quad4 or twincam with auto? (Page 1/2)
eesparza84 DEC 18, 08:26 AM
Has anyone done a swap with a quad4 with an auto trans? or the 2.4 twincam?
ive seen transmissions for sale 4t60e for the quad 4 on ebay and from my research the 2.4 twin cam had an auto option of the 4t45e.
now i know it wont be exciting or fun for most to drive a high revving 4 banger with an auto.
i know alot of trailblazing will need to be done. just wondering if anyone else has
82-T/A [At Work] DEC 18, 09:03 AM

quote
Originally posted by eesparza84:

Has anyone done a swap with a quad4 with an auto trans? or the 2.4 twincam?
ive seen transmissions for sale 4t60e for the quad 4 on ebay and from my research the 2.4 twin cam had an auto option of the 4t45e.
now i know it wont be exciting or fun for most to drive a high revving 4 banger with an auto.
i know alot of trailblazing will need to be done. just wondering if anyone else has




I can't say for a Fiero, but I did have this engine combination in a couple of Grand Ams that I owned back in the day.



The 2.4 LD9 TwinCam is the modern version of the Oldsmobile Quad-4. They're basically the same motor, but the TwinCam has counter-rotating shafts to improve (or reduce I should say) engine vibration. This is similar to what Porsche did on the 2.5 L4 in the 944.

The TwinCam LD9 motor, at least in my opinion, is a better engine than the Quad-4. It debuted in 1996, and it's last year of use was in 2002. Every year from 1997+ there was an improvement to the motor. Things like better oiling, higher compression, better water pump design, elimination of EGR, etc. So try to get the later years if possible, but almost everything is interchangeable from 1996-2002... though if you want the higher compression, you need to rebuild it.

The horsepower rating is 150hp / 150lbs of torque, though in the later years, it was more like 160hp and 160ft-lbs of torque.

That doesn't seem like a lot, but in a Chevy Cavalier / Pontiac Sunfire, when mated with the 5-Speed Getrag, it was not uncommon to get numbers into the high 6-second range for 0-60. It would not be too far off with a 4T60E.


Honestly, I really, really liked the TwinCam, and there's a lot of performance upgrades you can do with them. I can't remember them all, but there's one that's silly-named, the "Secret Cam Swap." This is where you take (don't quote me), something like the intake cam from a 1994 Quad-4, and an exhaust cam from a 1995 Quad-4, and install it in the TwinCam, and you immediately get another 12 horsepower (it could be the other way around exhaust / intake, so please look it up before you take my word for it). There are larger throttle bodies, the intakes can swap out, and there was even a dealer-optioned "GM Performance Parts" supercharger that would bolt directly in place of the intake manifold for Cavalier and Sunfire... but I haven't been able to find one.

Anyway, it's a fantastic motor. The only thing I'd say though is... if you're going to go that route, you might as well just go a little bit newer. Unless you already have one... there is a whole newer generation of GM motors. The Ecotec is also really great... the 2.0 LNF Turbo Motor is insane... (came in the Solstice and the Cobalt SS). There's also just the normally aspirated 2.4L one, which is a VVT version of what is basically the TwinCam (though redesigned). Those are also readily available now, and it might be cheaper / easier to go with one of those.
eesparza84 DEC 18, 11:07 AM

quote
Originally posted by 82-T/A [At Work]:
I can't say for a Fiero, but I did have this engine combination in a couple of Grand Ams that I owned back in the day.



The 2.4 LD9 TwinCam is the modern version of the Oldsmobile Quad-4. They're basically the same motor, but the TwinCam has counter-rotating shafts to improve (or reduce I should say) engine vibration. This is similar to what Porsche did on the 2.5 L4 in the 944.

The TwinCam LD9 motor, at least in my opinion, is a better engine than the Quad-4. It debuted in 1996, and it's last year of use was in 2002. Every year from 1997+ there was an improvement to the motor. Things like better oiling, higher compression, better water pump design, elimination of EGR, etc. So try to get the later years if possible, but almost everything is interchangeable from 1996-2002... though if you want the higher compression, you need to rebuild it.

The horsepower rating is 150hp / 150lbs of torque, though in the later years, it was more like 160hp and 160ft-lbs of torque.

That doesn't seem like a lot, but in a Chevy Cavalier / Pontiac Sunfire, when mated with the 5-Speed Getrag, it was not uncommon to get numbers into the high 6-second range for 0-60. It would not be too far off with a 4T60E.


Honestly, I really, really liked the TwinCam, and there's a lot of performance upgrades you can do with them. I can't remember them all, but there's one that's silly-named, the "Secret Cam Swap." This is where you take (don't quote me), something like the intake cam from a 1994 Quad-4, and an exhaust cam from a 1995 Quad-4, and install it in the TwinCam, and you immediately get another 12 horsepower (it could be the other way around exhaust / intake, so please look it up before you take my word for it). There are larger throttle bodies, the intakes can swap out, and there was even a dealer-optioned "GM Performance Parts" supercharger that would bolt directly in place of the intake manifold for Cavalier and Sunfire... but I haven't been able to find one.

Anyway, it's a fantastic motor. The only thing I'd say though is... if you're going to go that route, you might as well just go a little bit newer. Unless you already have one... there is a whole newer generation of GM motors. The Ecotec is also really great... the 2.0 LNF Turbo Motor is insane... (came in the Solstice and the Cobalt SS). There's also just the normally aspirated 2.4L one, which is a VVT version of what is basically the TwinCam (though redesigned). Those are also readily available now, and it might be cheaper / easier to go with one of those.



appreciate the response! and all the data. while yes the ecotecs look great, they are a little more intimidating to me, alot of electronics to work on and wiring to figure out. even more so than the quad 4 or twin cam which will be a task in itself... maybe if i went with a newer ecotec with the 6speed auto trans as a package they could be a good upgrade.
82-T/A [At Work] DEC 18, 11:38 AM

quote
Originally posted by eesparza84:

appreciate the response! and all the data. while yes the ecotecs look great, they are a little more intimidating to me, alot of electronics to work on and wiring to figure out. even more so than the quad 4 or twin cam which will be a task in itself... maybe if i went with a newer ecotec with the 6speed auto trans as a package they could be a good upgrade.




Keep in mind that the Quad-4 is an OBD1-powered engine (-1995). The TwinCam was introduced in the transition to OBD2 in 1996... so all TwinCam motors are OBD2.

I found this thread, in which I apparently posted in it, and get a little hot in some of my responses, haha... https://www.fiero.nl/forum/...090219-2-079492.html

The thread is 19 years old, so I was almost half my age then, so that explains why.

The only update I'd add here is that you can still run factory Fiero sensors on the engine (if you can find the slots for them), and run the old gauges. But depending on the ECM you use... some GM vehicles **** a brick when you disconnect the gauge cluster... I think (someone correct me if I'm wrong) because sometimes VATS is part of the cluster. I know that in both my Grand Ams... if I disconnected the gauge cluster, the car would not run.


But, something to consider... there's a few other things in there.

You won't need to get any adaptor plates as mentioned in some of the responses either, because the TwinCam literally came with a 4T60E attached to it, and you can just get a 4T60 (non-E) or 4T40 from a Quad-4 and it will mount up all the same. And then the only thing you need to do is drill a new hole in your subframe, and get a new front motor mount.

Wiring shouldn't be too hard.

With the TwinCam though, you can also go with an aftermarket fuel injection system also... like a Holley or FAST EZ-EFI system. Both of which will more or less self-learn. Lots of support for these things with the MicroSquirt and MegaSquirt too.
82-T/A [At Work] DEC 18, 12:50 PM
You've re-peaked my interest.

I just found an extremely rare SuperCharger kit for the LD9. This is the first one I've literally ever seen on eBay. Not too many people got them, but it bolts right up to the LD9 and re-uses everything on the engine, replaces the intake, and the factory TB bolts to it. It was a GM performance parts factory-ordered option.

https://www.ebay.com/itm/267410392633

Not gunna lie... I may buy this if you don't... haha... I've always wanted a TwinCam Fiero. It even comes with the ECM, meant for an automatic (meaning it's been reflashed to support the supercharger and larger injectors).

If it's still there by Monday morning, I'm buying it.
eesparza84 DEC 18, 12:57 PM

quote
Originally posted by 82-T/A [At Work]:
Keep in mind that the Quad-4 is an OBD1-powered engine (-1995). The TwinCam was introduced in the transition to OBD2 in 1996... so all TwinCam motors are OBD2.

I found this thread, in which I apparently posted in it, and get a little hot in some of my responses, haha... https://www.fiero.nl/forum/...090219-2-079492.html

The thread is 19 years old, so I was almost half my age then, so that explains why.

The only update I'd add here is that you can still run factory Fiero sensors on the engine (if you can find the slots for them), and run the old gauges. But depending on the ECM you use... some GM vehicles **** a brick when you disconnect the gauge cluster... I think (someone correct me if I'm wrong) because sometimes VATS is part of the cluster. I know that in both my Grand Ams... if I disconnected the gauge cluster, the car would not run.


But, something to consider... there's a few other things in there.

You won't need to get any adaptor plates as mentioned in some of the responses either, because the TwinCam literally came with a 4T60E attached to it, and you can just get a 4T60 (non-E) or 4T40 from a Quad-4 and it will mount up all the same. And then the only thing you need to do is drill a new hole in your subframe, and get a new front motor mount.

Wiring shouldn't be too hard.

With the TwinCam though, you can also go with an aftermarket fuel injection system also... like a Holley or FAST EZ-EFI system. Both of which will more or less self-learn. Lots of support for these things with the MicroSquirt and MegaSquirt too.



was there 4t60 non e used with a quad 4? i saw e versions on ebay, but have not delved deep enough yet, between a non e trans and an after market system like you mentioned, wouldnt really need much in the way of wiring or ecm stuff for the twin right?
olejoedad DEC 18, 01:14 PM
Ok
quote
Originally posted by eesparza84:


was there 4t60 non e used with a quad 4? i saw e versions on ebay, but have not delved deep enough yet, between a non e trans and an after market system like you mentioned, wouldnt really need much in the way of wiring or ecm stuff for the twin right?



You would need the ECU and wiring harness for the swap engine, whatever you choose.

And yes, there will be some wiring involved to interface with the Fiero chassis-side electrical plugs for power, grounds, gages etc.

[This message has been edited by olejoedad (edited 12-18-2025).]

cartercarbaficionado DEC 18, 06:28 PM

quote
Originally posted by eesparza84:

Has anyone done a swap with a quad4 with an auto trans? or the 2.4 twincam?
ive seen transmissions for sale 4t60e for the quad 4 on ebay and from my research the 2.4 twin cam had an auto option of the 4t45e.
now i know it wont be exciting or fun for most to drive a high revving 4 banger with an auto.
i know alot of trailblazing will need to be done. just wondering if anyone else has


i know someone who swapped a twincam from a grand am into their fiero with the stock coil packs and fuel injection from the grand am...im not quite sure how good old doug did it especially with the turbo on the stock plastic manifold he was using but it did work and was fast for a bone stock twincam with 4.5 psi of boost..i think he may have gotten the stock ecm tuned to ignore the cluster and emissions so he could vastly simplify it but im not 100% on what he did since i only saw it like 6 times but truthfully theres alot easier swaps to do and im guessing you dont like manuals or just dont have the parts to convert
82-T/A [At Work] DEC 18, 08:12 PM

quote
Originally posted by eesparza84:

was there 4t60 non e used with a quad 4? i saw e versions on ebay, but have not delved deep enough yet, between a non e trans and an after market system like you mentioned, wouldnt really need much in the way of wiring or ecm stuff for the twin right?




Yes... ok, I think I understand why you're asking this.

The bell housing of the Quad-4 is identical to that of the TwinCam. That means that any transmission used on the Quad-4, will work on both the Quad-4 and the TwinCam.

The 4T60 (non-E) was pretty common through like 1994. The 4T60E was first used in 1991 if I remember, and basically was the transmission of choice for everything in 1995. You can use either the 4T60 or 4T60E as long as it has the Quad-4 / Twin Cam bolt pattern.
Raydar DEC 18, 10:04 PM

quote
Originally posted by eesparza84:

Has anyone done a swap with a quad4 with an auto trans? or the 2.4 twincam?
ive seen transmissions for sale 4t60e for the quad 4 on ebay and from my research the 2.4 twin cam had an auto option of the 4t45e.
now i know it wont be exciting or fun for most to drive a high revving 4 banger with an auto.
i know alot of trailblazing will need to be done. just wondering if anyone else has



I've not done the swap, but I've got a 46 page PDF "how to" installation/parts manual. It doesn't mention automatics that I recall, however.
If you'll PM me your email address, I'll send it to you.

------------------
Raydar
88 Formula IMSA Fastback. 4.9, NVG T550

Praise the Lowered!