Corvettes are RWD, and the motors are longitudinally mounted.
Fieros are Transversely mounted. You're gonna have to do a ton of custom fab and design, assuming the motor will even fit sideways in a Fiero and still leave room for an transmission, axles, and accessories.
It would probably be easier and smarter to stretch your Fiero so that you can mount the motor longitudinally near the back window and use a Porsche or Audi transmission. Either way, it would cost a lot.
The new LT1 has about the same dimensions as the LS(x) engine family, so I am sure someone will eventually put one in a Fiero. Its just a matter of waiting for the electronics to be figured out on how to run the engine in another chassis. I assume GM will make it available as a crate engine with standalone controller at some point in the future.
I believe that V8Archie would have the answer for you. He's done more SBC V8 and LS1,2,3 swaps than anyone. The engine should fit using his kit components but due to the length of the engine you cannot use a 4T65eHD transmission. Only the shorter LS4 engine can be made to fit with the high performance auto and it is a tight squeeze. The longitudinal swap would work but your choice of transmission is the very old and heavy TH325, or TH425 used on the FWD Olds Toronado.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, 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 "
Originally posted by Dennis LaGrua: The engine should fit using his kit components but due to the length of the engine you cannot use a 4T65eHD transmission. Only the shorter LS4 engine can be made to fit with the high performance auto and it is a tight squeeze.
The only parts shorter on the LS4 than the RWD LS(x) versions is the crankshaft and front accessory drive. The LS4 block is actually about 3/16" LONGER than the RWD versions due to changing to the GM Metric bellhousing.
If an Archie LS(x)/F40 fits with the transmission being 13 1/2" long and an adapter plate around 1 1/2" thick, then the 11" protrusion from the 4T65e-hd should be a non-issue - the auto setup is over 3" shorter even with the adapter plate included. Don Kraus ran a truck based LS(x) engine with a 4T65e-hd using the LS4 accessory drive... so they work and fit just fine.
The issue using the 4T65e-hd will be the electronics... the ECM that runs the Gen 5 LT1 probably will not run a 4T65e-hd, so you likely will have to run a stand alone controller if you want to use that transmission.
It should fit just fine. You should be able to use the LSx kit from V8Archie to mount one up. GMPP does not seem to have an E-ROD version of the Gen V engine yet though, so ordering an engine for a Corvette and swapping it in might be a bit difficult in terms of programming.
The only parts shorter on the LS4 than the RWD LS(x) versions is the crankshaft and front accessory drive. The LS4 block is actually about 3/16" LONGER than the RWD versions due to changing to the GM Metric bellhousing.
If an Archie LS(x)/F40 fits with the transmission being 13 1/2" long and an adapter plate around 1 1/2" thick, then the 11" protrusion from the 4T65e-hd should be a non-issue - the auto setup is over 3" shorter even with the adapter plate included. Don Kraus ran a truck based LS(x) engine with a 4T65e-hd using the LS4 accessory drive... so they work and fit just fine.
The issue using the 4T65e-hd will be the electronics... the ECM that runs the Gen 5 LT1 probably will not run a 4T65e-hd, so you likely will have to run a stand alone controller if you want to use that transmission.
If this is the case then why do we not then see LS2 and LS3 Fiero auto swaps??? The LS4 PCM should be able to run them with the 4T65eHD, right? There must be a reason why most of the auto swaps appear to based on the LS4. As for the new LT1, don't know much about it yet so we shall see!!! However, there has to be some limit on torque and power that the Fiero chassis can tolerate. We don't hear much about Don Kraus of late since he finished his LS7 swap. Something tells me that he didn't best his 3800 turbo times.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, 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 "
Originally posted by fieroguru: The only parts shorter on the LS4 than the RWD LS(x) versions is the crankshaft and front accessory drive. The LS4 block is actually about 3/16" LONGER than the RWD versions due to changing to the GM Metric bellhousing.
If an Archie LS(x)/F40 fits with the transmission being 13 1/2" long and an adapter plate around 1 1/2" thick, then the 11" protrusion from the 4T65e-hd should be a non-issue - the auto setup is over 3" shorter even with the adapter plate included. Don Kraus ran a truck based LS(x) engine with a 4T65e-hd using the LS4 accessory drive... so they work and fit just fine.
The issue using the 4T65e-hd will be the electronics... the ECM that runs the Gen 5 LT1 probably will not run a 4T65e-hd, so you likely will have to run a stand alone controller if you want to use that transmission.
It should be possible to use this transmission with a Gen V engine as well, as it requires a separate controller. If I understand correctly, all the electronics for the auto transmissions in the Gen V engine vehicles, are housed in the transmission itself. It might be possible to use a 6t75 without an external controller, with the new ECMs for the Gen V (or even with an E38 ECM for a Gen IV engine).
Originally posted by Dennis LaGrua: If this is the case then why do we not then see LS2 and LS3 Fiero auto swaps??? The LS4 PCM should be able to run them with the 4T65eHD, right? There must be a reason why most of the auto swaps appear to based on the LS4. As for the new LT1, don't know much about it yet so we shall see!!! However, there has to be some limit on torque and power that the Fiero chassis can tolerate. We don't hear much about Don Kraus of late since he finished his LS7 swap. Something tells me that he didn't best his 3800 turbo times.
As for why there are not more... The LS1/2/3/7 engine with 4T65e-hd requires a custom adapter plate and Fast Fieros was the only vendor to ever sell one (Don's car). Once he closed up shop, the adapter plate needed for the swap was not available. While Archie has been responsible for 95+% of the LS1, LS2, LS3 and LS7 swaps, he never developed the needed adapter plate to use the 4T65e-hd. For the other vendors wanting to get into the LS(x) swaps, but not wanting to develop an adapter kit, the LS4/4T65e-hd combo was the logical and economical choice. The DIY group also favors the LS4/4T65e-hd combo because it is a factory paired setup, doesn't require an adapter plate or other custom machined parts, and you can buy a complete dropout from $900+ depending on miles and luck (this last sentence sounds a lot like the 3800).
The lack of LS2/LS3 engines paired with the 4T65e-hd has nothing to do with length and a lot to do with lack of the needed adapter plate and cost of the swap. When Don did his swap, he could have done a LS2/LS3 swap with the 4T65e-hd, but he wanted more power and had his engine built based on the cast iron block and stroked to 427 CI (his is not an LS7). He was never able to do a full effort run with it due to health issues (so the car still has more in it), but it was still much quicker than his 3800 times. From the 1/4 list... Don Kraus: 10.519 @ 129.92mph (IMSA widebody kit / LS427 / 4T65E-HD) Don Kraus: 11.323 @ 116mph (Aldino kit / 3800SC-II / 4T65E, posi)
[This message has been edited by fieroguru (edited 09-28-2014).]
It should be possible to use this transmission with a Gen V engine as well, as it requires a separate controller. If I understand correctly, all the electronics for the auto transmissions in the Gen V engine vehicles, are housed in the transmission itself. It might be possible to use a 6t75 without an external controller, with the new ECMs for the Gen V (or even with an E38 ECM for a Gen IV engine).
Starting with the Gen 4 ecms, they no longer accept segment swaps and I expect the same will hold true for the Gen 5 ecms. This is why no one can get a factory V8 calibration to control the 6T75 even though the V6 ecm calibrations can. Back in the Gen 3 era, you could just do a transmission segment swap and run a 4T80 with an engine that never came with one... but that isn't possible with the Gen 4s and it will likely be true for the Gen 5s.
So to use the 6T75 (or future versions), you will almost certainly have to run a stand alone transmission controller. (unless you want to run the Ford version of the FWD 6 speed auto was offered with a V8 and try to adapt the Ford ECM to run an LS(x) engine....)
Originally posted by fieroguru: Starting with the Gen 4 ecms, they no longer accept segment swaps and I expect the same will hold true for the Gen 5 ecms. This is why no one can get a factory V8 calibration to control the 6T75 even though the V6 ecm calibrations can. Back in the Gen 3 era, you could just do a transmission segment swap and run a 4T80 with an engine that never came with one... but that isn't possible with the Gen 4s and it will likely be true for the Gen 5s.
I imagine this is a matter of programming, and that that portion of the programming is just not unlocked by most programmers?
Originally posted by fieroguru: The lack of LS2/LS3 engines paired with the 4T65e-hd has nothing to do with length and a lot to do with lack of the needed adapter plate and cost of the swap. When Don did his swap, he could have done a LS2/LS3 swap with the 4T65e-hd, but he wanted more power and had his engine built based on the cast iron block and stroked to 427 CI (his is not an LS7).
Indeed. The LS4 is a much cheaper and easier way to get an LSx+auto in a Fiero.
Don's engine is an aluminum block though. It's an L92 (2008 Escalade) block, built out to 427cid, and has the LS7 heads/intake IIRC. This is why people often confuse it with actually being an LS7.
Starting with the Gen 4 ecms, they no longer accept segment swaps and I expect the same will hold true for the Gen 5 ecms. This is why no one can get a factory V8 calibration to control the 6T75 even though the V6 ecm calibrations can. Back in the Gen 3 era, you could just do a transmission segment swap and run a 4T80 with an engine that never came with one... but that isn't possible with the Gen 4s and it will likely be true for the Gen 5s.
So to use the 6T75 (or future versions), you will almost certainly have to run a stand alone transmission controller. (unless you want to run the Ford version of the FWD 6 speed auto was offered with a V8 and try to adapt the Ford ECM to run an LS(x) engine....)
I was able to make a 2008 Corvette LS3 E38 ECM talk to a 2008 GM Truck 4L60E T42 TCM without any problems. And that was a Gen4 ECM.
However, it remains to be seen if a Gen5 ECM can be made to talk to a T42 TCM. But I wouldn't hold out hope that it will.
-ryan
------------------ OVERKILL IS UNDERRATED Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com
I was able to make a 2008 Corvette LS3 E38 ECM talk to a 2008 GM Truck 4L60E T42 TCM without any problems. And that was a Gen4 ECM.
However, it remains to be seen if a Gen5 ECM can be made to talk to a T42 TCM. But I wouldn't hold out hope that it will.
-ryan
Hybrid TCU and ECU work is alot easier outside of the HPT world... HPT binds the TCU and the ECU files together and refuses to support any hybrid file tcu/ecu stuff.
I was able to make a 2008 Corvette LS3 E38 ECM talk to a 2008 GM Truck 4L60E T42 TCM without any problems. And that was a Gen4 ECM.
However, it remains to be seen if a Gen5 ECM can be made to talk to a T42 TCM. But I wouldn't hold out hope that it will.
-ryan
That is interesting! The E38 in auto form works with the T42 TCM so the communication structure is there. I guess you swapped TCM's (or reflashed it) to the right T42 calibration. The LS4 guys have been trying to get the 6T75 to work for years, but haven't been successful. However, I don't think the 6T75 uses a T42 and that might be the issue.
Don's engine is an aluminum block though. It's an L92 (2008 Escalade) block, built out to 427cid, and has the LS7 heads/intake IIRC. This is why people often confuse it with actually being an LS7.
I remembered it was a truck engine... just checked the thread and it is indeed an aluminum block.
Originally posted by DKcustoms: It would probably be easier and smarter to stretch your Fiero so that you can mount the motor longitudinally near the back window and use a Porsche or Audi transmission. Either way, it would cost a lot.
If you were going to stretch the Fiero and mount the engine longitudinally why not just use the trans that came in the Vette (auto or manual) with the differential from the Vette? You could probably also use a trans+differential combo from a C6 Vette as well. This would reduce the complexity of the engine/trans/differential combo.
Originally posted by lateFormula: If you were going to stretch the Fiero and mount the engine longitudinally why not just use the trans that came in the Vette (auto or manual) with the differential from the Vette? You could probably also use a trans+differential combo from a C6 Vette as well. This would reduce the complexity of the engine/trans/differential combo.
Probably for the same reason the Vette transmission isn't used in the GTM builds, but rather a Porsche transmission is used. The Vette transmission does not bolt directly to the engine, and does not have the bell pattern to match up to the engine. The clutch is still on the engine side, and the input to the Vette transmission is designed to be driven via the torque tube, and not a typical input shaft for a transmission mounted to the engine. It would require much more work than an adapter plate to make it usable.
Originally posted by lateFormula: If you were going to stretch the Fiero and mount the engine longitudinally why not just use the trans that came in the Vette (auto or manual) with the differential from the Vette? You could probably also use a trans+differential combo from a C6 Vette as well. This would reduce the complexity of the engine/trans/differential combo.
The C5+ Vette transmissions have the differential after the gear sets vs. in front of them (like the Porsche/Audi transmissions). This places the axle location much further back than a Porsche/Audi... so the length from front of engine to axle centerline would be much too long.
That is interesting! The E38 in auto form works with the T42 TCM so the communication structure is there. I guess you swapped TCM's (or reflashed it) to the right T42 calibration. The LS4 guys have been trying to get the 6T75 to work for years, but haven't been successful. However, I don't think the 6T75 uses a T42 and that might be the issue.
I think the 6T75 uses a T43 TCM.
The 08 Corvette LS3 E38 ECM did communicate with a T42 TCM that was programmed with 08 Silverado 4L60-E programming; even though the 08 Corvette LS3 was never used with a 4-speed automatic or T42 TCM from the factory (it was only offered with a 6-speed manual or 6-speed automatic).
If an 08 LS4 ECM OS won't communicate with a T43 TCM with the same model year programming in it, then I would attempt to substitute that ECM OS with one from an 08 Corvette or 08 Truck and see if it will work. There could be something unique about the FWD OS used in the T43 TCM that prevents it from working with a LS4 OS in the ECM.
Or it could be a model year conflict if the ECM and TCM are programmed with non matching model year OS's.
Or it could be a model year / OS HP Tuners conflict issue, since their software doesn't like you mixing and matching ECMs and TCMs.
