Real Fiero Tech

I didn't tune anything, I let the professional do it. I trust him to do it right, he tunes cars all day long and he has a reputation in the area for being very good at it.
I plan to pull the engine apart this weekend.

Hey guys, I haven't had much time to post or even read the forums lately. I'm really busy trying to ballance my time between my real job, side jobs, and keeping my girlfriend happy. I just wanted to give some info on this car. The trans is a 4T65E-hd. It was a new 'crate' trans from GM, not rebuilt ...

The green wire should be connected to the reverse light circuit. When +12v is applied to the green wire it disables the dimmer so that you can back up with full use of the mirror.

Jon

in torque management mode and starting from a stop in 2nd I did a N*/4T80E swap using the stock '93-95 PCM and stock PROMs. No traction control module or any other modules. The transmission operates normally, it does not start out in second gear. Though it may be operating in some mode of reduced p...

Since the Fiero uses a 4000 PPM signal to drive the speedometer, you'd have to use an IP divisor of 1

Yep, that's what I meant. Thank you for the correction.

The Fiero VSS is a magnetic unit that puts out 4000 PPM, sine wave on two wires. That sine wave goes directly to the speedometer. The speedometer has a built in buffer that divides the signal and outputs a rough square wave at 2000 PPM to feed the ECM and cruise control module. That output is on one...

I've used V-bands on the last two turbo cars I put together. The things are just so neat I use them for every joint. Headers to Y-pipe, Turbo to down pipe, and down pipe to muffler. If they weren't $50 apiece I'd use them on every car. Be careful about welding them. If you warp them they will leak. ...

Yes, here we go again..... I like them all (except for the 3.4). I documented the 4.9 because that's what I was into when I built the website, and because you can't find that info anywhere else on the web, at least not at that time. I'm not biased toward the 4.9, I may have been at one time, but not...

Will,
I have the super-deluxe OTC/SPX TimeSert kit to repair every bolt hole on a Northstar, '93-99 and '00-03. I may be convinced to loan the tools for a good cause.

I also have a TimeSert kit for just the head bolts, it's for sale if anyone is interested.

Will, I don't totally agree. What prevents it from pulling air into the system through the rear cap when it cools down? There should only be one venting cap on the system, the other end should be a sealed cap, just like a stock Fiero system. You could put a recovery tank at both ends, but then there...

I forgot to mention, I have never used a presurized expansion tank. I use the stock Fiero overflow system with a sealed filler neck at the engine.

Mine works fine with the stock V6 rad, but I wouldn't be surprised to see the coolant temp go out of control when I get it tuned properly. The other N* swap I did is also using a stock rad, and after getting all the air out it also works fine. The owner has reported some temperature spikes on the st...

I have used a resistor in the past, but I don't remember what value I settled on. I don't know what the current threshold is to excite the alternator, but it's pretty low. 220 ohms should get it going. Make sure it's a 1 watt resistor or higher if you want to keep the smoke inside. Or just use a bul...

He said given the freedom to do whatever, he would extrude hone the exhaust manifolds. I believe he said the exhaust crossover was decent enough stock, but obviously there's some reason he'd hone the manifolds over any other mods... I don't think he was talking about a Northstar. You can't extrude ...

I believe Bud Adelman, the proprietor of http://www.gr8grip.com/ has or can get oversized sleeves for the 4.x engines. Bud can bore your stock liners. He did a set for a guy I sold some Northstar pistons to (1mm over). I made a fixture to lathe bore them and it seems to do a pretty good job, but I ...

IMO, the dowel pin is absolutely necessary. The 3.4 uses conical locks and those fuckers hold tight long after the bolt is removed. Remove the bolt from a N* and the sprocket will fall to the ground if you're not careful. There's no sense making them adjustable since you can't access them with the e...

I have an Innovate LM-1 and LMA-2 aux input for datalogging 5 other sensors. $425, that's for the handheld WB controller/logger/readout and aux cable only, does not include the dashboard gauge. Do a little research and find out why Innovate wideband controllers are superior to AEM, PLX, FJO, etc. Th...

I have an EGT on my Northstar with the probe a few inches past the turbo. I've never really paid much attention to it but I know she gets up to 1200 or so when I step on the skinny pedal. There's too many more important things to be looking at unless you're logging data and analyzing it later. Get a...

TunerCat's CalData works very well for identifying bins/ECMs.

The shortstar has an 89.5mm bore 92mm stroke, northstar is 93mm bore 84mm stroke. it's not really just a northstar -2. Aurora 4.0 is 87mm/84mm. shortstar rods are 153.4mm, the V8s are 151mm. You can buy those Eagle H-beam northstar rods for $450. I'm thinking about getting a set, but not really sure...