Hey guys,
I have a '93 LT1/M29 T56 and 12 bolt with 3.31 positraction in a '72 hatchback Vega. I am running 16" IROC-Z wheels at all four corners with 225 50 16 up front and 245 50 16 in the rear.

Right now my motor is stock, other than a BBK 58mm throttle body, complete smog delete (including EGR) and Sanderson 1 5/8" headers. I don't run any accessories on the motor, just a low mount Alan Grove Motorsports alternator. My exhaust is 2.5" true duals into Flowmaster 40s with an h-pipe.

As it is right now the car breaks traction real bad anything over quarter throttle in first gear, pretty much anywhere I hammer it in second (or even quickshift into second and pedal it), and when I quickshift into third I have to pedal it a bit.

I'm looking for a cam that will raise the powerband a bit. Being that my car is a six speed I don't mind losing some drivability. In fact, losing some low-end torque will actually help my traction problems. I've been considering a CC503 but is there another cam that would suit my needs? My heads and intake are unported but that's my next mod. I'll be sending my heads and intake to Lloyd Elliot later this summer. My horsepower goal with heads/cam/intake is around 400-420. I don't think I'll need any more than that to get into the 11s.

Does anyone have a recommendation? I'll be doing most of the tuning myself as I have a Moates AutoProm. I don't intend to rev it more than six grand. No need when the car only weighs about 2500#, anyway.

Thanks,
Colin

 

Very nice. I almost traded my 87 GN for a 72 215 V8 Vega back in '91. It was the first Vega I saw with IROC wheels.

Since you are having the heads sent to LE, have him recommend a cam. It'll be exactly what you want based off the info you give him.

Good luck, great little setup.

 

So you choose heads to go with later but are trying to get an off the shelf cam first. Off the shelf cam and those heads is unlikely to get you your power goal, your absurdly low self imposed rev limit is going to stop you from hitting your power goal.

The cam would have to be a really crappy design to compromise lowend torque but still like being kept below 6000rpms.

400rwhp should put a car that light way down into the 10s. I use very good parts that make great lowend, probably somewhere in the 400-420rwhp range and it puts my over 4 ton boat of a car into the mid 11s, a good part of that is the launch though. With proper parts selection I have a cam still making great power at 7000rpm but still lifting the nose of the car and running 1.5 short times. With the low rpms we turn a big lowend torque loss signifies poor quality parts or tuning.

If I were you I would probably do the 503 cam, rockers and springs, turn it the 63-6400rpms it will likely want with stock heads and put the rest of the money into the suspension rather than heads. Should easily get into the 11s like that.

If you give it some more gear you might find it easier to regain traction, with the T56 4.10s are a nice fit, in such a light car you could try 3.73s.

If you still want to lose lowend I would just dial back some lowend timing, like I said, a good cam with the low rpms we turn and you can't really lose much lowend unless there is a problem.

 

Thanks for the replies, guys. I didn't know an LT1 wanted so many revs. My experience up until this point (besides my '04 GTO that I recently sold) was with IROCs and I think they quit about 5500.

I think I'll go with the 503 and the other associated goodies. I'll have some fun tuning it and then make the jump to a LE setup a bit down the road.

Recently, Spohn Engineering came out with some stuff for the Vega. I was one of the first people to purchase their adjustable upper and lower rear control arms (my car has a 4 link). He's supposed to have a set of adjustable upper and lower front arms coming out soon, too. As well, I'm having some wheel hop issues but I'm not sure it isn't my spring rates. I'm 280lb and when I sit on the car it doesn't drop more than half an inch. Whatever I have in the car makes it awesome to corner, though. It smokes my old GTO and smashes on my IROCs. And I want to do a big brake upgrade front and rear.

Thanks again and awesome suggestion about modifying my timing. That's easy to do with the AutoProm. I hadn't even considered that.

 

My suggestion would normally be to put more tire on it, rather than reduce the power. But it doesn't look like there's much room for tires. Are you at least running a sticky drag radial, or are they street tires?

Time to tub it.

 

Injuneer,
Haha... you are very true about it needing wider shoes. I have two boys and I don't want to tub it. Doing that will ensure I'll never get to cruise with them. Currently, the tires rub a smidge when cornering but I haven't figured out how much side to side movement a 4 link is supposed to have. I don't hear the rubbing in a straight line so I just take low speed corners more slowly.

Here's a picture of from the rear showing that I will definitely look like a redneck if I go any wider. One issue for sure is that the tires are very old and nearly bald. A set of high performance, sticker tires will definitely help but hey...2500 pound car and big horsepower does a lot of smoke make.

I'm sure it would be quite a bit faster than it is now if I wasn't scared to hammer on it off the line. It wheelhops pretty bad so I have to roll into it but if I hammer on it in 1st or 2nd it just lights the tires up. Kinda fun, though.