I have a 91 rs with a lt1 383 i just put in and mostly stock speed density TPI. I put in a set of ls1 24lb injectors over the stock 22lbs a few weeks ago because it was all i could get my hands on at the time. I'm thinking of buying 28lbs or more but my main questions is what happens if i put 30lb injectors on my 383 car without tuning it?

I got a chip from a guy but got burned cause he made it for a carb'd car so it is just a stock ecm now and i've been doing my homework on learning to do that myself but there is a lot to learn.

the reason I ask is because i am overheating after about 25 minutes of driving no matter the road condition, temp, highway, whatever. I've done so much research and got a big champion rad, pump, stat, dual fan conversion, new hoses, radcap. i dont mean to make this post about overheating i am just stating that even tho my plugs look ok i think i am running lean still.

 

Can anybody tell me how the computer will react to 30lb injectors compared to the 22lb?

 

Im sure you spent alot of money building the engine . nows not the time to save money to protect your investment. Find someone local to tune your car live or learn yourself. Dynamic efi ebl p4 would save you a lot of time getting up to speed on the tune.

 

I would get an EBL P4 Flash...
Send in your ECM, and they will install it and send it back...
3 wires to change on ECM harness (I have poor vision, was legally blind) and I had no problem installing it / setting it up... Then you can tune it to what it needs...
Call SouthBay Injectors to get the right ones too...

http://www.dynamicefi.com/EBL_P4_Flash.php

http://www.southbayfuelinjectors.com/

I did both those things and I cannot believe how smooth my engine idles...

Overheating, be sure you are using an air dam just below the radiator, it makes a huge difference (even with the tuning ability of the EBL), with my car...

Rafael

 

The air dam is definitely good but doesn't do anything at idle, if he is overheating at idle then that means it's something else. What temp do your fans turn on? Dual fans should do the trick.. When was the last coolant flush? Ratio of water vs. prestone?

 

if a mod wants to move this thread to cooling that'd b great.

Air damn is great, I have the dual fans wired to stay on fulltime until I figure this out. They are successfully. Pulling a lot of air thru my rad as well so don't blame dirt and bugs. 160 stat, 180stat, no stat. Tested all 3 lol no change. Hoses don't kink. The rad flows, pulls from the overflow, no air pockets, 50/50 coolant with water wetter. I assumed the 24lb injectors wouldnt run lean 400-425 hp engine at idle or casual break in driving but I'm no expert at anything here.
So once it is up to operating temp I can drive it and keep the guage at 200-220 for the majority of 20-30 mins. Doesn't matter if I'm going 30mph in town no stops or 65 mph on the highway and after that period it takes less than 5 mins to hit 250 and I shut it down.

I'm in the process of making a shroud but u can just hold ur hand by the air dam and it is pulling air all over in there so idk how much that will change. Also I have been searching for a efi tuning professional in Iowa and no luck at the moment.

 

To respond to the dynamic efi advice. That really looks awesome, the price baffles me because that's more expensive than a top of the line Intel processor or nvidia graphics card or other high end electronics. I still need to know what injectors I require for this 383.

 

At that point I would recommend tuning it or getting a WB02 to see what's going on with your A/F ratio and if it's really lean or what.

 

Try a single fan setup like what's on a 85 TPI. I have no issues with mine. 160 stat, fan starts at 160, temp never gets over 200. I do have constant flow through the heater core.

 

The price baffles you lol? I think you have your facts wrong. Any idea what an XFI, FAST Classic, Holley HP, BS3, or even Megasquirt with the correct add-ons costs? My Grand National buddies spend over $1500 on their XFI units, and they still have to wire it all in to the stock harness. My EBL-P4 does everything their XFI can do, and it hooks up to my stock harness, for one third of the price. It astonishes me how members on this board want to nickel and dime their builds, but then pay for it anyway in the long run. Good luck...

 

Honestly I'd go with 36lb injectors man, they're good for 500 crank horse power. Get the Bosch 3 style.