Well yep, I went and did a bunch of engine mods to an 84 Duke. I am here to tell you I think it was worth it. Then again, I am new to doing engine work. Here's a list of what I did and my impressions.

Holley TBI
CompCam high lift camshaft and lifters
DIY gasket match porting from TBI to exhaust manifold
Glasspacks to replace catalytic converter and muffler both
MSD blaster coil
DIY engine overhaul per Haynes manual

My Impressions are: It is a lot more fun to drive. Has a lot more pickup. Sounds pretty good from an exhaust point of view. I am getting better than 9 seconds 0-60 times at the toll booths. Improvement in gas mileage to around 26 mpg mixed from 24ish. Has more torque in 2nd and 3rd than before with about the same for 1st and 4th which was pretty good already.

There are a few negatives. It seems just as noisey in the engine clatter department although I have not changed out the springs or pushrods yet. Idle seems a little sort of jumpy- very minor but before it was stone solid.

So, all you Dukesters...if these sorts of things are what your looking to do...they can work out. I dont have HP #s but the engine gets more midrange power which is a great improvement for performance. I have not noticed any drawbacks from these mods yet at all.

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

If I were to further work on the car It would be to quiet it down, and lighten it up. The Porsche 550 spyder was about 1000 lbs lighter with a similar engine @115 hp. I dont know any way to quiet the Duke yet. If anyone has suggestions I would like to hear them. For lightening seems like constructing an aluminum space frame and transfering parts would do it. Any thoughts? I think the perfect car would be be very much like a Fiero but with 150 HP and be less than 2000lbs. And be a convertable.....or T-tops. Sounds like I am thinking Ferrari right?

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

For anyone else - the Tech IV in the Olds Ciera had 110hp out of the box.
Not sure what the exact specs for this engine are.

1989-1992 Tech IV 2.5 L (151 in³) I4 110 hp (82 kW) and 135 lb·ft (183 N·m)
http://en.wikipedia.org/wik...mobile_Cutlass_Ciera

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My 3.4L S/C 87 GT
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quote Originally posted by fierosound: For anyone else - the Tech IV in the Olds Ciera had 110hp out of the box. Not sure what the exact specs for this engine are. 1989-1992 Tech IV 2.5 L (151 in³) I4 110 hp (82 kW) and 135 lb·ft (183 N·m) http://en.wikipedia.org/wik...mobile_Cutlass_Ciera

Interesting. I wonder if the ECM would have to be swapped with it.

I'll bet they tweaked the fabrication process by that time....a little

http://www.youtube.com/watch?v=MPgKgUXSXKI


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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

[This message has been edited by White 84 SE (edited 09-20-2009).]

New shortblocks http://oem-surplus.com/gmwp...hlight=pontiac+parts

quote Originally posted by fierosound: For anyone else - the Tech IV in the Olds Ciera had 110hp out of the box. Not sure what the exact specs for this engine are. 1989-1992 Tech IV 2.5 L (151 in³) I4 110 hp (82 kW) and 135 lb·ft (183 N·m) http://en.wikipedia.org/wik...mobile_Cutlass_Ciera

It has DIS and 700 TBI. Like 87-88 L4 Fiero. No ideal what else. Will not fit, IE drop it, 84-86 Fiero. May has be a different engine... Same as V6.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
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[This message has been edited by theogre (edited 09-20-2009).]

The 91-92 Vin R duke has 110 HP. It was used in, among other vehicles, Chevy Luminas. It has a timing chain instead of gears. Because it is a Vin R, it should fit in a Fiero easily, but is DIS, so re-wiring and a different ECM would be needed on 84-86.

[This message has been edited by TopNotch (edited 09-20-2009).]

quote Originally posted by TopNotch: The 91-92 Vin R duke has 110 HP. It was used in, among other vehicles, Chevy Luminas. It has a timing chain instead of gears. Because it is a Vin R, it should fit in a Fiero easily, but is DIS, so re-wiring and a different ECM would be needed on 84-86.

I am SURE my engine is getting over 110HP. That timing chain thing may quiet the engine a bit though....

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

quote Originally posted by TopNotch: The 91-92 Vin R duke has 110 HP. It was used in, among other vehicles, Chevy Luminas. It has a timing chain instead of gears. Because it is a Vin R, it should fit in a Fiero easily, but is DIS, so re-wiring and a different ECM would be needed on 84-86.

vin R cars had 110 hp? i had a 88 duke pontiac 6000. i always thought it was the 92 hp engine.

hiperformance offers some kind of Hi Performance 2.5L motor. You'd have to email an inquiry http://www.hiperformer.com/...s/pontiac-fiero.html

[This message has been edited by fierosound (edited 09-20-2009).]

Thanks Fierosound.... Ive already worked my engine and spent just a few hundred dollars doing all the work I have a "remanufactured" and hopped up little Duke. Still, there must be a lot of dudes with way more money than time and might go for such offerings.

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

quote Originally posted by White 84 SE: The Fieros were High Output, dont know what the 6000s were although they both were vin Rs. OOPS... I was confusing the V6s and the Dukes.... forget the above observation....

hahaha

quote Originally posted by americasfuture2k: hahaha

lol....well I mean...*

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

quote Originally posted by americasfuture2k: vin R cars had 110 hp? i had a 88 duke pontiac 6000. i always thought it was the 92 hp engine.

The 88 Vin R duke is rated at 98 HP. You need a 91-92 to get the 110 HP rating.
Edit: HP ratings of Vin R dukes (as used in Fieros)
84-86: 92 HP
87: 96 HP
88: 98 HP

[This message has been edited by TopNotch (edited 09-21-2009).]

Just an observation here. I've noticed that Fiero owners in general seem all about dropping different parts in thier cars. As if the cars were inherently crap. Not working on and improving them just replaceing parts. This must be a new school thing. To me it seems lame as far as being a car enthusiast. When I think about car enthusiasts my first idea is that here are dudes that really tweek thier cars to being fine tuned machines but it seems more about "whatyagot" "wheredyabuyit" "sweetdealdude!!!". It seems more about conspicuous consumption. Perhaps a tad better than just the new stickers. Perhaps I am just disappointed with consumer culture. Still, I am quite different than all that for one and I aint changing my position. I am sure not the only one.

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

I've got to agree with your statement !
Since we don't have such a big selection of available US motors over here (3800, Northstars etc...), we go for improving what we've allready got in the car.
If you do put something else in the engine bay, then try to explain to the local DRIRE inspector that you just swapped in a bigger 90° V6 in the place of your original 60° V6. He won't like it.
He will just ask for the homologation certificate from the car manufacturer. Oh! You don't have one ! You did the swap yourself ?
Well Sir, you car is now illegal for the open road. Kindly take it back on a trailer and leave it in the bottom of your garden, never to be driven again !!
Like I said, get the most out of what you have, and enjoy it.

quote Originally posted by White 84 SE: Well yep, I went and did a bunch of engine mods to an 84 Duke. I am here to tell you I think it was worth it. Then again, I am new to doing engine work. Here's a list of what I did and my impressions. Holley TBI CompCam high lift camshaft and lifters DIY gasket match porting from TBI to exhaust manifold Glasspacks to replace catalytic converter and muffler both MSD blaster coil DIY engine overhaul per Haynes manual My Impressions are: It is a lot more fun to drive. Has a lot more pickup. Sounds pretty good from an exhaust point of view. I am getting better than 9 seconds 0-60 times at the toll booths. Improvement in gas mileage to around 26 mpg mixed from 24ish. Has more torque in 2nd and 3rd than before with about the same for 1st and 4th which was pretty good already. There are a few negatives. It seems just as noisey in the engine clatter department although I have not changed out the springs or pushrods yet. Idle seems a little sort of jumpy- very minor but before it was stone solid. So, all you Dukesters...if these sorts of things are what your looking to do...they can work out. I dont have HP #s but the engine gets more midrange power which is a great improvement for performance. I have not noticed any drawbacks from these mods yet at all.

Hi there, I thought you went with the Fierostore performance cam? Is that the same cam as the Comp? BTW where did you find a keyway for that cam?

quote Originally posted by patch: Hi there, I thought you went with the Fierostore performance cam? Is that the same cam as the Comp? BTW where did you find a keyway for that cam?

Yes mine is the FieroStore one. The key was in there with the old cam. You do mean the the locking device on the cam to gear right?

What are the specs for your cam. Mine is a 272 degree cam. I hope to have the car on the road soon so I can document the performance even though the car will no longer be mine.

quote Originally posted by patch: Hi there, I thought you went with the Fierostore performance cam? Is that the same cam as the Comp? BTW where did you find a keyway for that cam?

By the way I've seen woodruff keys in the fastener isle at Lowes of all places. Dont know if they fit or anything else about them.

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

When I called comp cams about a turbo grind they gave me a custom grind number and said all I have to do is order it through my reseller (Fiero Store). Cost was the same as a full standard grind with lifters kit so I opted for the kit to save some $$. It would seem to follow you could custom order a wider LSA to better work with a supercharger.

quote Originally posted by Hudini: When I called comp cams about a turbo grind they gave me a custom grind number and said all I have to do is order it through my reseller (Fiero Store). Cost was the same as a full standard grind with lifters kit so I opted for the kit to save some $$. It would seem to follow you could custom order a wider LSA to better work with a supercharger.

Good tip thanks...uh wherdego?...ohthere...Hudini.


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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

[This message has been edited by White 84 SE (edited 09-22-2009).]