Build update - 4T80 3800 Turbo (Page 7/10)
LFiero67 APR 16, 07:51 PM
Insured and registered car for the first time since 2016 this past weekend. I’ve put about 125km on it, running the 3800 turbo and 4T80 with the Holley Terminator X. Just idle and part throttle tuning right now with a 4lb spring in wastegate. Runs extremely well, shifts through all 4 gears and applies the torque converter clutch. I will try and upload some video the next time I have it out.

Super happy with the result and surprised a lot of locals.

------------------
10.007 @ 135.54MPH. <-- Video
Best 60' 1.42
Best mph 138.82
Billet 6262 Precision turbo, PT1001 intercooler, ST1 cam, 140lb springs, comp pushrods, HV3, stock L32 bottom end and heads.

Old M90 XP Cam time -
11.425 @115.60
1.543 60'

Trinten APR 16, 08:33 PM
That's awesome news! Congratulations!

I can't wait to see the numbers you put down with it at the track. Hopefully I'll be able to see it in person sometime. Maybe at the 45th Fiero Anniversary!
LFiero67 APR 16, 08:39 PM
Not sure I’ll take it back to the track. It’s a lot of stuff to buy/update to make it legal for 10.0 again. I’ll run some airport 1/8 mile events, the local 100’ race and enjoy it on the street. Unless I think it is going to run a 9, I don’t see going back to track. With the extra 150lbs I’ve added, I’m not sure a 9 is possible.
LFiero67 SEP 07, 10:12 PM
Today my son and I took the car for an excursion. Street tires installed and headed 85km (50 miles) to a no-prep event at a local airport.

Wife and daughter brought the drag radials and supplies out in the truck and helped run the car for the day.

Surface was less than ideal(see pic) but still had a pile of fun. Made 4 passes starting with street boost and turning it up from there. 60’ times were weak as I could only launch on 1-2 psi, and then let the turbo come in from there. I tried to launch on 2 step one pass and that resulted in lots of tire smoke and my slowest pass of the day.

Run 1 - 15 psi (how I drive on street) 2psi launch, 15psi at 1.56 seconds. 1.90 60’ and 7.46 @96.86 mph 1/8th.

Last pass (video)
~23psi (haven’t pulled log yet) don’t think I had any boost at launch.
1.93 60’ 7.28 @ 102.81 mph 1/8th.

For reference on a prepped track at lighter weight with old trans setup, I ran 1.4x 60’ times and 6.3x @ 108-110mph in the 1/8th.

Satisfied with the cars performance, we bolted on the street tires again and took the longer route home 95km (59miles).

Engine chugged along at 1950rpm at 74mph. No issues with the car all day, super happy with the results and reliability.

Ugly street tire setup:


Kids for pit crew:


Video of best run:
7.28 @ 102.81 on a 1.93 60’

Back home with a healthy layer of dust and bugs.




------------------
10.007 @ 135.54MPH. <-- Video
Best 60' 1.42
Best mph 138.82
Billet 6262 Precision turbo, PT1001 intercooler, ST1 cam, 140lb springs, comp pushrods, HV3, stock L32 bottom end and heads.

Old M90 XP Cam time -
11.425 @115.60
1.543 60'

[This message has been edited by LFiero67 (edited 09-07-2024).]

LFiero67 SEP 23, 08:41 PM
This weekend we took the car to Medicine Hat to participate in Southern Alberta’s Fastest Streetcar Shootout. This was the first time running on a prepped surface since September 2016.

Friday was rained out, but Saturday turned out to be a beautiful day. Drove the ~30 mile cruise with my son with only minor directional issues. At the checkpoint drew first round, a 2023 Dodge Demon, that turned out to be a Demon 170(8 second 1/4 capable factory). As the shootout is only 1/8th mile I was hoping to be close.

First pass car hooked, lifted front tires and then spun, handing the win to the other lane.

Adjusted the boost ramp, and added some launch retard which resulted in a 1.64 60’ and 6.628 @ 107.64.

https://youtu.be/MvgRRTc_Y-8?si=FbdZDLEbufqxrL7e

Put a bit more power back in the launch and lined up again, resulting in a 1.57 60’ and 6.59 @ 109.27.

https://youtu.be/4CyIJ6bKmEk?si=3habXK55_qxRngiy

Put some more power back in which resulted in another loss of traction and 7.16 @ 106.84 on a 1.75 60’





Overall happy with the results, drove into the trailer with no failures all weekend. Ran close to my best 1/8 mile MPH even though the car is about 200lbs heavier than last time out. With the launch figured out, if I can get it back into the 1.4 60’ range, it should run a high 9 as is.

I believe I am at the limit of this turbo and have definitely seen that the EBay intercooler is no where near as efficient as my old precision core.

Over winter I may look at upgrading the turbo and intercooler and try and finally get this thing into the 9’s, but for now very happy. I have driven and tuned since April without a major issue. The 4T80 /axle combo is taking the power without a hiccup so far. Terminator X Max has allowed me to run the combo much safer and with more control. It seems to be making more power with the coil per cylinder, proper fueling and timing control.

[This message has been edited by LFiero67 (edited 09-23-2024).]

pmbrunelle SEP 23, 09:31 PM

quote
Originally posted by LFiero67:
Adjusted the boost ramp



Is that in terms of time since launch, vehicle speed, engine RPM, something else?
LFiero67 SEP 23, 09:53 PM
In this case I made it stay on launch boost (11psi) for 0.55 seconds before the ramp to target boost began. Also pulled 15 degrees of ignition advance out for 0.5 seconds and then ramped that in over 1.5 seconds.
cartercarbaficionado SEP 24, 03:34 AM

quote
Originally posted by LFiero67:

Haven’t shared any pictures of the car since I started wrapping it last fall. Now that it has been seen in public, the cats out of the bag. Huge amount of work has gone into bringing this back to the street. It has been surreal driving it again after so long.







that's a pretty gt. I'm definitely a pop up guy but your mods play into each other nicely
Trinten NOV 04, 06:56 PM
Awesome stuff!

A few questions - your shifter, was it the stock Fiero automatic shifter assembly (excluding the knob with the two-step button mod)?
If it was, does it "line up" correctly with the stock Fiero gear indicator on the console surround (that is, do the detents in the 4T80 have different spacing that keeps the indicator from being in the right spot)?

We're getting closer to sorting things out with my 4T80 transmission issue. Line pressure is behaving correctly, shift points are good, now we're trying to figure out how/why TCC lockup is kicking on as soon as it shifts into 3rd gear - even when we disconnected BOTH the solenoid wires for the TCC lockup.

[This message has been edited by Trinten (edited 11-04-2024).]

LFiero67 NOV 04, 07:12 PM
Car was originally a 4 speed, so I don’t have the automatic gear indicator. I am using a stock Fiero shifter and cable, I have a offset interface between the stock 4t80 arm and the Fiero cable that I was able to adjust to get the shifter stops to line up with the detents in the transmission, and even first gear pulls in. I welded a mount for the cable to attach to the trans to work with all this.

In theory, since the trans detents line up with my shifter stops, it should work with the stock shifter surround, other than 1st gear, and 2nd being at 1, 3rd being at 2.



[This message has been edited by LFiero67 (edited 11-04-2024).]