Building the World's Fastest Duke!!! (Page 1/2)
Brivander DEC 07, 11:24 AM
Ok, Not even close, but got your attention

I'm not trying to make a rocket here, but I just want to make sure I am doing everything to get back to the stock power or slightly more.

Done So far:
1) Checked timing, ~7degrees so I bumped to 12degrees and am running premium. No detonation so far and a noticeable difference. 1984 - so standard distributor.
2) New Air Filter (matching a K&N I assume won't help unless the exhaust is improved).
3) Fresh Oil (VR1 Synthetic)
4) Replaced the O2 sensor which had an error code (BIG difference, especially in overall driveability).
5) Yanked the A/C belt since I don't even know if it works yet, I'll find out next summer (Michigan Winters....)

I am NOT trying to make a rocket here, but getting 10+hp would make a big difference in something that starts around 90!!!!. The exhaust is original, so I'm thinking of replacing the CAT anyhow, recommendations on a high flow cat? I don't want the smell or noise of a straight pipe.

Any other easy tricks? I'm not planning on tearing anything apart on the engine. Low and slow is fine with me, but low and less slow is better!!!

[This message has been edited by Brivander (edited 12-07-2021).]

IMSA GT DEC 07, 01:19 PM
Sorry to change the subject but the "Michigan winters" comment made me wonder, have you checked the heater resistor for debris or a mouse nest before using the heater?
Brivander DEC 07, 04:03 PM

quote
Originally posted by IMSA GT:

Sorry to change the subject but the "Michigan winters" comment made me wonder, have you checked the heater resistor for debris or a mouse nest before using the heater?



Yup, I went over this car top to bottom before I bought it. The condition was incredible. It was in a heated garage since the late 80's.

I actually found out some history on the car. I'll start another thread on it, but the second owner had the car from 1986 until he passed away in 2020. The owner before me bought it for one of his grandchildren from the estate and the parents (his daughter) said no. I got the car from him, he never even titled the car. On paper I am the third owner, but in reality I'm technically the 4th.
zkhennings DEC 07, 04:23 PM
Holley Throttle body with injector (which is similar injector to the injector in the crossfire style V8s) and a header and a cam. My friend's dad has a sweet duke in his, he has all the Herb Adams suspension bits and Koni shocks, delrin bushings, and he has a duke that has a cam, holley intake and throttle body, and a header on it, and he did something to the crank to allow it to rev to like 6500 rpms I forget if it was simply a different harmonic balancer or what. I will ask him next time I see him. He did all the mods back in 1987 to his 84' and it still holds up and drives around today probably makes around 20-30hp over stock but it is very noticeable, sounds really good too. His Fiero is the reason I ended up with one.
Brivander DEC 07, 06:08 PM

quote
Originally posted by zkhennings:

Holley Throttle body with injector (which is similar injector to the injector in the crossfire style V8s) and a header and a cam. My friend's dad has a sweet duke in his, he has all the Herb Adams suspension bits and Koni shocks, delrin bushings, and he has a duke that has a cam, holley intake and throttle body, and a header on it, and he did something to the crank to allow it to rev to like 6500 rpms I forget if it was simply a different harmonic balancer or what. I will ask him next time I see him. He did all the mods back in 1987 to his 84' and it still holds up and drives around today probably makes around 20-30hp over stock but it is very noticeable, sounds really good too. His Fiero is the reason I ended up with one.



The Holley Throttle Body / Intake is one thing I would do, but they are next to impossible to find. They stopped making them YEARS ago. It's a bummer....

[This message has been edited by Brivander (edited 12-07-2021).]

theogre DEC 07, 06:35 PM
put AC Belt back.
Even not working belt protect pulleys not getting rust.
Rusted pulley is hard to impossible to cleanup after. Road salt will attack belt surface and make more problems then 30 years of wear.

------------------
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.
(Jurassic Park)

The Ogre's Fiero Cave

Steel DEC 07, 09:05 PM
No leaks switching to synthetic?
Brivander DEC 07, 09:48 PM

quote
Originally posted by theogre:

put AC Belt back.
Even not working belt protect pulleys not getting rust.
Rusted pulley is hard to impossible to cleanup after. Road salt will attack belt surface and make more problems then 30 years of wear.




This car has never, and will never see salt! It will only get brief drives for testing over the winter, and when there is no salt on the road...like after rain etc.

That however, is a VERY good point that I hadn't thought of.

[This message has been edited by Brivander (edited 12-07-2021).]

Brivander DEC 07, 09:50 PM

quote
Originally posted by Steel:

No leaks switching to synthetic?



I've switched to synthetic in every car that's older I've ever owned. Never an issue. But this car has been running synthetic for years. Mostly changed as I don't know the age....

If it does leak, it should be addressed anyhow, that's how I see it.

[This message has been edited by Brivander (edited 12-07-2021).]

Patrick DEC 08, 12:17 AM

quote
Originally posted by Brivander:

1) Checked timing, ~7degrees so I bumped to 12degrees and am running premium. No detonation so far and a noticeable difference. 1984 - so standard distributor.



IMO, you're throwing your money away running Premium gas on a duke. Premium gas is for engines with higher compression and/or are boosted. Yes, I understand you've advanced the ignition timing beyond factory specs. So have I on my '84, and I run it on Regular gas after timing it old school by "ear". That involves advancing the timing a bit, flooring it while doing 30 mph in 4th gear while going up a slight incline, and listening for a "rattle". Keep advancing the timing bit by bit until you eventually hear the "rattle"... then back it off a little. If you ever hear it "rattle" again, back it off some more. I've found by advancing the timing in this manner, the gas mileage and acceleration improve, but the idle quality may suffer... and so do the smog test readings, so be forewarned.