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JohnInKansas
JohnInKansas Reader
4/30/12 1:22 p.m.

... to make a Fiat 850 fast? I have a line on a free, running example that's too ratty to be useful as a street car, but might be ChumpCar/Lemons material...

Engine swap is possible, but most of what I've read about swapping into an 850 is that the ratio of available power/torque:handling-characteristics is manageable in stock form, but if you change the weight distribution or power output or both, the car becomes a pucker-generator pretty quickly.

Would rather not change suspension too much. Would consider changing to mid-engine if that wouldn't screw the handling/weight distribution (see above).

GameboyRMH
GameboyRMH GRM+ Memberand UberDork
4/30/12 1:24 p.m.

'Busa swap plus wide tires and a good grip on the wheel!

MG Bryan
MG Bryan SuperDork
4/30/12 1:26 p.m.

Ditchdigger's is pretty berkeleying cool - http://grassrootsmotorsports.com/reader-rides/820/

He might be your best bet if you want serious information on them.

JohnInKansas
JohnInKansas Reader
4/30/12 1:33 p.m.

I'll have to check on eligibility of motorcycle engines in ChumpCar. Dunno if that's kosher. If so, that's certainly a possibility. Not sure how that kind of power would adversely affect the rest of the car...

I've seen Ditch's build threads somewhere, lots of good information. I don't know about turbocharging; turbos tend to grenade at crapcan endurance races...

50eggs has an 850 racecar... if he doesn't chime in soonish, I'll go dig up what he was planning for his drivetrain...

Vigo
Vigo SuperDork
4/30/12 1:39 p.m.

my brain's cliffnotes of your post:

  1. I am going to take a tiny, ancient car, and race it around alongside a bunch of disposable and generally much heavier cars.

  2. i acknowledge that making this thing entertaining enough to race means part #1 becomes EVEN LESS safe.

  3. I dont want to do mild work messing with the suspension to make it a viable road course car, unless i am doing massive major work completely changing every damn thing to make it mid engine.

Im not against it, i just think this is pretty hilarious. Watching and waiting.

JohnInKansas
JohnInKansas Reader
4/30/12 1:54 p.m.

In reply to Vigo:

Fair enough, especially on #3.

The reason I shy away from suspension changes is the 850's suspension setup is not one you see on performance cars. Front is single a-arms on either side with single transverse leaf spring at bottom of kingpin. Rear is trailing arms and coil springs.

I suspect that if I wanted it to be really nice in the corners, I'd... well, I'd have the sense to go with a car with a more conventional suspension setup.

The mid-engined conversion (I think) could pass as part of an "engineering theme", which would make conversion expenses exempt from the $500 Chumpcar value. It would be MUCH easier to not change the configuration, granted. I like to throw some wild ideas around though, gets people thinking. Or laughing, as the case may be.

ditchdigger
ditchdigger Dork
5/3/12 2:07 p.m.

Don't know how I missed this thread.

You would be surprised how well an 850 can handle. They have always been praised for their nimble handling. They are very entertaining cars to drive. They tend towards understeer but respond to lift throttle to change that, but not in a violent 911 like manner.

IIRC this car is still on leaf front suspension. http://www.youtube.com/watch?v=AwZsYE6zl_Y http://www.youtube.com/watch?v=UtJ9DaDyVmA&feature=relmfu

Making power is the tough part. I did the 903cc with big cam, high compression big carb thing and managed to pull 48hp on the dyno. It was fun but still 10 seconds to 60mph in the sedan body that weighs 200lbs less than the spider. Boost is great and the little motors seem to laugh at 15psi.

For a lemons or chump car bolt a VW bug trans in the back and then fit the lightest motor you can. I doubt there is enough room to go longitudinal mid engine like a 914. Perhaps a fwd drivetrain like Nash's 600?

Curb weight when new was in the 1575lbs and I bet stripped out you could be seeing under 1400 so 100hp should make for a lot of fun. 150hp would be crazy!

The real question however is the shell solid enough to use? These things rust like....well.... an italian car. It is pretty much a guarantee that the X brace underneath the car is rotting and once that happens they tend to fall apart when jacked up in the middle. If it is solid it would be a bit of a shame to see another cool car destroyed in the name of Lemons.

My dream motor would be the goldwing flat 6 but that is a heavy sucker.

M030
M030 HalfDork
5/3/12 3:10 p.m.

Mazda rotary?

JohnInKansas
JohnInKansas Reader
5/3/12 4:52 p.m.

I'd like to be around 12lb/hp (give or take 2), if possible.

I think, Ditch, that you suggested a VW transaxle in another 850-related thread; I haven't found it yet, but I guess it is possible to swing the bellhousing around to the front and still retain 4 forward gears (rather than 4 reverse gears)?

Assuming VW transaxle, how would one mount a motorcycle powerplant to it? You could run the transaxle with just one gear; just use it as a differential with the motorcycle transmission for gearing. You could lose the bike tranny and run a driveshaft to the transaxle. Could you mount the engine (sans transmission) to the transaxle with no driveshaft (gear-driven or chain driven)?

Rotary had crossed my mind, but for some reason I have a preexisting notion that flogging a rotary around a racetrack for 10+ hours a weekend would result in reliability issues... though that's probably a given with ANY engine...

Back to Ditch: The X-brace IS a bit soft, but not terminal. You can still get patch parts to repair them; I think they come in 4 pieces, weld in type. We looked at that, and I think decided that we'd need one of the four patches. The outside isn't real rusted out, but the floorboards, rockers, and trunk floor are. Body has several hundred noticable door dings as well (no big dents, but LOTS of little ones). This isn't a great candidate for restoration.

The stock engine runs well. Rebuilt not long ago.

93EXCivic
93EXCivic UltimaDork
5/3/12 5:18 p.m.
JohnInKansas wrote: Assuming VW transaxle, how would one mount a motorcycle powerplant to it? You could run the transaxle with just one gear; just use it as a differential with the motorcycle transmission for gearing. You could lose the bike tranny and run a driveshaft to the transaxle. Could you mount the engine (sans transmission) to the transaxle with no driveshaft (gear-driven or chain driven)?

I think your only really choices as far as motorcycle engines are HD V-twin or Moto Guzzi V-twin since those both use separate gearboxes unlike most motorbikes. I have seen a Morgan 3-wheeler replica that uses a Moto Guzzi V-twin mounted to a Beetle transmission.

Curmudgeon
Curmudgeon MegaDork
5/3/12 6:16 p.m.

I'd not try to do the motorcycle engine thing. Too much to go wrong.

My brother had an 850 Spider. IIRC there was just not a lot of room anywhere in that car, so a VW transaxle with a Type 3 or 4 engine (~85-100 HP without running a overstressed Type 1 case set) would be entertaining without reinventing the wheel. The transaxle is easy to make mid motor, you flip the differential over in the case. Not as hard as it sounds. But the VW engine is wide and there is just not much room in there.

If you are still dead set on a midmotor, I'd suggest a Chevy Sprint Turbo setup. The turbo 3 banger will be a lot easier to cram in there and should still make it very fun. Maybe some of our Canuck brethren can come up with a Pontiac Firefly powerplant.

icaneat50eggs
icaneat50eggs Reader
5/3/12 7:02 p.m.

This discussion has depressed the hell out of me.

I don't know if it's possible to make a race car out of one

However that doesn't mean I'm Not trying

However the suspension has already had a major redo by the previous owner

When you said there isn't much room I'm assume you meant for a mid engine setup, because the rear end swallowed a subi ej20 easily

SVreX
SVreX UltimaDork
5/3/12 7:32 p.m.

Your willingness to swap to mid-engine without doing suspension mods is amusingly short sighted.

Moving the engine to the middle IS a suspension mod.

The weight distribution would change so drastically that the dynamics at every corner would be completely different, not to mention chopping the floorpan on a car that has very little metal in it in the first place will also have a significant impact on the suspension and cornering performance.

If you are committed to the idea that you will make big changes such as this without modifying the suspension, don't bother. It will be a dog.

It's the intellectual equivalent of doubling the horsepower of a car without making any changes to it's braking capability.

However, if you ARE prepared to consider the suspension as part of the overall project, there is always plenty of opportunity for the creative mind.

Who says a suspension upgrade would have to mean a swap to an A-arm (or other) design?

The rear of my Yugo has a transverse leaf design. It wasn't hard to stiffen the springs, lower the mounting points, and add a leaf to the spring for a completely different attitude. It didn't involve welding or drastic engineering or re-design. It involved recognizing the car's usage had changed, and making the modifications necessary to address the changes.

djsilver
djsilver New Reader
5/3/12 8:52 p.m.

I really liked the look of the 850 spider when I was school age but all I've ever heard about these is that they are really easy to roll over. Maybe limiting straps are the trick? I saw an old Triumph with swing axles drop a rear tire off the pavement at an autocross and roll right over. It was a concours example of a rare version that was driven from the midwest down to Jekyll Island. It didn't get driven back....,

Trans_Maro
Trans_Maro SuperDork
5/3/12 9:08 p.m.

Look really hard for rust.

My 850 nearly broke in half because of it.

If the doors are hard to get shut properly, run away fast.

It's the only thing I've owned that rusted worse than '70s Japanese cars. I think you could hear it fizzing on a damp night.

Shawn

HiTempguy
HiTempguy SuperDork
5/3/12 9:51 p.m.
JohnInKansas wrote: The mid-engined conversion (I think) could pass as part of an "engineering theme

You think wrong. The engineering theme does not work like that, I actually read the exact line you are quoting in the rules at noon and studied it thoroughly.

Now, the performance value of the 850 in this situation is so abysmal that they might just value the motor as the cars worth, as Chumpcar says their judges have the ability to do.

I really like the 3 cylinder metro idea. I bet AIV on a metro motor with a 3-Tech (our own Zombie Woof) head/cam package (higher compression as well?) would make more than 48whp...

Knurled
Knurled GRM+ Memberand Dork
5/3/12 10:38 p.m.
JohnInKansas wrote: ... to make a Fiat 850 fast? I have a line on a free, running example that's too ratty to be useful as a street car, but might be ChumpCar/Lemons material...

I'll leave this here.

icaneat50eggs
icaneat50eggs Reader
5/3/12 10:47 p.m.

wow, that's inspiration!

JohnInKansas
JohnInKansas Reader
5/3/12 10:53 p.m.

AHA. THERE are the responses I was looking for.

Curmudgeon- You're probably right about the bike engine. LOTS to go wrong. There isn't a LOT of space in the car, but if the fuel tank was relocated, it would free up some space. Not much, but some. Complete VW drivetrain might be doable... wouldn't have to go mid-engined. I'm not stuck on a midengined setup. I acknowledge that changing the engine location tweaks with how the car was designed, and at that point, all bets are off. Chevy Sprint sounds interesting, though not as powerful as I'd like...

50eggs- Sorry to depress you. Subaru... with a VW transaxle... RR config...

SVreX- I hear you. What I'm trying to avoid is "upgrading" by adding lots of aftermarket parts. More aftermarket means more penalty laps. I enjoy creative thinking, but right now, there are more options than I am able to consider, so I'm bench racing. And brakes are a whole 'nuther subject...

Silver- I don't know about Fiats "jacking". I know a couple iterations of the Triumph Spitfire were known to jack pretty spectacularly in the rear, probably what you saw. Anybody know if the Fiat does this?

Trans- Its rusty, but not THAT rusty.

HiTemp- Okay. I'll take your word for it. If it ain't engineering, it ain't engineering. The performance value IS abysmal, valuing the engine alone is what I'd be building toward. Wiki has the turbo'ed Metro 3-cyl at 73hp and 115ft lbs. If nothing else, parts wouldn't be too tough to come by.

EDIT to add: Knurled- I had seen that, very impressive. Not sure all that's within my budget for Chump. Not sure how well that kind of setup would hold together in an enduro either... That may be another vote for VW power though.

/edit.

Keep coaching me, fellas. I'm not set on any one idea yet, so I'm very open to advice and suggestions. Thanks for the thoughts so far.

Trans_Maro
Trans_Maro SuperDork
5/3/12 11:38 p.m.

Look into the Z-bar for the rear suspension, it's supposed to control the swing-axle suspension pretty well.

These guys might be able to help you out a bit: http://www.mirafiori.com/

PBS makes some killer race parts but they are probably out of the budget and exceed the value of the car: http://www.scuderiatopolino.com/generalcatalog.php

Shawn

ditchdigger
ditchdigger Dork
5/4/12 12:26 a.m.

Once you lower and decamber the rear they no longer have the "very real" tendency to jack and flip. A limiting strap would be all that I would worry about installing. I beat on my car hard and never bothered with them though. Shortened shocks limit droop enough for me.

Some 850 coupes jacking and flipping in this video http://www.youtube.com/watch?v=0xwc54G2Ur8

icaneat50eggs
icaneat50eggs Reader
5/4/12 6:58 a.m.

oh, I have a porsche 915 trans instead of the VW

JohnInKansas
JohnInKansas Reader
5/4/12 8:50 a.m.

Okay, I'm still thinking.

VW Type4 with MegaSquirt; maybe turbocharged, though NA would probably make more power than is really necessary. VW or Porsche transaxle. Limit rear suspension travel, make suspension tweaks as required to keep the handling manageable.

Haven't looked at brakes yet, but plan to this weekend, see what's available.

Raze
Raze SuperDork
5/4/12 8:57 a.m.

Oh my, I'm excited to see where this thread leads...

Raze
Raze SuperDork
5/4/12 8:57 a.m.

Oh my, I'm excited to see where this thread leads...

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