The Silver Freak Project (Page 57/59)
La fiera APR 25, 07:47 PM
That looks great! You'll enjoy the engine sound at hi rpm with those ram pipes!
La fiera APR 27, 08:23 PM


Hey look what I found in my memorabilia! I think I can recognize that intake!
Blacktree APR 28, 07:23 PM
Here's another quick-n-dirty video. This one is cold start-up. Getting to the point where I could just turn the key and it goes *vroom* took some effort. But that's one of my pet peeves. I don't like to fiddle with the gas pedal or do any special procedure to start it up.



I think the cold idle needs just a little more tweaking, and then I can check that box.
La fiera APR 28, 09:05 PM
Sounds pretty good! What RPM does it idle? I don't have an IAC and mine starts cold a about 950RPM and when fully warm at about 1000-1100RPM. Since most of the time it'll be on the track I really don't need a good idle speed.
Blacktree APR 28, 10:05 PM
On cold startup, it sputters a bit then idles around 1100-1200 RPM. After it warms up, the idle is around 900-1000 RPM. Cars typically idle faster when cold, to help the engine warm up. So I tuned the idle to do that.

I'm using the open-loop idle mode, because the closed-loop idle doesn't work very well with the new setup. Whenever I enable closed-loop idle, the engine sputters and dies. That sucks, because the closed-loop idle allows me to tell it what RPM I want, and the ECM makes the necessary adjustments. Open-loop idle can't do that. So the RPM fluctuates a bit. You can hear that in the video.

The car is perfectly driveable. But the fluctuating idle annoys me. I guess you can't have everything, right?

PS -- I performed a compression check the other day, and all cylinders came in between 145-150 PSI. That roughly equates to 10:1 compression ratio, which was my goal for the build. I'm pretty happy with that.

[This message has been edited by Blacktree (edited 04-28-2018).]

La fiera APR 28, 11:26 PM
Great! One thing I learned was that idle is very responsive to timing. Look where the engine is at idle and make sure the timing is the same. Different timing equals hunting idle. With that bigger cam and more air volume at lower velocities you need higher timing at low to mid. At high rpm retard some and you'll have the best results.
Blacktree APR 29, 04:21 PM
Good news! I got closed-loop idle working. Now the ECM will automatically adjust to maintain a certain RPM.



I also adjusted the spark timing table, as Rei suggested. That helped, as well.

[This message has been edited by Blacktree (edited 04-29-2018).]

Blacktree MAY 03, 08:34 PM
The engine developed a slight miss recently. I noticed one of the coil packs had a crack in the housing. Plus the other two were pretty old. So I replaced all 3 with Delphi units. The two old ones can be used as spares.

Also, the big brown Fiero parts truck stopped by today:



Finally, the Freak is getting a proper racing harness. Yeah, I know... took long enough.
Blacktree MAY 07, 08:15 PM
The harness is installed.



The lap belt uses the stock mounting points. The bolt for the floor belt goes through the driver side frame rail. And the shoulder belts attach to the firewall, with load spreading plates. The shoulder belts can also be wrapped around a roll bar, if I install one in the future.

I took the photo below, just for kicks. But you can see that I lined up the mounting points with the holes in the seat.
Blacktree MAY 25, 12:52 PM
There's nothing exciting to report right now. I've been driving it around a bit, letting the autotune do its thing. Some of the results are surprising. For example, the VE table is in the triple-digits between 2000 and 5000 RPM (at WOT). I thought naturally aspirated engines didn't go above 100% VE? I should probably take a log of the injector duty cycle at WOT, to see if they're being overworked.

Anyway, I also had to renew the tags on my cars. The Fiero was eligible for an antique tag. So I got one.