Trinten's SBC/F23 build - The work has begun! (Page 11/76)
fieroguru MAY 13, 06:14 PM
Those are some pretty good numbers! Dial in the A/F ratio to 13.0 : 1 and you might get real close to breaking 400 whp. With the stock wheels, that thing has to be scary on the street.

Do you know the camshaft and heads you are running?
Trinten MAY 13, 06:39 PM
Hey Guru!

Comp Cams 280 XFI HR13 with their lifters as well. Heads are AFR 195cc Eliminator heads.


Edit: Actually it's pretty well behaved on the street, just a tad louder than I'd like. Easing it into first from a dead stop without making a bunch of racket, or without the engine bogging/car jerking is tough. Outside of that, with the Yokohamas I have on there, it's been a great little street car. But then again, I try to limit my stupidity to the track.

[This message has been edited by Trinten (edited 05-13-2012).]

fieroguru MAY 13, 07:36 PM
That low rpm jerking is probably due to the lean A/F mixure or too much low rpm ignition advance for the camshaft. Tweak those two and you will greatly improve your drive-ability.

Have you put enough miles on it to know what kind of mpg it will get on the highway?
Trinten MAY 13, 07:56 PM
Yes! I've been driving it around for a while now. At one point I got about 21 MPG, however, that was mostly highway. After my friend Ted adjusted the spark timing on it and played with the carb some last weekend, I noticed that the MPG has fallen down to around 19 - again, mostly highway driving. By mostly highway, I am referring to trips of 90 miles or more, with only two-four miles of it being stop-and-go to get on, or off, the highways.

I just wish Ted had picked up on the A/F thing, but it's not like he has a whole lot of high end tools, we were working with just a vacuum gauge. lol
Will AUG 28, 08:09 PM
Progress on getting your tune dialed in?
Trinten AUG 28, 08:17 PM
Hey Will!

Yes! I'm sorry I forgot to update this thread (I've been keeping it updated on the ncfiero forum). Here's the consolidated posts from that:

This was posted there on August 11th:

Alright! Got to Pro Dyno about fifteen minutes early, Scott was running about 15 minutes behind. Dan pulled the Fiero up onto the dyno and got it all setup. All in all, we did about 3 "cruise runs" (going at a normal acceleration to 70 mph to watch A/F) and 6 pulls.

Air temp was about the same as it was last time I was there, but the humidity was double!

When Scott showed up, he had Dan run a pull first to get a baseline. I was shocked to see how much of a difference humidity can make - down 14 HP and Torque!



From here on out, Scott changed the springs, metering rods, adjusted the idle, and played with timing. After the A/F was pretty much nailed down he tried adjusting the timing, first pushing it up two degrees, then back two, to see if it liked it any better. The "blue line" pull in the upcoming scan is from the advanced timing - I wonder if the dip and odd behavior of the car is when the belt popped off.

That's right, the belt popped off. Thankfully didn't snap. Just popped off. Dan didn't notice it because he's staring out the driving side window watching the computer monitors during the run. We didn't notice till he backed the car off and we saw the belt laying there. So Scott was wondering if it would have done better with that little bit more timing (or just in general), since it would have full juice coming from the alternator to the ignition system, and not just from the battery. Despite this, the engine made a horsepower more and the same amount of torque - in other words, we picked up 15 HP and 14 torque from the baseline.

Regardless, he set the timing back to where it was to start with, and we did a final pull, from "the blue pull" as a guide I lost 10 HP and 7 torque, but no oddities with the engine.



I debated on asking Dan to put it back on there when I got the belt back on (he was nice enough to loan me a floor jack, stand, wrench, and pry bar), so Scott could bump the timing again, but he was already occupied with something in the build-side of his shop when I was finished.

Regardless, after Scott was done, it was back near what it put down under better conditions, and Dan agreed - "You put it up here at 70 degrees and 19% humidity, it'll be a huge difference."

So picked up roughly 10 HP and 10 ft/lbs torque, and might have better mileage now that the A/F is fixed. Along with the possibility of another 5 HP/TQ lurking in the timing. I doubt I'll have a chance to put it on a dyno again before the EFI, but if I do, I'll bump the timing and see what it does.

If those gains translate directly (which I don't know if it works that way), that puts my car at around 381 HP and 391 ft/lbs torque in 28% humidity (versus the 48%-56% today).

Now just to wait and see how my gas mileage does, how it does at the track in a few weeks, and what it puts down once the EFI is on there!

*end of that post*

I've had it to the track since then, slips up in the 1/4 mile thread. My gas mileage dropped about 1 mpg on the highway. Though that was driving up into West Viriginia, so I'm not sure what kind of impact the mountains would have had on my MPG, compared to the (relatively) flat highways I normally drive on.

Also busted a tripod at the track (hope that's all it is, troubleshot it on the phone with CowsPatoot), so looking into doing the tripod swap from the Berettas in the short term, see how they hold up. If I get more failures there, I'll see if the DSS axles have upgraded tripods too, or if their strength rating is just for the actual axle.

Thinking about trying to figure out how to do a "Safety loop" for the axles, near the transmission, so if it breaks in a really bad spot, it won't whip around and smash my transmission.
Trinten JUL 21, 05:05 PM
So, no updates because nothing much has been going on! (Except I need to redo the pictures, since webshots closed their doors, and all the picture links are broken)

Between work, family and the next step of my car requiring someone with far better skills than I, just not much has happened.

But starting this Wednesday, that will change!

Someone with commendable skills (and equipment) at his disposal, agreed to do my EFI swap, get my A/C working, redo my exhaust a bit (to try to make it quieter without constriction, and ceramic coat it), dyno tune, and get it setup with a freaking sweet Serpentine belt setup, with an idler pulley! So no more squeaky belt! No more belts snapping (as often)! Better arrangement of my coolant pipes!

Plus he's going to put my stock decklid on there, which is not in as nice condition as my current one (current one has a relatively new coat of paint), but if the scoop isn't functional/necessary, I don't see a reason to keep it on.

He knows I pay for quality work, and that I wouldn't haggle with him over the cost, and I think that's why he took the job.

He said he was also going to clean up the engine bay, move the C500 connector, and remotely setup my water pump.

I'm not saying who it is yet, because I don't know if he wants to publicize that he's doing this work for me just yet.

Oh! He's also going to be putting in my rockers and the stock-height valve covers - when I bought my valvetrain setup, I didn't realize that everything was designed for 1.6 rockers, and I bought 1.5 rockers. There's some other stuff I've asked him about too, but I'm going to wait on posting the full list after it's all said and done.

Yes, I'm one of those guys that mostly "just write checks", but I always give credit where it's due, and would rather see it done with fantastic results the first time (and not have to worry about it breaking), getting that piece of mind, rather than the sense of accomplishment that comes with trying to do this stuff myself (most of which I couldn't, anyway... it would require a bunch of machining equipment).

fieroguru JUL 25, 07:56 PM
This thread needs some pictures!

As Trinten stated above, his SBC/F23 car is finally going to get some proper attention and love. His car showed up at the house today and kicked the LS4/F40 car out of the garage for a few months.


The car already has a pretty stout engine with the chassis dyno chart to prove it (371 whp), so its doesn't need much upgrading there (roller rockers and valve springs). I get the honor of performing the upgrade to fuel injection to this setup while refining the rest of the swap into something he can be proud to show off.

The fuel injection conversion will use a modified Holley Stealth Ram intake controlled via an LS1 ecm. Here is a teaser pic:


It will also have the mounting system reworked (engine isn't level), the coolant system revised, the accessory drive converted to serpentine, the exhaust reworked and the engine bay detailed in similar fashion as my LS4/F40 swap... Stay tuned.
Trinten JUL 25, 09:36 PM
Guru is crazy-efficient. That car was in his driveway around 4pm Eastern today (I know, I called CowsPatoot, who transported it on his trailer, a few minutes to 5pm, and he was saying they were just getting ready to leave after he zipped around in my car a bit chasing Guru's Fiero). So in three hours, he has:

Gone over my intake system.
Inspected my car.
Detailed some issues with it, sent me a VERY thorough PM about all of his findings and questions.
Drove it to use up some of the gas in the tank (I had a near full tank, but there's been so much rain in Charlotte for the last two months I haven't been able to drive it as much as I wanted)
Did his posts here with pictures. In less than 3 hours.

That's on par with L67 dropping the engine/cradle by himself in like, 90 minutes and sending me pictures of it, when he'd never really messed with a V8 Fiero before.

Thanks again to FieroGuru for taking this project on. I'm really looking forward to everything!!

[This message has been edited by Trinten (edited 07-25-2013).]

fieroguru JUL 27, 05:22 PM
Here are a few before pictures:



One of the more interesting aspects of this car is the electric water pump was bolted to the engine without cutting into the wheel well sheet metal. Instead to make the needed clearance they hammered the area outward for clearance. I hadn't ever seen one done this way and think this approach might be better than cutting the hole as it keeps the pump protected from wheel well debris. The pump will be remote mounted as part of the work.


Here is a teaser pic of what the engine swap will look like when done... HSR intake, upper plenum flipped, twin 58mm throttle body. The engine will be lowered as part of the rework to gain the needed clearance for this intake to clear the decklid. Disclaimer: the height of this particular HSR is 9", but a stock one is 10" tall. This intake was modified by gusshotrod to make it lower several years ago, and this modification is what allows it to have a chance of fitting w/o a decklid support notch.