Does anyone know the specifications of the EEC for a 92 F-150 or Bronco in relation to RPMs?? With this new motor I got I wanna see what it'll do, but I can't get over 3,100 RPMs in OD. This motor is built to do around 9,000 RPMs, and I kind of just want to see how fast it will go. I'm sure someone will mention TWEECER and a new EEC, but that's a ways on down the road.

Thanks

 

You have eec-iv. So does my '91(bone stock) it's neither rev nor speed limited. In other words I think you have a problem that can only be fixed once you do upgrade the electronics. What you may be experiencing is the ecm is reading the actual parameters before it thinks it's supposed to. Engine specs and parameters are programed from the factory into the ecm and the ecm uses those parameters to control how the engine runs. You may only find out what it'll do when you get finished with your upgrades!!?!!

 

I have a 92 bronco 302 Auto Eddie Bauer and it will rev to near 5000 rpm if you hold it in a lower gear.

What speed are you doing at 3100 in OD? at 70mph mine only does 1800 rpm in OD so you must be going like a rocket to be doing 3100 rpm!

 

so your trying to drive the motor running the stock speed density efi. there is a reason it wont rev higher because the computer doesnt know what to do with it. your also running a risk of the motor burning up. I would get a lightning ecu and at least take it down to a dyno shop for a tune. we cant help ya otherwise

is your exhaust still stock by chance? stock cat etc..

 

Hey Kem,

If I've understood you correctly the SD motors only have an ECU map up to so many RPM (c. 3000)? After that they just use fixed figures rather than adaptive to the conditions.

That does make some sense as under normal conditions my 302 is hardly a race engine!

Simon

 

these trucks rarly see anything above 4000rpms except when shifting. all power is produced down low in the rpm range as it should. this guy is running a modified motor with a cam not suited for speed density and larger injectors and asks why its not performing as it should. I tried explaining this awhile back when he first posted but got now where. I am sure he payed a pretty penny for this motor so you would think he would want it operating properly not half assd.

 

Cheers Kem. That all makes perfect sense. It always amuses me how low they rev when cruising. Its almost like a diesel motor with such a small rev range.

 

I'm not saying that the engine isn't running as it should, I just want to know if there's any way to get more out of it where I stand now. I understand that a lightning eec and a tweecer are a MUST, as well as larger injectors, but I don't just have an extra $200 to $400 bucks laying around right now. The exhaust is longtube headers going into a dual in single out cat. The single out part sucks, but that's what happens when you let your brother take it to get new exhaust I guess. As for how fast I'm going at 3,100 RPMs, I don't have a clue, the speedometer maxes out at 90. I'm gonna use a GPS to find the definite speed.

Kemical, I hate to see you get bitter at me, you've helped me a lot in the past few years. I just want to get the most out of what I have right now. I understand the necessities of getting optimal performance out of this engine, I just don't have that money to get that right now. As for the cam, I know it's not ideal for SD, but it really doesn't run that bad. The idle is higher than preferred, about 1100, but that's the only problem I've had so far. And I'm certain that it's high because the EEC is trying to compensate for the vacuum fluctuation.

Sorry for the long post, but thanks a lot to all especially kem, he's like our new greystreak.

 

90+ in a bronco must be quite scary! LOL

 

im not bitter, i just dont want your hard earned money burn up ya know.

what gears are you running and tire size again? Im wondering if anyone with DesktopDyno can put in the specs your running to see where the power is made in the rpm range of that motor. if that motor can rev to 9g that concerns me as to where it actually makes power and may be part of the issue here.

 

Kem is right, if you've got alot of money into your engine, and you're running it excessively lean, which you almost certainly are with a stock efi setup, you are going to fry your new engine pretty fast. It would be a shame to destroy a brand new high po engine.

 

Gears are stock 3.55 and tires are 32x11.50. I'm kind of glad you asked kem, because that's one thing that I've thought about a few times. I know with those gears I can't expect much top end, but I don't really want to go lower towards 3 or even 2s because I'll lose decent cruising RPMs. I hate to be one of those guys who turns their bronco into a hotrod instead of a 4wheeler, but it looks like I might have to make a choice between the 2. Either way, I guess I've still got a fun toy to play with. Kem, do you think Summit Racing would be able to plug in the numbers for me?? I know my brother has gotten some pretty decent technical help from them before.

 

ask over in the 302 forum , there are guys with desktop dyno.

if you lower the gears it will help offroad so going to 4.10's would help or 4.56 if you plan on running a 35".

its possible to that your tranny cant handle the new power and the torq converter is slipping. that year e4od wasnt the best.