I wonder if the dinky little Garrett GT15 would be a good match for a super low boost engine. It's capable of 200hp, but it's positively tiny so it could be nice to provide "invisible-feeling" low boost to an engine. 3-6 psi and no intercooler could add some grunt and make up for some breathing inadequacies with pretty much no downside.

[This message has been edited by thesameguy (edited 02-26-2015).]

Aluminum flywheel for the Duke
http://www.lmperformance.com/663702

quote Originally posted by E.Furgal: I've looked around my area for the last 2 years.. short of sitting in from of a yard hoping a wrecked 3800s/c was rolling in and offer more than the scrap price..

Sucks to be you! You can't throw a rock without hitting a 3800 for sale around here...

http://sacramento.craigslis.../cto/4908821511.html

quote Originally posted by fierosound: Aluminum flywheel for the Duke http://www.lmperformance.com/663702

How much does the stock flywheel weigh?

quote I wonder if the dinky little Garrett GT15 would be a good match for a super low boost engine. It's capable of 200hp, but it's positively tiny so it could be nice to provide "invisible-feeling" low boost to an engine. 3-6 psi and no intercooler could add some grunt and make up for some breathing inadequacies with pretty much no downside.

That would be a good choice, you want that boost at low rpm since the duke is tapped out at 4500-5000rpm.

Any input on the s10 2.5L in a fiero?

I wonder if an ECM from a 1993 S-10 would benefit he duke?

I'm pretty sure the issue you will run into first is that the crank is absolutely worthless. It's single counter weighted, and cast so thin and light, it really doesn't stand much of a chance for performance. There are some mercruiser cranks that will fit with modifications to the rear flange area and are really strong, they also increase displacement. Then, since it's a 4" bore engine, cheap forged parts can come from anywhere. Yes the deck of the block is thin, the cam only has 3 support journals, and the stock heads don't know how flow works, but boost can fix one of those issues. I think 200 hp on boost is attainable with the right bottom end mods. But... It won't be cheap for the most part, and it still won't be all that impressive performance wise. It would be unique though!

I've got my 85 duke to be peppy and fun to drive for not much money, here's what I've done:

-Removed and cleaned the throttle body.

-Removed the baffle from the throttle body.

-Cat delete

-Egr delete

-Accel coil and wires

-180 degree thermostat and lower temp fan switch from Rodney.

-removed cap from fuel pressure regulator and turned up fuel pressure.

-Halo spark plugs.

-advanced timing a few degrees.

-195/75-14 tires on stock wheels for less weight

-removed spare for less weight.

quote I'm pretty sure the issue you will run into first is that the crank is absolutely worthless. It's single counter weighted, and cast so thin and light, it really doesn't stand much of a chance for performance. There are some mercruiser cranks that will fit with modifications to the rear flange area and are really strong, they also increase displacement. Then, since it's a 4" bore engine, cheap forged parts can come from anywhere. Yes the deck of the block is thin, the cam only has 3 support journals, and the stock heads don't know how flow works, but boost can fix one of those issues. I think 200 hp on boost is attainable with the right bottom end mods. But... It won't be cheap for the most part, and it still won't be all that impressive performance wise. It would be unique though!

I understand that the motor is full of week points, the cast connecting rods, cast crankshaft and thin block... My goal was to get around 120hp on motor which should be fine with those parts. But putting a small T15 turbo with 5-6 psi boost would be fun and responsive.

Any updates?

Here a 3800sc or what ever engine can be had for for $490 out the door with everything, engine trans, all hang ons, ECM, everything.
Hell we had a 3800sc/trans at the shop for $1000 complete for like 9 years and no one wanted it, for the first few years it was even cheaper.

But to get back to the thread as Fierobessed said the crank is just weak, we droped one to watch it break, now you being in the boat business, go for the 3.0L mercrusier crank, get the later year one, I forget years, as the later year can be machined DOWN to fit, where the early years can't be machined UP, IE you have to fill the holes with bolts cut them off flat, have it lathed down and use a repair sleave to get a nice new surface. HUGE differance in cranks compared to the stock duke, that is the weak point, the next point hurting higher rpms is the coil, get good low ohm wires and it will rev higher with more power in the upper rpms.
We have test fitted a 3.0l mercruiser crank in a Fiero duke block, fits and spins great, you get 2 counter weights per cyl, instead of 1 per 2 cyls.
To build a "big bad duke" you need/want the murcruiser crank.

and saying that you couldn't get over 100 hp on the stock heads, the 87-88 dukes had 98HP so 2hp is not that hard to get.
If you want a ton of power I would say go different engine swap, but I love to see a duke pushed as everyone says, "do something different" so it makes it all the more fun. and the only reason I see to do it, I always wanted to do a duke all the way, and boost the hell out of one, just to do it and cheap parts.
You have the perfect place to start dealing with boats, but look at the 3.0L not the 2.5L.
I wish you luck and I hope you blow everyones minds on what a duke can do.

------------------
"DRIVE IT LIKE A FIERO"
'84 Fiero, engine to be determined '87 Duke (Sold)
'87 Quad 4 H.O.
'87Blue GT 3.4L Swap Completed!!!!!!!! Boosted!!!!!!!
^^^^ Now in the Construction Zone^^^^
Las Vegas Fiero Club Parts/Sales/Service/Club
Fiero Road Club Of Northern Nevada

any update on this project?

Check out my duke build, and the head I used.
The car in action...

[This message has been edited by TopNotch (edited 04-11-2015).]