Lemons car - Turbo or TBI?

[Jeremiah]

Hello all,

Gonna be looking into a 24 Hr of LeMons build. My first question is which body you guys would start out with.. (L, G, P, etc) I understand that a lot of these unibody cars are kinda flimsy, but the 8 point cage should stiffen them up a bit.

Second and main question is, which would you guys prefer? TBI or turbo? Obviosuly the turbo will have a stronger pull out of corners and on the straight-aways, but will there be an issue of overheating the engine/turbo on such a long, continous race? I would imagine the 4th cylinder cooling mod would be helpful.

I would love to hear what you guys think about building a TM LeMons car :thumb:

[Rrider]

Look at the name of the forum.. turbo of course! Would they penalize you for the turbo though? I heard they do that.

[bfarroo]

If the car has a proper tune and a good radiator there should be no issue with a turbo car. They will drink a lot more fuel though so you'll probably have more pit stops for fuel. A set of PT lifters is a must for any sustained high rpm driving.

[shackwrrr]

Turbo, add oil cooler and accumulator, keep boost stock but add intercooler. Nothing to increase power, only durability mods.

I would go 89 up 2.5 turbo, garret turbo, add intercooler, oil cooler, and accumulator. PT lifters, synthetic oil, add extra capacity to oil pan, Exhaust evac system, and any other cheap stuff to increase engine durability.

[turismolover22]

Well if he goes 2.5 and removes the balance shafts, he has an extra quart of space for oil in that pan. Id also add to that list a windage tray and crank scraper. Consider porting the water pump and oil pump port at the block. Little things that free up a couple hp and reduce the load on the engine, while benefiting cooling and oil delivery.

[Vigo]

Well, i'll be the dissenting opinion and say that i'd rather run a TBI. Lemons in general is mostly about finishing the most laps before breaking, with winning being something that only the surviving cars are eligible for. Turbo dodge 2.2/2.5s have not had great durability in lemons up to now, and i think most of it has to do with heat build up.

I think Shackwrr has the right approach, though. Your absolute top priority should be an oil accumulator, followed by an oil cooler, followed by adding even more oil capacity. The engine's survival is basically all down to oil pressure and temperature. Overheating (of the coolant/top end of the motor) is basically not an issue on a TBI with a good working cooling system. It can be an issue on a turbo car, but if you restrain yourself to stock boost levels like Shackwrr mentioned, it shouldnt be too much of a problem.

[tryingbe]

Reliability is #1.

Spend your $500 towards that first.

If you have left over, then for speed.

[Ondonti]

Run a 3.3 and make Vigo happy

[Pat]

I'd go tbi. Fast cars don't win lemons. Cars that stay cool and stay running do.

[Jeremiah]

I'd go tbi. Fast cars don't win lemons. Cars that stay cool and stay running do.

This is what I was thinking. I don't think a turbocharger would be as useful as N/A with some upgraded cooling mods..


Anybody have any tips/ideas for keeping the engine/head/brakes cool?

I've thought about the 4th cylinder coolant mod, maybe ducting air to the brakes somehow? I've heard some racers experience their brakes essentially melting after a few rigorous hours.

Thanks guys!

[bfarroo]

Using the larger 11 inch brakes will help with good racing pads. Ducting if at all possible will help. When racing my 88 shadow I went through a set of pads in 300 miles.

[glhs399]

I have had fairly good luck with the CSX that I have ran in the Chump Car races. Here is the recipe that has been working fine for me.

Low boost (under 15 PSI)
3 qt accusump
RX-7 oil cooler
Baffled oil pan
Starion intercooler with 2.5" inlet and outlet pipes welded on
Roller cam with PT Lifters
Exhaust evac setup with catch can
Large radiator out of a automatic car
#4 coolant mod
11" brakes

Oil and water temps stay good. I have had issues with the outer cv, clutch exploded, rockers flung out (slider setup), aluminum crank pulley broke.

Car will be plenty quick enough at 12-15 PSI to pass the fast cars on the track. I would say pick the lightest car you can to build. Keep it simple, the power from the turbo makes more fun but more parts to fail and more wear (brakes,fuel,tires.) A lot of time can be made up increasing you corner exit speeds depending on how long the straight sections of the track are. I might consider running a Flex fuel N/A setup to get rid of the tbi setup. Like everyone else has said spend time on building a reliable drivetrain and don't worry about the power. Next I would work on brakes suspension. I have had a lot of success racing the CSX in the wet but I still haven't spent the time to make the car quicker in the dry.

Good luck and have fun and keep us updated