Fiero rally car build, Part II

[Chase Race]

My own racing has not been a priority for a couple years, so the project cars have been collecting dust and turning into shelves.

Step 1: excavate project cars and get the green car's ass end pointing towards the work area.





After that, the next item on the agenda is to remove the built-to-the-hilt-and-never-got-it-tuned-right motor from this car:



and replace it with a good running stock motor.

The race motor may get temporarily transplanted into my street Formula (you can just see the nose in the first photo) for tuning. I haven't worked out the details of that yet. Eventually the race motor will make it into here:



The green car will get sold, as will this car:





Why am I selling a perfectly good '88 GT rally car and building an '88 Formula rally car? Good question.

I bought the GT as you see it because it was too good of a deal to pass up and I hadn't figured out my ultimate plan yet. Eventually I decided that I wanted to build a car from the ground up, cage included, to showcase Chase Race.

I'll try to sell the '85 and the '88 together. Between them somebody could make a quite competitive '88 rally car.

Here's the '88 in a past life:





If anybody can offer some video editing help I'll post a 15 second video of the '85 in action.

Stay tuned...

[crzyone]

That last picture is wicked! :thumbleft:

[Shaun41178(2)]

what all was done to that built yet untuned engine?

[Chase Race]

what all was done to that built yet untuned engine?

Just your standard make-a-naturally-aspirated-motor-go-faster stuff:

10.25:1 compression
6" small block Chevy rods
roller rockers
big cam
porting
balancing
shitty stock exhaust manifolds

As it is it won't idle. Gotta keep your foot in it and hold it around 2000 rpm to keep it running. So I need to tune idle first. Fortunately it always starts well. It runs decent at WOT, but the dyno numbers were quite disappointing - somewhere in the high 130s at the wheel.

I place primary blame on the exhaust. I'm one of those folks that believes the stock exhaust manifolds are a big bottle neck on the V6. The last time I started working on the equal length headers I did an oil change and discovered metal in the oil. I tore the motor down and discovered a wiped out cam. Guess I didn't get it broken in right. So the headers got put on hold while I got a new cam and had the crank ground, and then after one more race the car got parked so I never got back to them.

I also think I may have too much cam for the long runner intake. So many things to do... Headers first, then tuning, then dyno, then see what I need to change next.

[Chase Race]

You can look into the Truelo intake, but I'd see $800 spent elseware, liking making your own custom intake. Plus that one doesn't fix the lower runners, with a custom manifold you can go from the head up.

I bet the intake manifolds, and exhaust manifolds are really holding you back.

I agree. Although I think the exhaust is a big bottleneck, I also think the intake is in the same ballpark. Especially when I want to turn some RPMs.

And I hate to say it, but I'm not a big fan of the Trueleo intake. I definitely appreciate the very real power gains, and the amount of work that goes into producing them. But as vain as it is, I'm not a big fan of how they look. I think I could make something that worked as well but was a little more elegant.

Unfortunately, the amount of work it would take does not fit in well with my immediate priorities, so I had a different idea. The reason the carb guys (like Oreif) get the highest hp numbers isn't because of the carburetor, it's because of the intake manifold. So how about adapting a GM TBI to the Edelbrock carb manifold and running it with a 7747 which is one of the best hacked ECMs around. This would also move the power up the RPM band from Trueleo. I'm betting I could top Oreif's 3.4 hp numbers with this 2.8. IF / when I get around to this project I'd be happy to bet a dyno session on it. Who has that motor now? Even if I lost, I think it would be fun to see what they both made when installed in cars. Comparing Oreif's engine numbers with some chassis numbers would also give us some actual data for driveline loss.

The other idea is to go with a little smaller (hydraulic this time) cam and optimize it for the RPM range of the intake. I think this would give me a very easy to drive power band, but it would have a lower hp number and would ultimately be slower in the race car than the TBI setup. And at the end of the day, the speed of the race car is the ultimate goal.

I have more ideas than I have time for so if somebody else does this first, I'd love to help. But you heard it here first. :thumbleft:

Oh, and the bet is only for my motor.

[Chase Race]

PS. I started it today. :thumbleft: It got my juices pumping about the project. Unfortunately (although not really) I have three customer cars and two other projects I need to get through the shop before I head to Minnesota for a rally crew gig next week. So that's as far as it gets for now.

[Standard]

Coming up here for the Ojibwe rally? Wish I could make it, but I've got other obligations already.

[Aaron]

I also do not like the Truelo intake. It is an EXTREMLEY expensive piece, that doesn't fix everything. Fact is, the lower manifold still sucks. It is like me with the DOHC, at first I was just going to do an upper, but then I thought straight, and realized that the problem is the ENTIRE piece, not just parts of it. It is almost a shortcut IMHO.

Also, I CANNOT stand how he uses a straight piece from the plenum to the throttle body, cut up and welded to make turns. Would it be that hard to buy 2.5" mandrel bent pieces off Ebay for $15 a pop? You'd save welds too!

[Pyrthian]

love the zip ties
like a stitched wound

:thumbleft:

[Chase Race]

Coming up here for the Ojibwe rally?

Yep. I'm crewing for the Hintz bros and then after the race I'm going to spend a couple days in Minneapolis visiting my sister.

[The Dark Side of Will]

Also, I CANNOT stand how he uses a straight peice from the plenum to the throttle body, cut up and welded to make turns. Would it be that hard to buy 2.5" mandrel bent pieces off Ebay for $15 a pop? You'd save welds too!

He DID. There's a new version out with updated TB neck.

[The Dark Side of Will]

The reason the carb guys (like Oreif) get the highest hp numbers isn't because of the carburetor, it's because of the intake manifold. So how about adapting a GM TBI to the Edelbrock carb manifold and running it with a 7747 which is one of the best hacked ECMs around.

I've been waiting for YEARS for someone to do this...

I'm betting I could top Oreif's 3.4 hp numbers with this 2.8. IF / when I get around to this project I'd be happy to bet a dyno session on it. Who has that motor now? Even if I lost, I think it would be fun to see what they both made when installed in cars. Comparing Oreif's engine numbers with some chassis numbers would also give us some actual data for driveline loss.

Oreif annoys the hell out of me every time he talks about his engine... and the way people worship it like it's the best ever... Come on people, it's 225 HP. Get real.
He'll also be MORE than happy to tell you conclusively exactly how much loss the Fiero manual transmission has, despite the fact that his car was dyno'd with an automatic.

[eHoward]

eh, TBI is like a compuer controlled carb. I'd rather see custom intakes with multipoint.

Actually, now that I've got the TIG, I could probably make a wicked aluminum intake.

The reason the carb guys (like Oreif) get the highest hp numbers isn't because of the carburetor, it's because of the intake manifold. So how about adapting a GM TBI to the Edelbrock carb manifold and running it with a 7747 which is one of the best hacked ECMs around.

I've been waiting for YEARS for someone to do this...
.

[Aaron]

The TBI throttle body itself isn't bad at all, it is that form of fuel injection that isn't great. Going SFI/MPFI with that throttle body though would make for a great setup!

[Chase Race]

I'd rather see custom intakes with multipoint.

Of course! So would I. But building a race car is a series of compromises, right?

Actually, now that I've got the TIG, I could probably make a wicked aluminum intake.

That would be cool. You should do it.

[The Dark Side of Will]

eh, TBI is like a compuer controlled carb. I'd rather see custom intakes with multipoint.

TBI, while far from great, is still fuel injection. It has the one characteristic that puts all EFI system light years ahead of carbeuretion... feedback via the oxygen sensor.
While it does have the disadvantages of a wet manifold, in this case that manifold is pretty much the best available for making power.

[Ultimate 85]

Totally love that "down to business" interior look. That cage is awsome.

[Chase Race]

TBI, while far from great, is still fuel injection. It has the one characteristic that puts all EFI system light years ahead of carbeuretion... feedback via the oxygen sensor.

While it does have the disadvantages of a wet manifold, in this case that manifold is pretty much the best available for making power.

Yes, on the dollar (and/or time) per horsepower scale this manifold ranks pretty well.

Another advantage EFI has over a carb in this situation is that it has a pressurized fuel system. This means you don't have fuel sloshing around in float bowls as you're bouncing down logging roads.

[Chase Race]

Step 1: excavate project cars and get the green car's ass end pointing towards the work area.

Progress!



I warned you this would be slow. Been busy.

[Aaron]

I never asked this before, but is a 2.8l, even built like the one you have, powerful enough to compete?

I'd expect some serious competition out there, and I wouldn't think 140whp would be enough to go anywhere.