injector size question

[Project 77]

I picked up a 93 Cobra that at one point had a Paxton Novi2000, with 42 pound injectors. The blower is no longer on the car, but the 42's and C&L meter are still on the car. I know the car runs rich, I got a sample tube to put in the meter for 24's and i'm waiting on my 24's to come via the mail. My question is would running that rich cause the car to overheat? It has a griffin alum rad., but if i sit for more than a few minutes the heat slowly creeps up until I turn the electric fan on.

 

[Wallzy]

"My question is would running that rich cause the car to overheat?"

No.

- If you sit without your fan on you are probably going to overheat, unless it is pretty cool out that day.

Walz

 

[stykthyn]

I dont think that would cause the car to overheat, but I am sure that your plugs are well on their way to being fouled. I would change those out and run some seafoam through the car.

 

[5spd GT]

If you have no airflow over the radiator, whether it be by you cruising at 25+ mph or by a fan, it is going to overheat.

The injectors are not the problem, and swapping to 24 lb injectors is good, and those are the factory injectors on the '93 Cobra.

 

[Project 77]

I always wondered if that seafoam stuff worked...can I run 10 PSI of boost with 24's through a stock Cobra motor??

 

[5spd GT]

The 42 pound injectors would be much safer for 10 lbs of boost.

Seafoam really does not do much at all. A buddy and I tried it on his 00 GT. It did not doing anything noticeable.

 

[chevyfan1]

how can i tell what lbs my injectors are by looking at them

 

[PUNISHER RACING]

orange 19, blue 24, red 30, dark blue 36, green 42

 

[5spd GT]

Fuel Injector Selection:

Injector HP Ratings: divide flow rating by .5 and multiply the result by the number of injectors. The following examples use a 100% duty cycle. These ratings are for N/A engines at the flywheel.

Example:

19 lb injectors/.5 = 38 - 38 x 8 = 304 HP
24 lb injectors/.5 = 48 - 48 x 8 = 384 HP
30 lb injectors/.5 = 60 - 60 x 8 = 480 HP
36 lb injectors/.5 = 72 - 72 x 8 = 576 HP
42 lb injectors/.5 = 84 - 84 x 8 = 672 HP

The preferred duty cycle is about 85% maximum, so for a safety factor multiply the final figure times .85.

304 HP x .85 = 258 HP for 19lb injectors
385 HP x .85 = 326 HP for 24lb injectors
480 HP x .85 = 408 HP for 30lb injectors
576 HP x .85 = 490 HP for 36lb injectors
672 HP x .85 = 571 HP for 42lb injectors

Remember that the above ratings are at 39 PSI. Increasing the pressure will effectively increase the flow rating. Example: a 19 lb injector will flow 24 lbs at 63 PSI, and a 24 lb injector will flow 30 lbs at 63 PSI.

See http://users.erols.com/srweiss/ to get the calculators used in these examples.

The above information is courtesy of jrichker!