Ok I was thinking would it be better to turbo charge the 2.5 iron duke or to just do the engine swap to a 5.7 chevy 350?

Turboing the 2.5 is a sure way to need a swap soon. They just won't take much and they hate higher rpms.

I agree, a 2.5 wont last long under boost. I have read many threads where people had to try and put alot of money into it just to have it fail.

There are alot of other swaps that have been done and proven many times ! Out of your choices I say 350, but it will get expensive too, I think there are better options.

Turbo a 2.5? How much horsepower do you expect to make? Around 140, you might as well just find a 3.4 or old 2.8 and install that. Certainly a 350 is going to give you a huge performance increase, but there is more work and money involved.

It's like saying do you want apples or oranges. The difference is that great and you have to decide what you want.

3800 NA

Turbo pushrod 2.2, because the parts are out there, and I haven't seen anyone do it in a Fiero yet.

Ok thanks guys. Also i have a supercharger that i purchased off Thomas Knight. I only need it to boost 5lbs of boost so i wont need to mod anything.Would this work??I wont blow the engine or anything>?

on the contrary, you WILL blow the motor. the bottom end is not strong AT ALL.

350 swap would be super easy in the wiring department and super fun to drive. Its kind of heavy, specially with an auto tranny, it sucks gas, but the hp mods are endless and cheap. Still, worth it.

3800 N/a, Not as fast as the s/c version but still freaking awesome. Great on gas. Axles will probably be the worst part of the swap if you go with the 4t65ehd auto. Wiring is way worse than a 350 but is doable. Ryan gick from sinister performance has diagrams on how to hook it up wire by wire on his website.

There is so much information on both swaps, just use the search function. Darkhorizon has a thread around here Everything3800 specific.

Hope this helps

when i had my duke engine. i thought about putting a little turbo swift turbo on the duke and run maybe 2 or so psi. keeping the boost low doesnt give you much performence gain. but im sure it will last longer then running higher boost.
i know dukes could handle 110hp. they had that much in the S10s. but i dont think 2 psi will bring you up to 110hp. just give it a little extra power with out having to port the heads and all that fancy stuff. but you might have to fiddle around with the tuning alittle if you wanted boost.

cheapest way to get more power from the duke would be sell the engine. and install a 2.8. that right there will give you more tq and more hp in stock form then you can get with boosting a 2.5. and be reliable. there are more aftermarket parts for the 2.8. not a whole lot but much more then the 2.5
you could get 160hp easy with a 2.8 with porting. better flowing exhaust and a cam swap.

you could do the 350. and have LOTS of power. but is more expansive. if you shopped around and check the malls. people sometimes sell there adapter plates needed for the swap. 350s are dirt cheap to buy. there everywhere. just getting it installed is the expensive part. and your transmission will most likely not hold up very long if you tend to mash on it at stop lights.

the 3.8 engines are very well documented on the forum and can be done under $1000 if you do the work your self. (building your own engine mounts and wiring and such) it has been done.
another option you could do is install the 4.9 V8. thos as well are very well documented here also. both thos engine dont need an engine adapter to bold to the transmission. and can be done fairly cheap if you do the work yourself. the 350 can be done cheap as well. but i find it to be more of a challenge. but it can be done if you shop around rebuild kits for the 350 are dirt cheap also.

it just comes down to what you want.

Never use Duke and Performance in the same sentence. Did I just break my own Rule Number 1?

quote Originally posted by josef644: Never use Duke and Performance in the same sentence. Did I just break my own Rule Number 1?

LOL! The Duke was designed for Fuel Economy, thats it. If you wanted a perfromance duke, a Super Duty 2.7 would be it, but those are pretty expensive and hard to come by sometimes. A Quad 4 with a Turbo would be a fun, High Revving 4 Banger. For the money you would sink into the duke or the Super Duty, you could buy a SC or Turbo Ecotec. I don't like to throw Chevy 350's in Fiero because of weight and the money it costs to do it. If you where to go the V8 route, I would go with an Aluminum Chevy V8 like an LS1 or you could go with the Northstar Engine from Cadillac. But those options are alittle pricey.

If I can show a dyno slip, can I have ten dollars from every person on this forum who (ignorantly, without any firsthand experience) claims that the Duke cannot make stock 2.8 power, or will immediately explode if set up to make more power than a 2.8?

Terms of the deal:
No, none, zero Superduty parts used.
$10 from every 2.5 trash-talking member on PFF.

Here's my build:
http://s892.photobucket.com...20Rebuild/?start=all

Just to provide fair warning...it needed a 454 TBI injector dropped into the pod to deliver sufficient fuel.

How many takers?

Most turbo'd 2 liter setups seem to end up around 180-220 HP. My 3800 NA over 200 and looks like it was made there. Stone bridge reliabilty.

quote Originally posted by KurtAKX: If I can show a dyno slip, can I have ten dollars from every person on this forum who (ignorantly, without any firsthand experience) claims that the Duke cannot make stock 2.8 power, or will immediately explode if set up to make more power than a 2.8? Terms of the deal: No, none, zero Superduty parts used. $10 from every 2.5 trash-talking member on PFF. Here's my build: http://s892.photobucket.com...20Rebuild/?start=all Just to provide fair warning...it needed a 454 TBI injector dropped into the pod to deliver sufficient fuel. How many takers?

Not arguing that a Duke can be built to make some decent power. My only qusetion is how many dollars did it take to get it there?

I tried not to keep count, but I think its somewhere around the cost of an Archie econo kit plus electric water pump. (not including the SBC engine, peripherals, etc)

There's half a set of $200 SBC pistons = $100
Half a $70 set of Summit Racing pushrods = $35
1/2" head studs which on ebay = $70
ARP rod bolts that roughly = $40
Half a set of $100 SBC moly rings = $50
Four Olds 350 intake valves = $32
Half a $65 set of COMP 981 valve springs = $33
Half a set of ARP rocker studs = $42
Fancy 3/8 poly-lock nuts set of 8 = $40
Big cam *I went all out and spec'd my own grind = $334
Some cheap COMP 1261 rocker arms, gaskets, bearings, etc...
Hundreds in machine work, most of it standard rebuild stuff (with a couple small tricks)...
Hooker Header (there's someone on here making a copy if you can't find an original)
Holley intake (or Edelbrock, or Clifford, or Offy, or whatever you have lying around)
Holley TBI (but I've been doing some research and it looks like you could just use a 82-84 crossfire injection TBI to get a large bore)
Bigger fuel pump to handle the increased flow (don't really count this expense since I did this when my stock FP died)
EBL Flash
Random magic...

[This message has been edited by KurtAKX (edited 01-16-2011).]

quote Originally posted by KurtAKX: If I can show a dyno slip, can I have ten dollars from every person on this forum who (ignorantly, without any firsthand experience) claims that the Duke cannot make stock 2.8 power, or will immediately explode if set up to make more power than a 2.8? Terms of the deal: No, none, zero Superduty parts used. $10 from every 2.5 trash-talking member on PFF. Here's my build: http://s892.photobucket.com...20Rebuild/?start=all Just to provide fair warning...it needed a 454 TBI injector dropped into the pod to deliver sufficient fuel. How many takers?

Not knocking the Duke, I've had a couple good ones. But your claim of equalling a 2.8 is only talking 140 HP. Damn nice looking build, BTW.

quote Originally posted by KurtAKX: If I can show a dyno slip, can I have ten dollars from every person on this forum who (ignorantly, without any firsthand experience) claims that the Duke cannot make stock 2.8 power, or will immediately explode if set up to make more power than a 2.8? Terms of the deal: No, none, zero Superduty parts used. $10 from every 2.5 trash-talking member on PFF. Here's my build: http://s892.photobucket.com...20Rebuild/?start=all Just to provide fair warning...it needed a 454 TBI injector dropped into the pod to deliver sufficient fuel. How many takers?

What you say may be true, but to take a STOCK TIRED duke and putting a turbo on it is still not a good idea. What happened to the early turbo kits that used to be available??? The engines didn't last very long because they weren't designed for the performance that the drivers were trying to get out of them. Running a stock duke at more than 5k repeatedly or sustained is asking for trouble.

I pulled a perfectly good vortec 350 out of my replica and went with an ls4. I would sell the entire package for $1500 or $1000 less the engine and transaxle so that you could save shipping. I've heard that the 350 adds 150 lbs. That is the only downside that I know of. I got 22 mpg on a cross country drive.

ok well im going the 250 way i got the engine ready i just need the parts from archie but his kits are sooooooooooooo expensive!!

quote Originally posted by KurtAKX: If I can show a dyno slip, can I have ten dollars from every person on this forum who (ignorantly, without any firsthand experience) claims that the Duke cannot make stock 2.8 power, or will immediately explode if set up to make more power than a 2.8? Terms of the deal: No, none, zero Superduty parts used. $10 from every 2.5 trash-talking member on PFF. Here's my build: http://s892.photobucket.com...20Rebuild/?start=all Just to provide fair warning...it needed a 454 TBI injector dropped into the pod to deliver sufficient fuel. How many takers?

To do all that work and spend all that money just to make 140hp, that has questionable reliability, when you simply could have purchased a 2.8, 3.1, or 3.4. Those are good engines to run some boost on, and make for a quick Fiero.

Not trying to be a jerk but what was the point of a turboing a iron duke?

It's not turbocharged.
It's reliability is not questionable.

It is set up to take my Superduty head, I just figured I'd see what I could get with a stock head first.
I did it because I wanted to.
I did it because it seemed like an interesting challenge...I can't make power with this just duplicating what I read in a magazine or on a forum. I had to use my brain a little bit.

Also, there's the fact that any Fiero with a V6 in any form of motorsport gets an extreme biotchslap in terms of the way its classified...

See that V6 Fiero listing classified HIGHER than a WS6 4th gen F-body?

It IS pissing money away pointlessly, just like putting a supercharger on a 2.8 is.


The real reason I did it was because I simply couldn't get enough of my favorite phrase, which goes something like this:
"u'r a ideot why didn u jist put a v6 in there?"

[This message has been edited by KurtAKX (edited 01-17-2011).]

quote Originally posted by KurtAKX: If I can show a dyno slip, can I have ten dollars from every person on this forum who (ignorantly, without any firsthand experience) claims that the Duke cannot make stock 2.8 power, or will immediately explode if set up to make more power than a 2.8? Terms of the deal: No, none, zero Superduty parts used. $10 from every 2.5 trash-talking member on PFF. Here's my build: http://s892.photobucket.com...20Rebuild/?start=all Just to provide fair warning...it needed a 454 TBI injector dropped into the pod to deliver sufficient fuel. How many takers?

Those injectors at 100% duty cycle can only feed 300 HP at 12.5:1 A/F , and the 454SS used 2, you you made 150.
If you happened across one of the stronger stock duke blocks, then I can see it taking that.
Dukes aren't happy above 5000 rpm, so mild boost is safer. Stock was 90 HP, so to make 150, takes about 9 psi in the intake manifold.
Stock parts should survive that if you keep it out of ANY detonation.
But for perspective, the weakest stock 350 ever was the '75 LM1. 155 HP at 3800 rpm.
Cheap speed king of all time remains the 350 Chevy. The L67 is in second place, and the LQ4 is in third.

quote Originally posted by Isolde: Those injectors at 100% duty cycle can only feed 300 HP at 12.5:1 A/F , and the 454SS used 2, you you made 150.

...at stock fuel pressure. I have an AFPR and a MPFI pump in the tank.

quote Originally posted by Isolde: If you happened across one of the stronger stock duke blocks, then I can see it taking that.

There are no "stronger" stock duke blocks. There are "T" blocks and "L" blocks, and they're both the same with the exception that "L" blocks don't have the provision for a side-mount water pump (and a couple other very minor differences)

quote Originally posted by Isolde: Dukes aren't happy above 5000 rpm, so mild boost is safer.

The stock cam, valvesprings, and rods are not happy above 5000 RPM. Fortunately those things are all easily remedied.
A set of later model 2.5 rods (the thick beam ones) with $40 worth of ARP rod bolts, a set of 943 "Z28" or Comp 981 valve springs, and a bigger cam, and its no longer a total tractor motor.

quote Originally posted by Isolde: Stock was 90 HP, so to make 150, takes about 9 psi in the intake manifold. Stock parts should survive that if you keep it out of ANY detonation.

Um, stock was 90hp with a VE in the mid-60s. If you were to install a better intake, cam, and do head work, you will exceed that level of VE. It takes 9psi to make 150 with a mid-60s VE. I am achieving that ouput without a turbo by increases in efficiency.

quote Originally posted by Isolde: But for perspective, the weakest stock 350 ever was the '75 LM1. 155 HP at 3800 rpm. Cheap speed king of all time remains the 350 Chevy. The L67 is in second place, and the LQ4 is in third.

I didn't read anywhere in punkguy0017's thread where he said cheapest was the primary consideration.

Well cheapest way to go is 350 carb engine is outta a 1978 camaro z28 everything in it is new i rebuilt it myself