Full stack intercooler IC with 3800- do I have to chop the trunklid (Page 1/4)
cam-a-lot JAN 29, 07:36 AM
There is a post on 3800 FB group regarding whether it is possible to run a 3800 SC motor with full stack IC without having to chop into the trunk lid

I did purchase a set of custom brackets and mounts for this specific reason in Michigan last year and hoping to do the install this year. Hopefully it works without the oil pan being far too low or axle angles being incorrect.

Has anyone here actually seen proof (pictures, video, or in person) that what I am asking for, and purchased, is possible in real life? Would really like confirmation before pulling my motor just to find out that the oil pan is lower than the cradle... or that I have to notch the trunk lid- in which case I may as well not use these mounts and brackets

Would appreciate some input- just looking for some reassurance before I bother to pull the motor and trans..

I have an F23 and Series III/ Gen V that would be going into the car. Full stack ZZP IC.

I also know a couple of people interested in doing the same thing and ready to buy mounts and brackets, but I have zero actual proof that it will work, and don't want to find out after pulling everything that I am wrong.. My current swap uses the old Purple Reign mount , but after putting in the F23, I could no longer use stock length axles. This is also another reason I want to change my mounts and brackets so that I can use stock length axles again, easier to source if I break them again, than having to get axle length modified.
fieroguru JAN 29, 06:56 PM
Measure the current clearance from the supercharger to the bottom of the decklid support.
Measure the bottom of the oil pan to the bottom of the cradle.
Add the two together. This is your available clearance.

Measure the height of the full stack.

If you are not running an intercooler currently: Available clearance - height of full stack = X.X
If you are running a short intercooler currently: Available clearance - (height of full stack - height of short stack) = X.X

If the number is positive, then it can be done with custom mounts and possible clearance work to the driver side rail on the cradle.
If it is negative, then you have more work. You should not mount the oil pan lower than the cradle, but you can lower the cradle crossmember, then lower the engine further, but this will likely require more clearance work to the driver side cradle rail.

There isn't enough room in the engine bay to move things to the point of axle angles becoming an issue. Just very they are bind free in the full range of motion, then you are good.

[This message has been edited by fieroguru (edited 01-29-2025).]

cam-a-lot FEB 01, 06:27 PM
Thanks Paul

I did buy customized brackets and mounts , and asked for photos prior to pickup to see how it all fit together. But I received zero photos... Oil pan depth.. Axle angle, etc. Hopefully I didn't male a mistake just trusting a verbal promise that it will work. Time will tell!

[This message has been edited by cam-a-lot (edited 02-01-2025).]

Rare87GT FEB 03, 10:32 AM
Who did you buy the mounts from? I'm guessing Brian Welch?

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88 Formula - 3800SC/4t65eHD
88 Coupe - 3800SC/4t65eHD
GBCT - 3800SC/F23

cam-a-lot FEB 03, 11:18 AM
Correct. They look very well made. I just don't want to put all this work into putting a new motor and trans into the car with different axles than what I currently have , unless I am sure that it will work. This is the whole reason I asked for multiple pictures, but unfortunately did not receive any. I supplied an 88 engine cradle and F23 trans for the brackets and mounts to get made.

I was hoping there is someone on here who has installed them and can confirm that stock axles work fine with this setup and F23, axle angle, and that the oil pan is not sitting dangerously low. I do have a working and running engine and F23 in my car now, with my trunk lid chopped up to allow for full stack IC. I have a nice new trunklid available that I want to replace it with. But again, this is a ton of work, and unless I am 100% sure that it all fits, it is a big risk to remove my existing setup.

Thanks
Rare87GT FEB 03, 01:52 PM

quote
Originally posted by cam-a-lot:

Correct. They look very well made. I just don't want to put all this work into putting a new motor and trans into the car with different axles than what I currently have , unless I am sure that it will work. This is the whole reason I asked for multiple pictures, but unfortunately did not receive any. I supplied an 88 engine cradle and F23 trans for the brackets and mounts to get made.

I was hoping there is someone on here who has installed them and can confirm that stock axles work fine with this setup and F23, axle angle, and that the oil pan is not sitting dangerously low. I do have a working and running engine and F23 in my car now, with my trunk lid chopped up to allow for full stack IC. I have a nice new trunklid available that I want to replace it with. But again, this is a ton of work, and unless I am 100% sure that it all fits, it is a big risk to remove my existing setup.

Thanks



Yeah I am not sure why he has not supplied pictures yet. The trunk was chopped on the Choptop to make work. But in my eyes, that is the way to go and not worry about anything sitting low. Plus Fierorog mounts are the standard usually. Maybe he will chime in and show us. But with how low my cars are, I wouldn't want the oil pan any lower than it is now as is. Just my opinion though.

[This message has been edited by Rare87GT (edited 02-03-2025).]

Dennis LaGrua FEB 03, 04:35 PM
Did the measurement in the past before buying the intercooler for my 3800SC swap. The short stack easily fit, the full stack would not have cleared the trunk lid unless the powertrain was lowered about 1". This was for an 87GT with WCF engine and trans mounts, With different mounts and a notchback body style the result may be different.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Rare87GT FEB 04, 09:31 AM

quote
Originally posted by Dennis LaGrua:

Did the measurement in the past before buying the intercooler for my 3800SC swap. The short stack easily fit, the full stack would not have cleared the trunk lid unless the powertrain was lowered about 1". This was for an 87GT with WCF engine and trans mounts, With different mounts and a notchback body style the result may be different.





The decklid has to be notched regardless. My only take on this is if Brian Welch can make it clear and not have to notch with a full stack then why isn't he producing mounts for that option? I'm not taking anything away from him as he is a good guy and OG Fiero owner, but on the other side it seems almost like no one knows about this. I hope he can show pics and how clearances are. No one really wants to notch a decklid especially a custom one, but with limited options it is kind of the norm.
cam-a-lot FEB 04, 06:09 PM
Agreed. This is the one and only reason I went all the way to middle of Michigan.. dropped off a cradle and F23. paid full asking price. I was told over and over and over again that this is possible, and that pictres are coming

Needless to say, I received zero pictures, so now I have to make tough decision as to whether or not I should bother to use the brackets and mounts I paid for, and drove a very long distance to drop off and pick up. Very frustrating, to say the least

thanks for your feedback
fieroguru FEB 04, 09:19 PM
While I certainly don't have all the details, here are my thoughts, for what its worth...

Suppling the cradle and F23 for these mounts, likely indicates you received the first set of this particular design.

Since you didn't get the pictures requested, there likely is no one who could give you 100% certainty on fitment. You may not like it, but this could very well be reality.

Last night I refreshed my memory of the build thread for your car... I think you already have all the engine, supercharger and full stack parts installed, with the decklid notched. If this is the case, then in less than an hour of work you should be able to figure out how low the drivetrain needs to go.

Measure how much past the bottom of the decklid the parts are protruding and which side is the critical interference.
Measure the current crankshaft centerline to the bottom of the cradle.

Those two measurements will allow you to know "how low you have to go"

For reference:
Stock 88 with 2.8/getrag should be around 8 13/16".
I previously reworked a SBC/F23 swap, lowering its installed height about 1 3/8" and ended up with an installed height of 8 1/8", with it shifted to the driver side about 3/4".

If your drivetrain needs to go lower than 8 1/8", things will get very complicated.

If you get past this point, I can likely walk you through how to determine if the mounts will get you to the desired drop.

[This message has been edited by fieroguru (edited 02-04-2025).]