio) Car is already fast (top speed) enough for its lousy brakes so thats not my goal

And yes i know easier is swapping an ecotec or other opel engine , but i dont like the easy way

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1984 Fiero Sport
1987 Fiero <- Ethanol powered Batmobile
1984 Fiero SE
2002 Kia Spectra <-LPG powered family car

*** nuclear winter cures global warming ***

Yes, the duke can't take much more HP, everything about it is just too weak. Instead of going 'weeen' it will go 'pop'

OK you say everything in it is too weak . so when i rebuild me a 88 engine with an S10 head and complete new internals what would be the limiting part ?
if its the Block where is the Limit in RPM / Oilpressure / Boostpressure / Heat or whatever

kepp in mind , my goal is better mpg

my actual engine has :
ported and reconditioned s10 head
polished and ported intake
cold air intake , k&n filter
homebrewed performance exhaust manifold
homebrewed Exhaust ( 4 Tubes )

enlighted the car where i could

and i run 50% bioethanol
iam around 30mpg (most autobahn at 130-140 kph)

I remember reading about someone who successfully turbocharged a Duke. But he used low pressure... I think 4-5 PSI.

I wish I could find the thread where the pics show the wall thickness of an Iron duke, compared to a Super Duty engine.

One look at those pictures and you will completely change your mind about adding any boost to that sorry engine.

The 2.5L is designed to be as light weight as possible. They removed as much material from various parts as they could. i.e. it's a weak engine.
Brand new, regardless of it coming from an S-10 or a Fiero, it's still a weak engine.

If you want to do a 2.5L buildup, you just about have to use Super Duty parts. SD block, head, and complete rotating assembly will stand up to some abuse - but you've just spent more than any number of other engines would cost - if you can even find all the parts still.

You'll shoot your eye out kid. lol

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Whade' "The Duck Formerly Known As Wade" Duck
'87 GT Auto
'88 Ferrario
'84 Indy

quote Originally posted by Formula88: The 2.5L is designed to be as light weight as possible. They removed as much material from various parts as they could. i.e. it's a weak engine. Brand new, regardless of it coming from an S-10 or a Fiero, it's still a weak engine. If you want to do a 2.5L buildup, you just about have to use Super Duty parts. SD block, head, and complete rotating assembly will stand up to some abuse - but you've just spent more than any number of other engines would cost - if you can even find all the parts still.

i thought of weightbalancing all the internals (dont want superduty block or parts , iam not after 1/4 mile performance )

and maybe there is a way that the charger only produce boost in the area from 1000-3000 RPM to increase the fueleconomy in city use
i know with a turbo u have a wastegate but turbos are weak in low rpms

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1984 Fiero Sport
1987 Fiero <- Ethanol powered Batmobile
1984 Fiero SE
2002 Kia Spectra <-LPG powered family car

*** nuclear winter cures global warming ***

I'm all for neat projects pal, but it's just a plain waste of time and money. Once the engine does go, which is a proven fact that it will, you are gunna have all of that invested and be insanely ticked that you wasted it all.

While I agree the Duke may be a little weak for any meaningful boost, I am interested in the blower.

I don't read German, so I don't understand how much they want and the specs they are describing.

Can you translate?

I like the supercharger idea though. Maybe 6 psi with a rev limiter?

Arn

quote Originally posted by Fieromaniac: i thought of weightbalancing all the internals (dont want superduty block or parts , iam not after 1/4 mile performance ) and maybe there is a way that the charger only produce boost in the area from 1000-3000 RPM to increase the fueleconomy in city use i know with a turbo u have a wastegate but turbos are weak in low rpms

So are small 4 bangers with superchargers... Believe me when I say that.

A 2.0L engine with the right sized Turbocharger will reach full boost at a lower RPM than my 2.0 LSJ Supercharged, which starts building real power at 3500rpm... It's called parasitic drag.

Regardless, in an Iron duke, it'll probably blow up with more than 5 pounds anyways... I'll be interested to see the results, make sure you take video.

I think you're talking about a centrifugal supercharger? not a screw type blower as described in the link?

The screw type blower comes on well before 2000 rpm but doesn't reach peak until 3500 or over.

This means that you actually have some boost right off idle albeit not a whole lot, which is actually good for not blowing up engines like too large a shot of nitrous can do.

I'd buy the notion that 5 psi could be the max too.

Arn

If you use low boost with SBC rods, I think you can take it if you keep off the redline. Its a damn-weak engine I can almost piss through, but I think even with modesty like that you can pull it off.

If you are looking at Opel engines, take a look at the LT3 and look for a DOHC head overseas. I'd bet you could get 250 hp with a DOHC head.

[This message has been edited by AP2k (edited 09-11-2007).]

quote Originally posted by Arns85GT: While I agree the Duke may be a little weak for any meaningful boost, I am interested in the blower. I don't read German, so I don't understand how much they want and the specs they are describing. Can you translate? I like the supercharger idea though. Maybe 6 psi with a rev limiter? Arn

as i understand the seller , its the compressor used on the new 1.4 L Turbo compressor VW with 170hp
if you dont push this engine its a good fuel saving engine
I think the compressor disengage in thin vw engine at a specific rpm then the turbo takes over

quote Originally posted by Arns85GT: I think you're talking about a centrifugal supercharger? not a screw type blower as described in the link? The screw type blower comes on well before 2000 rpm but doesn't reach peak until 3500 or over. This means that you actually have some boost right off idle albeit not a whole lot, which is actually good for not blowing up engines like too large a shot of nitrous can do. I'd buy the notion that 5 psi could be the max too. Arn

I'm talking about the Eaton (roots type) blower that comes Stock on my Cobalt SS Supercharged. There isn't lag in boost (instant boost) but there is lag in power as the parasitic drag is overcome by about 3500 RPM.

Ravant from carforums.net says he's charged his duke (cant remember if it was S/C or T/C) but he never intended it to last, he just halfassed the install of it by welding it on i think lol. So far its holding up but he says hes gunna take a vid of 2 of doing a high RPM clutch drop and see what happens lol. He's doing an engine swap anyhow btw.

thats a g60 supercharger is it not? Aren't those scroll type?

A turbo

[This message has been edited by 30+mpg (edited 09-11-2007).]

Are those yours? Whats the statistics?

those look so funny, a duke with plumbing all over the place... I had a weird thought... what are the chances that you could make an ecotec work as a TBI setup with the stock duke TB?

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If you can't be good, be good at it.

quote Originally posted by fierodeletre: those look so funny, a duke with plumbing all over the place... I had a weird thought... what are the chances that you could make an ecotec work as a TBI setup with the stock duke TB?

if you use the 87 88 tbi and ignitionsystem i guess you would have to use the fiero sensors and use the fiero DIS with the ecotec crankshaftsensor
but iam not sure if the new ecotecs have variable camshaft timing if yes , it would be a big Problem i guess.

but even if all other things match , the ecotec would maybe run but miles away from the normal performance (fiero ecm has RPM limit at 5200 ?? )and fuel economy wouldnt be good , not to talk about the emissions

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1984 Fiero Sport
1987 Fiero <- Ethanol powered Batmobile
1984 Fiero SE
2002 Kia Spectra <-LPG powered family car

*** nuclear winter cures global warming ***

[This message has been edited by Fieromaniac (edited 09-12-2007).]

Yeah, but couldn't you tweak it to allow for more rpms, accurate fuel delivery? Might be easier than making the ecotec brain talk to the fiero brain...

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If you can't be good, be good at it.

quote Originally posted by Fieromaniac: if you use the 87 88 tbi and ignitionsystem i guess you would have to use the fiero sensors and use the fiero DIS with the ecotec crankshaftsensor but iam not sure if the new ecotecs have variable camshaft timing if yes , it would be a big Problem i guess. but even if all other things match , the ecotec would maybe run but miles away from the normal performance (fiero ecm has RPM limit at 5200 ?? )and fuel economy wouldnt be good , not to talk about the emissions

Some of them have VVT, such as the Solstice/Sky. The Duke rev limiter is set somewhere in the 6K region IIRC. The GT rev limiter is nonexistent for all practical purposes (32kRPM or so)

Btw, the Duke with the blue intake stuff is Oslo's. I asked him about it and he had put on 1000 miles and he wasnt sure it was going to last much longer.

And what would this project be?

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If you can't be good, be good at it.

quote Originally posted by Fieromaniac: if you use the 87 88 tbi and ignitionsystem i guess you would have to use the fiero sensors and use the fiero DIS with the ecotec crankshaftsensor but iam not sure if the new ecotecs have variable camshaft timing if yes , it would be a big Problem i guess. but even if all other things match , the ecotec would maybe run but miles away from the normal performance (fiero ecm has RPM limit at 5200 ?? )and fuel economy wouldnt be good , not to talk about the emissions

The 2.2 1st Gen Cavi Ecotec does not have VVT, but why would you want to roll back on technology? Once you stuck that ecotec on there, with boost, there would be no going back.

The 2.2L L61 ecotec is not VVT.

I obtained 45-47mpg over 213 miles at avg. speed of 65 and avg.2100rpms with my ecotec + Megasquirt ECM....

Idk how much it cost to do my swap but Id think itd be cheaper than making the duke do the same

If you boost your Duke - good luck. Many people have gone before and have determined (the hard way) that the maximum reliable horsepower from the Duke is 120. Even at that level you're going to greatly shorten the lifetime of the engine.

Almost everything about the Duke is weak - but the weakest part is the crankshaft. It flexes under power and the crank and rod bearings suffer because of it.

Usual result from boosting a Duke: crank flexes under load so much that the bearings start carrying the load on their edges. Hot spots develop, bearings melt down, rod(s) seize to the crank and break - poking big holes in the block.

As others have noted, a swap is much more cost-effective than upgrading the Duke. If you still want to do it, keep the boost down and don't try for more than 120 horsepower. And start with a freshly rebuilt engine - adding boost to a worn Duke is just asking for trouble.

quote Originally posted by Whuffo: If you boost your Duke - good luck. Many people have gone before and have determined (the hard way) that the maximum reliable horsepower from the Duke is 120. Even at that level you're going to greatly shorten the lifetime of the engine. Almost everything about the Duke is weak - but the weakest part is the crankshaft. It flexes under power and the crank and rod bearings suffer because of it. Usual result from boosting a Duke: crank flexes under load so much that the bearings start carrying the load on their edges. Hot spots develop, bearings melt down, rod(s) seize to the crank and break - poking big holes in the block. As others have noted, a swap is much more cost-effective than upgrading the Duke. If you still want to do it, keep the boost down and don't try for more than 120 horsepower. And start with a freshly rebuilt engine - adding boost to a worn Duke is just asking for trouble.

i agree that all boost projects with a duke and the goal to raise the HP will fail

so my idea is to ad an compressor that rise the HP and torque from 1500- 3000 RPM then it disengage
at all the max HP would not climb it would be still at 98hp/4400 RPM
Question is :

- does 98 HP/3000 RPM generate more stress for the Crank than 98HP/4400 RPM ?
- what is the fuelsaving potential of such an partially charged engine
- will the standard oxigensensor controled Fuel/Air Ratio be able to prevent the engine not to run lean ?
or if it will run lean i would ad flashlube (valve cooling system used in propane powered cars) or maybe other valves
- will a performance cam work with my ecoduke idea ( better open / close times for the valves ) or will the fuelconsumption rise

............. i would change the thread name more to : building an partially charged ECO DUKE

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1984 Fiero Sport
1987 Fiero <- Ethanol powered Batmobile
1984 Fiero SE
2002 Kia Spectra <-LPG powered family car

*** nuclear winter cures global warming ***

I'm no expert but this I know. A supercharger or turbo increase power by boosting compression. Raising compression anywhere in the rpm curve increases torque. So far as I know, the speed of high rpm increases strain alright, and heat, but mid-rpm high torque can be just as bad.

When NOS engines blow it usually isn't at particularly high rpms. You see them blow well before top rpm. Same thing. The NOS kicks in and boosted the pressure and BAM

I think that the Duke will need a more gentle boost and 4-5 may be handlable. And it will shorten the life as boost will do. Putting stronger conrods in helps, but that won't help the crank.

I'd say it sounds like fun but I'd take it a little easy.

Arn

quote Originally posted by 30+mpg:

This one is mine.

I experienced all of the weakspots with this engine during my turbo project days. Correct me if I am wrong, but I do not believe that the S-10 cylinder head will fit the Fiero block. It is a small bit larger than the Fiero head. Difference between R and U engines (I think)

Anyway, the head on my engines didn't go, the pistons didn't break, but I did get quite a few holes in the cylinder walls.

I put 3 engines in my Fiero while I was attempting to get a lot of power out of it and each time the failure was through the cylinder walls.

They are Super-Thin! You can hit them with a hammer and they shatter. Pathetic.

If you are serious about making this a reliable engine, you need to use upgraded pistons (hypereutectic should be fine for low boost), upgraded rods that will not break, and either get a forged crankshaft, or have yours cryotreated or something similar to strengthen it up. If you do not beef up the lower end, you will be rebuilding your engine every 2 months... Not fun. I put 4 engines in the car over a 12 month period trying to make it work.

The first engine blew up without even having the turbo! The intake & exhaust were ported, CAI, Head was ported and polished with larger SS valves, nice radius valve job, the block was bored 0.030 over, and we put in higher compression pistons. The engine just couldn't stand up to the extra power of everything. With the work that was done and the way it felt it was well over 120hp, but it didn't stay together long enough to be proven!

Today I am building a 3.4L pushrod from a Camaro. F**K the duke.

quote Originally posted by Fieromaniac: OK you say everything in it is too weak . so when i rebuild me a 88 engine with an S10 head and complete new internals what would be the limiting part ? if its the Block where is the Limit in RPM / Oilpressure / Boostpressure / Heat or whatever kepp in mind , my goal is better mpg

If you are going to replace the heads, block and all the internals...what's the point? You have already done an engine swap, just one piece at a time.

[This message has been edited by jscott1 (edited 09-15-2007).]

Totally true.

Leaves one to contemplate the Ecotech or Q4 if you want to stay with 4 cylinders.

That was real good info on the cylinder wall strength Oslo. That is a whole different issue than conrods etc. Makes eminent sense not to put any money into an engine with that particular weakness IMHO

Arn

Actually it is the exact same issue as the conrods.

The failure point was that something caused the connecting rods to break and they punched all sorts of holes through the cylinder walls. One actually went into the next cylinder!!

So, if you were to use forged heavy duty connecting rods, then the crank will probably break because as stated, it has a lot of flex. It is the next weakest link.

It's like using a kleenex to clean up a blazing fire... It's simply not designed with the purpose of doing so. In the same regard, the stock iron duke crank is not designed with the purpose in mind to hold up to a lot of power. You need to use something that IS!

Maybe a crank from a 2.5L super duty?? I have no idea if that will even work.

[This message has been edited by Oslo (edited 09-15-2007).]

I believe that you could put 5 psi in a fresh sound Duke and run without problems but you will need to change to the larger TB, keep the RPMs below the 4500 RPM redline and convert to Premium fuel. However 5 psi working against only 15 psi of fuel pressure nets you 10 psi of pressure and this could spell problems if you don't develop a method of enrichment (as with a boost referenced fuel pressure regulator.) . If you buy that supercharger make sure that you get a large enough pulley so that the boost doesn't skyrocket. The Duke is not hard to blow if everything isn't working just right. I almost bought an 88 Duke coupe a while back as it rode well and I planned to install a tiny turbo but it never panned out.
I agree with the statement that the horsepower limit on a Duke should be held to about 120 as you can only go so far with a light duty engine- 5 psi of boost should get you there.
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87GT 3.4 Turbo- 0-60 5.2 seconds
2006 3800SC Series III swap in progress
Engine Controls, PCM goodies,
re-programming & odd electronics stuff
" I'M ON THE LOOSE WITHOUT THE JUICE "

[This message has been edited by Dennis LaGrua (edited 09-16-2007).]

Years ago, IRM sold a turbo kit for the duke. I think it was made by HiTech Turbo (?). Jim Sutter discontinued it because of reliability problems. Does anyone remember this kit or know what boost it used?

As Dennis said, it is necessary to add fuel somehow. Using a wideband O2 sensor to tune, you can easily add an extra fuel injector somewhere in the intake piping activated by a boost pressure switch which is what I did. It worked really well.

Ok I am new here as of recently. Was here once before but that was a very long time ago. Anyway I am not new to Fiero's or Dukes. Boosting a Duke is doable in my opinion. If the engine is in stock form and in good condition i suspect low boost might be ok. But if you build from the ground up your odds improve greatly if you look for the right parts. To start off lok for a "T" block. This is not the truck block. Don't ask me what it comes in I don't know. I found mine in one of my Fiero's. Must have been a rebuild by a previous owner. It is somewhat stronger. You will also want a crank out of a 87 DIS Duke. Much stronger. Then get forged rods and pistons and run a low compression ratio, 7-7.5 to1. I have beat the crap out of more dukes than I can count with only one real failure. That was a holed piston due to me setting the timing by ear on a super noisey(Hooker exhaust, no other muffler and no cat. In other words straight exhaust.)engine and bad gas. It detonated a hole the size of a half dollar in one piston. BTW I drove the car for three weeks as is after that. Only took it apart to find out what was wrong. Could have kept running it. Most all of my Dukes have had some HP increase although I can only say by the seat of my pants. This was thru either Exhaust, ignition, or Induction, but mostly all three. I ran a Bosch mechanical port fuel injection set-up on my IMSA mounted on a SD-4 2bbl intake. This was on a worn out Duke that was sitting on the garage floor. Needed an Engine when I had to take my Super Duty out of my IMSA due to worn bearing because the previous owner had no idea how to take care of an engine. Anyway these are my opinions take them for what they are.

quote Originally posted by The_Stickman2: Boosting a Duke is doable in my opinion. If the engine is in stock form and in good condition i suspect low boost might be ok.

It sounds like you know what you are doing, and had a lot of fun with the duke. No doubt boosting a duke is doable...

but most of the young folks on here think you are going to bolt on 100 hp or more to a duke. It aint gonna happen without blowing it up. If you like rebuilding engines and playing around with the duke, I say go for it, but for most people there is a lot more bang for the buck in a totallt different engine, like a 3800, 3.4 or even a 2.8.