Project MIDTRBO... '88 Fiero GT

[ALLTRBO]

Upon request, I'm posting my '88 Fiero GT V6 turbo build here. This thread won't be the full build thread, rather major updates that may be of interest. The full build thread is here, on Pennock's Fiero Forum...
http://www.fiero.nl/forum/Forum1/HTML/078498.html

This project is the main reason I didn't buy a Camaro SS, not because of cost, but because I don't need a V8 that'll be wasted 9-ways from Sunday by a little V6 car. That's just embarrasing. Plus, I just LOVE the LLT and its technology, and the lighter weight of the V6 Camaro. Anyway...

It's an '88 Fiero GT 5-speed with a '90 Turbo Grand Prix 3.1l 60degreeV6 shortblock (for now) and a late Gen III (3400) top end being pushed by a Borg/Warner S258 with a .82 A/R T3 exhaust housing machined to fit, all controlled by a '730 ECU. I'm guessing it'll make somewhere around 350whp on ~12 psi, maybe a bit more. This is the first step. It'll help me get a base tune down and figure out the details I want to change about the real shortblock build.

Later on I'm going to build up a stout "3200" destroker shortblock using a 3500 block and a 2.8 crank with Diamond pistons (.100 over 3400 pistons) and 5.85" forged SBC rods, and I'll probably have the top end ported and a decent matching cam installed. Along with the huge W/A IC setup that I'm building for it and serious fuel delivery and a twin-disk clutch upgrade, the setup should support about 600whp on high boost (30+ psi) and race gas, with a smooth enough torque delivery that the eggshell Getrag 282 might handle it (if not, I'll upgrade to the F23, a slightly stronger but similar 5-speed). It's getting a sport/race exhaust, basically a high-flow regular exhaust, then an electronic cutout that will bypass that and route back into the tailpipes. This will keep the neighbors happy in "sport mode" and me happy in "race mode", and anywhere in between.

The suspension is also being worked over. The '88s had a suspension redesign that much improves on all earlier Fieros. It's already all rebuilt, and I'm working out the proper way to lower it without screwing up the geometry, which is an easy thing to do with the '88s (screw up the geometry, that is). There are ways... The brakes have been upgraded, and the weak wheel bearings will also be seriously upgraded, as will the wheel/tire combo.

I'm doing some body and interior mods also, and will have a custom high-quality paint job.

I recently had to sell my twin-turbo '90 IROC-Z [IMG]http://60degree*******/forum/images/smilies/icon_sad.gif[/IMG] to get the reliable daily driver 2010 Camaro, and I'm selling my 11-second AWD Talon and my stock AWD Talon, so the Fiero is going to be my only real sportscar to play with.
Because of that, I'm aiming for ZR1 performance levels... Well, other than top-speed, reliability, ride quality and refinement. I'll save about $80,000 so that's okay with me. [IMG]http://60degree*******/forum/images/smilies/smile.gif[/IMG] The initial build with the 3.1 shortblock is about 80% done.

Let me know what you think. If there's any questions I'll try to answer them, but most of it is covered in the build thread (be prepared for lots of reading). I won't be updating the thread here regularly, so don't fret if I haven't posted in a while.

BTW, a modest 350whp in this light Fiero will be equivalent to about 440whp in an SS, and the Fiero's 600whp will be equivalent to about 760whp in an SS. Though, the Fiero will hook up easier and still handle much better doing it. Oh, and it'll stop fast too.

[ALLTRBO]

Here are a few pics to whet the appetite.





And here are couple pics of the goodies...





(The turbo is just resting on the flange)

[2010 SSRS]

wow, that is going to be a scary ride.

[ALLTRBO]

The car looks like this for now,




...but will look similar to this (only better) when it's done.

[ALLTRBO]

This is part of a conversation on the 60V6 forums (not in the build thread) when asked why I'm going with a destroker 3.2 rather than the 3500 block that it's based off of. Here are the main reasons...

*Less torque: With equivalent components (top end/cam/etc) a smaller displacement will usually make almost as much power but at a higher rpm. The torque, however, has a higher percentage difference. Look at the stock (late) 3100 vs. 3400 hp and torque for examples. The 3400 has 10 more hp (185 vs 175) but 15-20 more lb/ft. Though the 3400 has 6.9% more displacement (3350cc/3135cc), it has only 5.7% more hp, but 7.7% more torque.
They are, of course, identical other than the bore and slightly bigger TB on the 3400. So to make an even comparison put the 3400 TB on the 3100 and it might gain ~5 hp, bringing the hp advantage of the 3400 to only ~2.8%, but not really changing the peak torque. I've seen several examples of this, stock and modified, some to a more extreme degree...
I want less off boost torque to go easier on the tranny between shifts. It isn't much of a difference, but every bit adds up. Shock loading is what kills trannies, not really horsepower. However, I still want the reasonable off-boost torque of a V6 over a blatty l4 so I wouldn't go that route (been there done that with my Talon... no thanks).

*Rod/Stroke ratio: The 3100/3400 is 1.72:1, the 3500 is 1.79:1, and the "3200" will be 1.96:1
A higher rod/stroke ratio allows more resistance to detonation, which will allow me to run a bit more boost on the same octane (possibly making up for that slight hp drop without retaining that off-boost torque). In addition, the maximum piston speeds are slower.

*Less rotating mass: There will be less shock loading on the tranny between shifts, again. It isn't a lot of a difference, but every bit adds up. It will also use up less hp to turn the crankshaft, mainly at high rpm. Not only because the crankshaft is lighter, but also because the rod journals and the lighter counterweights take away weight from the outside diameter of the rotation, where it counts most.

*Rod availability: Using the 76mm crank and the 3400 pistons (.100 over) will allow me to use 5.85" SBC rods (slightly machined of course) for the perfect piston height vs. quench clearance vs. head gasket thickness, and very stout 5.85" SBC rods are somewhat easy to find, hence easier and cheaper than custom options that will handle ~650 hp.

*Crank strength: This one probably doesn't differ as compared to the forged 3500 crank, but comparing to the 3400 steel crank, there is more overlap between rod journals with the 2.8 crank. Many say that it doesn't matter because no one has ever broken a 3400 crank, but I don't think anyone has ever pushed ~650hp through one either (correct me if I'm wrong).

*RPM capability: All of the above adds up to a rotating assembly that'll probably beg for 7500 rpm with a few valvetrain mods and mild turbo cam upgrade, and intake and head porting (I'm talking about you, Ben. [IMG]http://60degree*******/forum/images/smilies/icon_wink.gif[/IMG] ). Maybe even 8000rpm. My heart skips a few beats at the thought of a jet-like spooling and screaming 7500-8000 rpm 60V6. The 282 doesn't care to shift above 7k from what I hear, but I think that's covered by an aluminum flywheel and lighter rotating assembly, along with my friend Will (aka: "The Dark Side of Will" on RFT and "Will" on PFF) with his awesomz 282 rebuild skillz, heh.

I could also add some panzy-arse reason like the extra gas mileage it could theoretically get, but this car isn't being built for economy, though it'll still be good enough. [IMG]http://60degree*******/forum/images/smilies/smile.gif[/IMG]

[ALLTRBO]

Originally Posted by 2010 SSRS

wow, that is going to be a scary ride.

I sure hope so!

[Christiancoach]

I saw a gold 88GT for sale in someones yard today. I was so tempted to stop. When I owned an 86 I wanted so badly to do the V8 swap! I was young and had no money to do anything of the sort. I think my wife would kill me if I came home with it now.

[shank0668]

Nice, I have an 84, I wish I could do a swap, but no money considering im 14

[ALLTRBO]

It's coming along nicely...










The bottom half of the trunk was cut off at the factory ledge and re-welded to make room for the post-turbo exhaust and a rear diffuser.

[305pride]

this looks like fun

[ROD1]

Very cool and 600 HP? Holy chit mang! What will it weigh at completion? BTW I prefer the before pic but Im old school so .........

[305pride]

i like the before pic too

[ALLTRBO]

Originally Posted by ROD1

Very cool and 600 HP? Holy chit mang! What will it weigh at completion? BTW I prefer the before pic but Im old school so .........

It should weigh in right at 3000lbs or a tad over.
As for the 600whp, it'll be a good while before I get the shortblock built and the extra supporting mods, so please don't hold your breath. It's my long term project car. The initial setup should be mostly complete sometime this year. Hopefully I can hit 350whp safely and on 93 with the TGP bottom end.

I also like the before look (except the color), in particular I really like the VW 5-spoke wheels that I so thoroughly sought out in good condition for a low price, much better than the PS'd ASA AR1's in the next pic. The problem with the VW's is that
1) They're heavy (well, not compared to 5thgen Camaro wheels, but...)
2) The offset is too low for the front of the '88s, so they stick out a bit. That kills the good scrub radius, leverages more load onto the bearings and weight on the suspension action in general, and just kinda looks odd.

I'm going to run that combo anyway for a while, until I really figure out how it acts on the car, then I'll sell them for a new set (most likely the AR1's) that I can 'configure' to my liking. That should likely be 17x9's on the rear with a 38mm offset and 16x7's on the front with a 48mm offset.

The front bumper was just a quick photo-chop-off. Here's the new front bumper I'm going with in its prototype stages, by Rob's Fierovation (small one-man operation. He makes VERY good quality parts for Fieros and replica kit cars)...

Edit: Pics below.

It's based on a kit Ferrari 512TR nose, and I think it fits the styling of the Fiero perfectly, and there are definite performance benefits to it. I'll be modding it a bit further for even better airflow through the mouth, but I'm not sure exactly what I'm going to do yet. I'll cross that bridge...
I'm #4 in line for the production version.

The paint scheme, however, is staying. I really like it.

(For the record if it isn't obvious, this isn't my car)

[ALLTRBO]

Here's the PS of the car as is (minus brakes... which it now has), with only the paint job changed...