BroncoII4x4.com

i got a 1990 bronco 2 i picked up for $625 with 57,000 original on it and i figured it would be a nice project truck.
but i dont have alot of money and dont really know what to do to get a little more umph outta it got any sugestions??

You are going to be somewhat limited on what you can do to get more power from your 2.9 without spending $$. These engines were only put into RBV's for 6 years, but there are a lot of them in wrecking yards and back yards still. Beware of early 2.9 heads, they were very weak and quite often cracked.
The first thing would be an 86-87 throttle body from a wrecking yard or someone who might have one left from an engine swap, the 88-92 2.9 throttle bodies were about 54mm, the 86-87's were 58mm. that isn't going to give you a lot of power by itself, but it is a start. Figuring out a different air inlet with a gauze type air filter will give you another 1 or 2 HP in the upper RPM's. This link takes you to my PhotoBasket page: http://s960.photobucket.com/albums/ae89 ... intake.jpg. It isn't pretty, but it works very well, the picture is how it is set up to go onto my 4.0 in my 86 B2, so the hose is different. People have made various comments about this, mostly negative, but, it works good and costs little. It does have some draw backs, if you are interested, ask.
Ranger Dave's site has a ton of information about things to do to RBV's, his link is:
http://rangerdave.freeforums.org/index. ... 29b55fe263
This link is to another site that deals almost exclusively with the earlier RBV's, (Ranger Based Vehicle) Rangers, Bronco II, Explorer, there Tech Library is pretty extensive and will give you some idea of what you can do, if you can find the parts, money and ambition.
http://www.therangerstation.com/tech_library/index.php
This is another site that also has some very good information.
http://www.broncoii-ranger.com/forum/vi ... 1f0b33991e
You should also check out this site a little more in depth.
There were 2 versions of the 2.9, not really different versions, they are the same engine, but, as you will find out in investigating them, you either had a real screamer or a boat anchor. I have seen both in the same model year, no real reason why, just the way they were.
I caught hell from a site moderator for doing what I just did here, I hope this doesn't happen here, I am only attempting to give new RBV owners some readily available information, not drive them to other sites or say that we don't have or know what they are asking. Pimping another site is not my goal, education is what this is about.

Ray

alright thank you ray and this 1 is de4ffinately a screamer.. i will have to try that but will changing from the 54 to the 58mm help that much to be able to notice the difference?

My 86 B2 came with the 58mm and it was a screamer, even before changing the exhaust and the intake, however, I owned a 92 Ranger that had a boat anchor 2.9, when I installed a 58mm on it there was a noticeable difference, I did not upgrade the intake system at that time.
If you are serious about squeezing a little more out of your 2.9, I would do the throttle body first, then upgrade the exhaust to whatever the pipe size is between the cats, then do the intake system.
When you do the exhaust, you may notice a little loss on the lower end performance, but you will gain that and more at or near highway speed. You should also notice an increase in MPG at highway speed if you can keep your foot out of it.
The intake system is going to be where you will see the largest gain, but only after you do the exhaust, it mostly appears when you are moving and forcing air into the intake, there is very little benefit at the low end. If you do the intake system before the exhaust, the stock exhaust robs you of some of the performance gain you should realize.
This is one of those things of making small changes to get small returns from each, that will turn into a larger gain in the end.

Ray

That's great Dave, love your videos.

Ray

alright that simplifies alot of it for me. the last question is do you know why they changed the throttle body if it gave it more power?
there wasnt anything bad about them was there?

That question has been asked a lot. I know it didn't give any extra power to have the smaller throttle body. I don't ever remember hearing a justifiable reason for the change.
Some thing that is common knowledge with those who have been around these engines for a while. The 86-87 model years had a .020" shorter deck height than any of the other 2.9's, the shorter deck height supposedly gave it a boost in compression. That could be the reason for the smaller throttle body bore on the 88 and later.
I am interested in whether the throttle body change helped yours or not?
To make a long story short, I hope, a fellow I know had a 89 B2, 2.9, 4x4, 3.73, that he had built the engine up on. He however didn't change the throttle body, had never heard that there was any difference from year to year. The truck had been run on a chassis dyno and put out just over 195 peak HP. We changed the throttle body about a year later and he ran it for 6 months or so, but said that he couldn't feel or see any difference. He did some work on the truck that took a couple weeks to complete, during that time he picked up another ECM for an 87 and put it in when it went back together. Shortly after that he got it back on the dyno, 213 peak HP. He stated more than once after that, that he had not made any changes to the engine while he had it down, that the only change made that could have made any HP was the replacing of the ECM and the 58mm throttle body.
I AM NOT ADVOCATING TO DO THIS, THIS IS AN ISOLATED CASE THAT WENT IN THE RIGHT DIRECTION, MOST DON'T.

Ray

youll only notice a difference at the higher RPM's. disconnect the battery overnight after you swap to the bigger TB

RClem wrote: back on the dyno, 213 peak HP

Yes, I don't know what all was done, but he had a small fortune tied up in it, to say the least, it would get out out of it's own way.
I don't think he had many problems with the truck and that much power, except for the damn A4LD, that was his weak point. He had a couple of transmission shops go threw and supposedly beef them up, but they were only lasting him about 20 thousand before he had to do it again.
I did see his dyno readouts, he was real proud of those.

Ray

FDLBLDF

OK
Spell it out, I:m not into acronyms.

Ray

Ray,

This is nothing against you. I find 213 hp out of a basically stock 2.9 is a little hard to swallow!

I don't disagree that you saw a print out that said 213 peak hp. My comment was simply that "Figures Don't Lie But Liars Do Figure". That was a personal quote from one of my math teachers. he was warning us that you could make any figure work in an equation if you change the variables.

that would be impressive to get 213 out of a 2.9 but im just looking to give it a little gitty up n go for when i wanna go have fun but still get the better gas milage bcuz its still gonna be a family car and a everyday car just a toy on weekends