First off, I am new here. If I posted this in the wrong subforum or otherwise have done something in need of correction, please let me know.
I am collecting information on the car I believe will be my first build to determine if this car really is the one, and I still have a lot of questions.
Let's start off with my most fundamental problem. I am about 6'6". I tried sitting in one once, and it didn't work out super great. Granted, I was not permitted any extensive amount of time to adjust the seat to my liking, and it usually takes me quite a bit of adjustment to get comfortable in any car, including my 3/4 ton Suburban (lol). What can I do, if anything, to physically fit myself into the car? Non-stock seats and seat mounts? Is this car viable for me space-wise?
Secondly: I have seen several LS4 swap threads already, and it certainly looks like the best/simplest plan of action for making a stupid-fast Fiero. Can a 4T65E-HD be built to stand 500+ RWHP? If not, what transmission will work best? Does a 4T80E fit under there? How do these different engine and transmission swaps affect the weight balance of the car?
Third: Brakes and suspension. I want a car that can stop and handle. I know 88's have much better suspension than earlier years, but how good can these things really corner? What is out there in the way of tuneable suspension and general handling upgrades? Also, what kind of high-power brakes are available for this platform, and how fast can they make it stop?
Finally: Boost. I am looking to put a modest amount of boost (5-10psi) through the motor. Will a stock LS4 survive this? Will there be room anywhere for an intercooler that doesn't exacerbate any weight balance issues?
Any answers I receive are greatly appreciated. One last thing to keep in mind is that this is not an incoming build thread. I might be another year of research away from being certain enough on a Fiero build to begin parts collection, and 3-5 years away from having the required circumstances to acquire the car itself and start the build. My username is quite relevant at this stage.
The LS4 is a good engine, but perhaps not the simplest (and definitely not the cheapest) option for going stupid fast. The LS4 has the starter mounted on the transmission, so the 4t65e that comes mated to the LS4 has a bell housing cast specifically for that engine. Using other transmissions may be possible (the F40 MT2/MU9 manual is), but requires modifying the bell housing to fit the starter. The 4t65e can be built to handle well more than 500 HP, and it's the transmission used by most all of the Fieros with the fastest 1/4 mile times on here. Those are mostly using a Series II 3800 Supercharged engine, with an intake swap to delete the supercharger, and go with a big turbo instead.
The LS4 is also still a relatively large engine. It can handle 5-10 PSI with stock internals, but fitting all the piping into a stock sized Fiero engine bay is going to require some fancy engineering. There's a stretched Murcielago replica owned by dratts on here, which has an LS4 with the turbo kit from Cartuning that was designed to fit the original LS4 vehicles. I don't think it'll fit well in a stock Fiero bay though.
If you want cheap, easy, and stupid fast, the 3800 Series II SC (L67) engine is probably the best option to start with. A Series III (L36) engine would also work well, but they're less abundant in the yards, and can be more expensive to get. Swapping the intake manifold/blower out for the N/A version manifold and going with a turbo will let you make much more power after the bolt ons for the supercharged engine will plateau.
The LS4 is a good engine, but perhaps not the simplest (and definitely not the cheapest) option for going stupid fast. The LS4 has the starter mounted on the transmission, so the 4t65e that comes mated to the LS4 has a bell housing cast specifically for that engine. Using other transmissions may be possible (the F40 MT2/MU9 manual is), but requires modifying the bell housing to fit the starter. The 4t65e can be built to handle well more than 500 HP, and it's the transmission used by most all of the Fieros with the fastest 1/4 mile times on here. Those are mostly using a Series II 3800 Supercharged engine, with an intake swap to delete the supercharger, and go with a big turbo instead.
The LS4 is also still a relatively large engine. It can handle 5-10 PSI with stock internals, but fitting all the piping into a stock sized Fiero engine bay is going to require some fancy engineering. There's a stretched Murcielago replica owned by dratts on here, which has an LS4 with the turbo kit from Cartuning that was designed to fit the original LS4 vehicles. I don't think it'll fit well in a stock Fiero bay though.
If you want cheap, easy, and stupid fast, the 3800 Series II SC (L67) engine is probably the best option to start with. A Series III (L36) engine would also work well, but they're less abundant in the yards, and can be more expensive to get. Swapping the intake manifold/blower out for the N/A version manifold and going with a turbo will let you make much more power after the bolt ons for the supercharged engine will plateau.
The extra cost of the LS4 doesn't much bother me, as my current plan is to look in a junkyard for a wrecked Impala/Monte Carlo SS with an undamaged driveline and pluck it wholesale for use in the Fiero. I'll definitely take a better look through those 3800 Series II threads though, and thanks for the mention of that motor.
What about a turbo that sits like some of the TT kits for modern Vettes and Camaros? The turbos on those kits sit outside the engine bay, further down the exhaust towards the tailpipe. It's more ducting for the intake side, but saves engine compartment space and exhaust ducting. It sure looks like I could appropriate some of the trunk space for the turbo/TT's if I went that route and the turbo(s) would fit, it'd just be a matter of where to put the intercooler and ducting. Am I missing anything?
I'm glad to hear the 4T65E can be built nice and strong; I'll have to find those threads you mentioned where they put 500+ RWHP through the trans and see what parts they built them with. Thanks for your response.
Let's start off with my most fundamental problem. I am about 6'6". I tried sitting in one once, and it didn't work out super great. Granted, I was not permitted any extensive amount of time to adjust the seat to my liking, and it usually takes me quite a bit of adjustment to get comfortable in any car, including my 3/4 ton Suburban (lol). What can I do, if anything, to physically fit myself into the car? Non-stock seats and seat mounts? Is this car viable for me space-wise?
Two things that help. First... a Fiero with a sunroof gives you a bit more head room. Second... there is a way to make the seat track lower. It's often done with Fieros that have had the "choptop" treatment.
I recently posted my experience with driving a choptop Fiero.
A friend of mine owns an Archie choptop with a Corvette V8.*Beautiful car, lots of power. He wanted me to co-drive it at a local autocross. Sounds like fun, eh? Nope. I don't fit. I''m 6'3" and it's uncomfortable as hell trying to sit in that car. Add a helmet to the mix and it's next to impossible. After a couple runs through the course I said thanks but no thanks. It's much more fun driving my "bubble-top" 88 Formula.
Having said all that, many guys taller than me have posted here who have no issues sitting in their (non-choptop) Fieros. It also depends on where the extra height is... from the waist up or in the legs.
* This is not the car for you (or me). (Yes, that's the one I was trying to autocross.)
[This message has been edited by Patrick (edited 08-02-2015).]
Having said all that, many guys taller than me have posted here who have no issues sitting in their (non-choptop) Fieros. It also depends on where the extra height is... from the waist up or in the legs.
* This is not the car for you (or me). (Yes, that's the one I was trying to autocross.)
So in your experience, a Fiero is not a viable car at your height? Even with this modification that theoretically should provide more space? EDIT: Oops, just read the Archie page on choptops and it is for a lower top, providing less headroom. I thought it was cutting the roof off to make it higher... My bad, haha. END EDIT. What about removing the factory seating in favor of more minimal seats like a low profile bucket seat? Would that get it done?
[This message has been edited by JustResearch (edited 08-02-2015).]
Oops, just read the Archie page on choptops and it is for a lower top, providing less headroom. I thought it was cutting the roof off to make it higher... My bad, haha.
Geez, you are new to this!
quote
Originally posted by JustResearch:
What about removing the factory seating in favor of more minimal seats like a low profile bucket seat? Would that get it done?
With the factory seats and the tweaked mounting tracks, your butt will practically be on the floor as it is.
You may find you have no issue at all fitting in an unmodified Fiero... if you take your time adjusting the seat.
quote
Originally posted by JustResearch:
I was not permitted any extensive amount of time to adjust the seat to my liking...
[This message has been edited by Patrick (edited 08-02-2015).]
I am collecting information on the car I believe will be my first build to determine if this car really is the one, and I still have a lot of questions.
Let's start off with my most fundamental problem. I am about 6'6". I tried sitting in one once, and it didn't work out super great. Granted, I was not permitted any extensive amount of time to adjust the seat to my liking, and it usually takes me quite a bit of adjustment to get comfortable in any car,
Third: Brakes and suspension. I want a car that can stop and handle. I know 88's have much better suspension than earlier years,
Finally: Boost. I am looking to put a modest amount of boost (5-10psi) through the motor. Will a stock LS4 survive this? Will there be room anywhere for an intercooler that doesn't exacerbate any weight balance issues? .
First off welcome to the forum JustResearch!
Secondly everything Dobey mentioned.
You have found the best website for information in regard to Fiero's on the internet, imo.
So with the large variety of "go fast" platforms that you could choose to build, why the Fiero? Im sure your aware of the fact; you can go fast for lower cost with something other than a Fiero?
So for what ever your reason, I got to assume your just fond of Fieros, so am I and I love my Ls4 conversion, couldn't of done it with out the contributions of the members on this website. With that being said, when I looked into investing time and money into Fieros, I basically came to the conclusion it would have to be an 88 or nothing. Not trying to minimize anything about the pre 88s, the 88 seemed to make the most logical sense for me jumping into Fieros.
You mentioned how physical comfort may be a factor in regard to choosing the Fiero platform, so It may be worth the effort to find a Fiero and see if the seat adjustments and head room will meet your expectations. Just my 2 cents.
Patrick, thank you for that information. Given that you, at 6'3", can fit in an unmodified Fiero, I am pretty confident that with this seat modification you describe, combined with adequate adjustment time, I could fit myself into a Fiero.
quote
Originally posted by Jims88:
First off welcome to the forum JustResearch!
Secondly everything Dobey mentioned.
You have found the best website for information in regard to Fiero's on the internet, imo.
So with the large variety of "go fast" platforms that you could choose to build, why the Fiero? Im sure your aware of the fact; you can go fast for lower cost with something other than a Fiero?
So for what ever your reason, I got to assume your just fond of Fieros, so am I and I love my Ls4 conversion, couldn't of done it with out the contributions of the members on this website. With that being said, when I looked into investing time and money into Fieros, I basically came to the conclusion it would have to be an 88 or nothing. Not trying to minimize anything about the pre 88s, the 88 seemed to make the most logical sense for me jumping into Fieros.
You mentioned how physical comfort may be a factor in regard to choosing the Fiero platform, so It may be worth the effort to find a Fiero and see if the seat adjustments and head room will meet your expectations. Just my 2 cents.
Again welcome to the Forum
Jim
"Why Fiero?" is answered with several reasons: Small and light, mid-engined, GM-built for ease of parts acquisition, cheap purchase price especially as a project car, and what appears to be great modification potential. Also, I love the aesthetic of the GT models, so there's that. My purpose with this car is not just go as fast as possible, I want a car I can eventually use at the track for sportscar racing. Handling, braking, and acceleration mean more to me than just top speed. The platform may turn out to be viable/ideal, and it may not. I am wiling to spend more money for having something mid-engine and with the great aesthetic as opposed to just doing an RX-7 LS swap or the like.
I too will only get myself into an 88 GT. Not to bash on anything else, of course; the GT is in my opinion the best looking Fiero and the 88's superior suspension will be paramount for my usage.
I've already seen that video, and I will definitely read that thread, thanks for posting it here. Of course, if I can't get myself clearance for both my head and a helmet, this platform may be a no-go as a sportscar racing deal, but it looks like I'll just have to try shoehorning myself into one to know, now doesn't it? Thanks.
The guy building the car will likely be selling everything involved. It should get you all the basics, then from there its making it fit in a Fiero engine bay... which I think there is room.
The guy building the car will likely be selling everything involved. It should get you all the basics, then from there its making it fit in a Fiero engine bay... which I think there is room.
Not ready to buy parts yet, but will still definitely check out that thread. Also... your fiero... it's beautiful...
Lastly, not looking to buy a turbo kit. My current plan is to buy the turbo/turbos of proper size for my desired PSI at my desired flow rate, then work out the ducting and proper capacity intercooling myself. Looks like mounting further down the exhaust out of the engine compartment will be easiest, and whether I go TT or just one depends on how I end up routing exhaust. If it'll be easier to join the exhaust before the muffler, I'll use one. Otherwise I'll use two. If I'm missing a crucial detail, let me know of courses
Originally posted by JustResearch: The extra cost of the LS4 doesn't much bother me, as my current plan is to look in a junkyard for a wrecked Impala/Monte Carlo SS with an undamaged driveline and pluck it wholesale for use in the Fiero. I'll definitely take a better look through those 3800 Series II threads though, and thanks for the mention of that motor.
What about a turbo that sits like some of the TT kits for modern Vettes and Camaros? The turbos on those kits sit outside the engine bay, further down the exhaust towards the tailpipe. It's more ducting for the intake side, but saves engine compartment space and exhaust ducting. It sure looks like I could appropriate some of the trunk space for the turbo/TT's if I went that route and the turbo(s) would fit, it'd just be a matter of where to put the intercooler and ducting. Am I missing anything?
I'm glad to hear the 4T65E can be built nice and strong; I'll have to find those threads you mentioned where they put 500+ RWHP through the trans and see what parts they built them with. Thanks for your response.
Remember that in the Fiero, the entire exhaust system is basically in the engine bay area. The STS turbo kits for the Vettes/Camaros/etc… aren't so simple either. Putting the turbo in the rear of those cars requires a lot of additional intake piping to be run all the way from the rear of the car to the front. They also take advantage of the very long intake tube between the turbo and throttle body as a means of cooling the compressed air charge.
It may be possible to fit a smaller turbo in the engine bay with an LS4/4t65e, but it's going to be a tight fit. You could probably fit a turbo or two where the muffler in the Fiero is, but you will likely need to lose at least the bottom of the trunk to do so. If you're fine with losing the trunk space, then that's certainly an option for you.
Rather than getting stuck on the LS4 + turbo though, what is it that you really want out of a Fiero with an engine swap? For some people, 250 HP is more than enough, and for others 900+ is still not enough. Are you trying to build something that will run 9 second 1/4 mile times, or are you trying to build something you could drive daily, but take to a track on the weekend or such? Are you going to AutoX it, or run it on a proper road course?
A whole lot can change in 5 years. For me, what I've wanted to do with a Fiero build has changed quite a lot over the last 15 years that I've owned various Fieros. At first I was set on a Northstar, then I switched to wanting an LS6, and at some point finally settled on an LS4 and started buying some parts to get me there. Then, even with the LS4, what I've wanted to do with it, has changed quite a lot over the past 5-6 years. At first I was just going to do a standard refresh and do a couple of small things to improve performance, such as deleting the DoD feature, and shaving the heads to bump compression. Then I decided I wanted to convert it to a 4.8 bottom end as a bit of insurance to extend the redline to a higher RPM. Then I learned about the VVT support that was added into some of the Gen IV engines starting with the L92 in the 08 Escalade, and decided I wanted to retrofit it onto my LS4. And now I've just gone off the deep end with my build, but I've refined it into something quite unique, and which I feel will give me a decent challenge, and be an incredible engine to drive. It almost feels like a lie to even call it an LS4 any more.
Remember that in the Fiero, the entire exhaust system is basically in the engine bay area. The STS turbo kits for the Vettes/Camaros/etc… aren't so simple either. Putting the turbo in the rear of those cars requires a lot of additional intake piping to be run all the way from the rear of the car to the front. They also take advantage of the very long intake tube between the turbo and throttle body as a means of cooling the compressed air charge.
It may be possible to fit a smaller turbo in the engine bay with an LS4/4t65e, but it's going to be a tight fit. You could probably fit a turbo or two where the muffler in the Fiero is, but you will likely need to lose at least the bottom of the trunk to do so. If you're fine with losing the trunk space, then that's certainly an option for you.
Rather than getting stuck on the LS4 + turbo though, what is it that you really want out of a Fiero with an engine swap? For some people, 250 HP is more than enough, and for others 900+ is still not enough. Are you trying to build something that will run 9 second 1/4 mile times, or are you trying to build something you could drive daily, but take to a track on the weekend or such? Are you going to AutoX it, or run it on a proper road course?
A whole lot can change in 5 years. For me, what I've wanted to do with a Fiero build has changed quite a lot over the last 15 years that I've owned various Fieros. At first I was set on a Northstar, then I switched to wanting an LS6, and at some point finally settled on an LS4 and started buying some parts to get me there. Then, even with the LS4, what I've wanted to do with it, has changed quite a lot over the past 5-6 years. At first I was just going to do a standard refresh and do a couple of small things to improve performance, such as deleting the DoD feature, and shaving the heads to bump compression. Then I decided I wanted to convert it to a 4.8 bottom end as a bit of insurance to extend the redline to a higher RPM. Then I learned about the VVT support that was added into some of the Gen IV engines starting with the L92 in the 08 Escalade, and decided I wanted to retrofit it onto my LS4. And now I've just gone off the deep end with my build, but I've refined it into something quite unique, and which I feel will give me a decent challenge, and be an incredible engine to drive. It almost feels like a lie to even call it an LS4 any more.
For power, I want 500-600HP that is not hidden behind a massive boost threshold or made mushy and unresponsive by huge turbo lag. This means I will need a V8, and have 2 options: Huge cam and full motor rebuild for high compression (expensive rebuild and has massive lope, but is more compact) or stock LS4 with better intake and 10lbs boost(expensive turbos and complex ducting, but much more driveable on the street and doesn't sound as obnoxious). I'd rather have the TT LS4 setup, to be honest. The extra headaches of the turbos are worth it to me over the simplicity of NA due to being more efficient, driveable, and similar in cost if not cheaper.
I am well aware that I will need ducting running to the front of the car to an intercooler and then back to the engine for the intake. Current plan is to set it up for NA first and once I've figured out an elegant solution to route ducting and place an intercooler, then worry about the turbos. The trunk space means very little to me. If I have to lose half of it to turbos, that'll be just fine. If I need to store anything in this car, I'll just have to forego a passenger
I want to run it on a proper road course, but I will likely use the quarter mile to tune grip and acceleration without optimizing weight distribution for drag racing. Autocross viability would be fun too, but is not mandatory. Essentially, I want a generally great performing little car that accelerates fast (lots of power and grip), corners hard (88 spec suspension and any mods I can find here that appreciably improve performance), and stops quick (hopefully C5 Vette brakes in front and LeBaron brake conversion in back).
You are certainly right that I may change my mind in the meantime, but that's why I'm still researching and not collecting parts yet. I figure if I keep the same vision for such a long time while researching, it's something I really do want. This thread's purpose is to better flesh out what I could do with a Fiero, not to start a build.
Brakes - You can use Corvette rotors with the 88 calipers. The Lebaron setup is used on pre-88's.
Are the calipers sufficient for a 500-600HP car on an autocross/road course, or are they just good enough for the street? Either way, I didn't know this, and it's all the more reason to go with an 88. Thank you!
Didn't read the whole thread, so this may have been covered.
Have you tried pulling the seat completely out (takes about 2 minutes with a 13mm socket, ratchet, U-joint and 3-6" extension) and just sitting on the floor? If that doesn't work for you, you sure won't get a seat that will work.
Regarding seats, you may have to get a Kirkey bare aluminum racing seat and bolt it directly to the original studs in the floor. This is the most headroom you're going to get in a Fiero with a seat. As mentioned, a sunroof gives you about an inch more headroom than a slick top. More accurately, the lack of headliner above your head gives you more headroom in a sunroof car than a slick top car.
[This message has been edited by Will (edited 08-03-2015).]
Having built a few LS4's for people. I have built stock 305 hp to turbo LS4 in a kit car 650 hp. My take on building a turbo LS4 can be done, but to do turbo or turbos you will have to lose the trunk. As far as inter cooling look into air water inter cooling takes less room and you only have to run smaller coolant lines instead of big air lines with the lag induced with that long run. The last one I built was a complete rebuild and balance with the DOD removed and GM performance lifters, springs and a LS7 cam. That one turned 450 hp at the crank and was a hand full to drive. There is a point were you have more power than you can use.
Just my 2 cents
Joe Sokol
------------------ 85 SE Daily driver with a 3.4 DOHC OBD II 88 Formula/GT 4.9 Allante Intake (My Baby) www.fieroking.com
(Yes, that's the one I was trying to autocross.)
