New Dyno Results for the old E Prod Racer, now NASA PT-A

[E Prod Racer]

Been experimenting with E85 on my race engine, and today right before loading onto the trailer for the NASA weekend at High Plain Raceway in Byers, Colorado, my DynoJet says: 174.23 WHP, 135.46 WTQ. Typical loss for front engine rear drive live axle is 15%, so the numbers for crank with that loss would be 204.98 HP, 159.36 TQ.

The car was recently taken off of FireBreathingFiats.com, so if you aren't familiar, this is a NASA PT-A (EX SCCA EP) 1969 124 Spider 2.0, with Croft/Shadetree 13:1 pistons, Croft 5A, 4A cams, Shadetree head with 46mm inlet and 40mm exhaust valves, 48IDFs with 42mm venturis, on a ported waffle mani. Engine drives an FF2000 QuarterMaster clutch on a lightened steel flywheel, into a 131 gearbox with Abarth shift extension. Rear is the worked over mid years FIAT unit with equal length 3-link located by a Clemente/MAC designed wishbone locator link.

I will be posting pictures if anyone is interested.

[sptcoupe]

Nice work! Sounds like it will be very competitive. Please do post some pics.

[mdrburchette]

Very nice, Bill. It looks like NASA gives you a little more wiggle room in the carb category than SCCA. Please do post pics. I'd love to see the 3 link rear suspension.

[ital]

The car was recently taken off of FireBreathingFiats.com,

Hi Bill, your great car was taken off not because it wasn't worthy of being there any more! I want to create an exclusive web site dedicated totally to the 124 coupes.

There are so many other spider web sites, books and written material about them out there enough to eat and drink Fiat spider all day.

It's time to give the 124 coupe the respect it deserves and all the exposure.

[Redline]

Hi Bill, your great car was taken off not because it wasn't worthy of being there any more! I want to create an exclusive web site dedicated totally to the 124 coupes.

Great idea. Please let us know when it's up and running.

[wmausbach]

Bill,
Please post pictures. I saw/photographed your car when you made TWS (Texas World Speedway) race back about six years ago. I would like to see the updates as (correct me if I'm wrong) but under SCCA you were limed to stock vales and 34mm choke on 40 IDF's. I curious what did your engine dyno before under E-Prod rules? Sounds like you made a quantum leap !!
Thanks
Wayne in Houston

[sptcoupe]

Bill - What kind of ignition advance are you running? And what did you use for the intake manifold?

[E Prod Racer]

Sorry about the delay in getting back. I am working with my web host to figure out why I can't get new pictures up on the macautosport.com Gallery section. Maybe as soon as tonite.

I will have to search out the pictures I have of the rear suspension - it really is very slick. At the limit of adhesion, the stock suspension on a Spider will take you on a nasty ride, as it binds up - partly the unequal length trailing arms, and partly the Panhard bar.

The wheel HP in SCCA EP trim was about 150-153, so a really good pickup in HP due to the bigger valves, and the big IDFs. I discovered a good place to get IDFs at http://www.thesamba.com which is a VW Sandrail trading site. They always have 40s, 44s and 48s for sale. I also found JayBee MFG. from than site. They sell custom venturis, and jetting for the IDFs. As far as tuning is concerned, I'm not entirely finished, as I have some cam timing adjustment to make, and some more work with maximum advance. I ran the engine with 36 to 38 degrees max advance on 110 leaded race gasoline, but since switching to E85, I have set the advance at 41 degrees max advance for now, but will try for more (42-43) to see if there is more power on tap. The Ignition is Electromotive HPV-1 crankfire, which is very easy to set for advance. It uses pots to set initial advance, verified by a voltmeter, and advance over 3000 rpm, and 8000 rpm (turned off). So, max advance is achieved at 3000 rpm to redline, which is 7500. The engine will freely rev to 8000 and beyond, but I keep it strictly to 8000 (watch the tach!!). There is a rev limiter, but it has been known to wander, so a sharp eye on the tach is what I use. The power band is 4500 to 7500 rpm, which works with the gearbox ratios on all of the tracks turns I encounter. The pickup from gear to gear is very strong at 4500 to 6500 ft elevation. I'm wanting to get the car out at a lower elevation to really see some power.

[E Prod Racer]

Finally, pictures.
http://www.macautosport.com/index.php?o ... itemId=956

More to follow. I will post up the rear suspension, pictures of the head and manifold with the 46mm inlet and 40mm exhaust valves, and any other details requested. Let me know.

[mdrburchette]

Who designed your header, Bill?

[carl55]

Very nice
Interesting headers and overflow bottle.

Carl

[sptcoupe]

Looks great! How much does it weigh? You'll likely have to rejet the carbs when you get it down where there is some air for it to breath. I owuld be really curious to see what the HP difference is at normal altitudes!

[baltobernie]

Wow, what a strong-looking car! Thanks for the pictures; can't wait to see the internals. Maybe post the dyno run results so we could see the shape of the power curve?

[htchevyii]

Wow, that looks tough with the flared body!

[E Prod Racer]

Denise, the header was designed by a guy named "Bob", who builds headers for ShadeTree Enginetrics in Nevada TX. Robert Rodgers is the owner, call (972) 843-8134. They are a "stepped" design, with 1-5/8" primaries from the head out 6", transitioning to 1-3/4'", with total length of 29 inches each runner to 4:1 collector with 2.5" exit. a 48" exhaust pipe in 2.25 or 2.5" completes the exhaust. Note is loud and, as someone described "raunchy". About 100db @ 50'

The weight with no fuel is under 1800 lbs. Racing weight is, well, more with me in it. Not a flyweight, I'm afraid. The overflow is an old Moroso unit, and is pressurized. combined with the larger copper radiator, the car runs without any fan, and stays in the 200 to 210 range most of the time - have to keep moving to stay cool.

The body was made by the Baucoms, actually by Japco from their molds. I modified the front to allow a removable airdam to make it easier to get on and off the trailer. Picture to follow. Still working on shots of the rear suspension, and will include the front suspension. I certainly don't mind any of you getting any ideas for a competition FIAT Spider. This one work really good, and more of them in competition would not be a bad thing at all.

I'll see if I can get my tuner to save a dyno run file in .pdf form and post it. Looks really wierd, as there isn't much power below 4000 rpm, but it goes up rapidly beyond that engine speed. The torque stays very flat in the power band (5000 to 7500). Air/Fuel goes from off the chart rich to about 13.5:1 at WOT. Main jets are now 190s on the 48 IDFs. I would need at least 2-3 sizes larger for low elevations - E85 make for very thirsty, but a very cool fuel.

I'll take and post more pictures.