Mustang 4.6 throttle body on a 4.0 SOHC Explorer

[Flann18]

I was wrong about the size of the throttle body. The new one I put on was 80 mm. I had to enlarge the hole on the plenum chamber so it would work. I don't know too much about the codes and stuff, so I can't really tell you much about it. All I was told is that it is running too lean.

 

[spindlecone]

I was wrong about the size of the throttle body. The new one I put on was 80 mm. I had to enlarge the hole on the plenum chamber so it would work. I don't know too much about the codes and stuff, so I can't really tell you much about it. All I was told is that it is running too lean.

How did you enlarge the intake> which is 65 mm, what makes you think you are running lean, are you haveing detonation problems? have you had an A/F ratio done?

 

[Flann18]

A mechanic i know ran an OBD 2 Scanner on it and then told me it was lean. It also didn't run nearly as well as it used to. I didn't have an A/F ratio done. It was a REALLY quick off the line, which was fun, but its top speed was only about 70 mph. I just put the old TB back on and it seems to be fine. The check engine light went off and it feels much better.

 

[RickOTR]

I've had the Ford Racing TB and a 75mm MAF on my X since 2001 and have had no problems. Anything larger then 70mm TB or 75mm MAF is overkill without larger fuel injectors and a computer chip to increase the fuel flow. I also run an adjustable FPR on my X to increase fuel pressure to 35 psi at idle due to the fact I have 24lb fuel injectors.
Remember, when you increase air entering an engine you have to increase the fuel flow to avoid a lean engine check light.

 

[CDW6212R]

The factory sized MAF, fuel injectors, fuel pressure, and throttle body are close to perfect for the stock RPM range. Changing any of those by a large amount will not create a positive affect.

The 24 l/hr injectors are completely unnecessary for anything but a major air flow increase. Changing to any throttle body or MAF, or air cleaner(not intake), will not create a major air flow increase.

This is not a Mustang forum, even though there are a lot of novices here who may be influenced by similar "bigger is better" erroneous thinking. Go read a few thousand magazines since the early 90's of the 302HO engine's existance. The ideal sizes of the above mentioned parts have already been tested and retested hundreds of times.

Please do not suggest that you have learned something that no one else has in these past 20 years about the SFI Ford 302 needs. Stay with virtually stock air inlet parts on the 96-01 Explorer 302, unless you are actually changing major parts, such as heads, camshaft, and intake manifold. The MAF sensor and throttle body have the least affect on air flow of an engine so well developed. Those two can be made slightly larger without much harm.

The stock throttle body is virtually perfect for the stock parameters. Some have suggested a slight gain, fine they spent a couple hundred dollars and gained a couple of horsepower, great.

The MAF in stock size does a great job, and a larger size will do equally well, but still again only a couple of HP might be gained. That still is not worth the effort or money spent.

For those looking for real improvements, look elsewhere. Hundreds of people have discovered where money is best spent. Work on the exhaust, all of it. Change as many of the various fluids to synthetic fluids, check out Al's mileage thread. Keep very high quality filters, plug wires etc. in it.

For real HP gains, the only viable solution is to start saving money, and plot on changing heads, camshaft, and even compression if you can afford it. For the cost of a complete stroker short or long block, if you need a new engine anyway, there's a big HP improvement. Good luck

 

[aldive]

The factory sized MAF, fuel injectors, fuel pressure, and throttle body are close to perfect for the stock RPM range. Changing any of those by a large amount will not create a positive affect.

The 24 l/hr injectors are completely unnecessary for anything but a major air flow increase. Changing to any throttle body or MAF, or air cleaner(not intake), will not create a major air flow increase.

This is not a Mustang forum, even though there are a lot of novices here who may be influenced by similar "bigger is better" erroneous thinking. Go read a few thousand magazines since the early 90's of the 302HO engine's existance. The ideal sizes of the above mentioned parts have already been tested and retested hundreds of times.

Please do not suggest that you have learned something that no one else has in these past 20 years about the SFI Ford 302 needs. Stay with virtually stock air inlet parts on the 96-01 Explorer 302, unless you are actually changing major parts, such as heads, camshaft, and intake manifold. The MAF sensor and throttle body have the least affect on air flow of an engine so well developed. Those two can be made slightly larger without much harm.

The stock throttle body is virtually perfect for the stock parameters. Some have suggested a slight gain, fine they spent a couple hundred dollars and gained a couple of horsepower, great.

The MAF in stock size does a great job, and a larger size will do equally well, but still again only a couple of HP might be gained. That still is not worth the effort or money spent.

For those looking for real improvements, look elsewhere. Hundreds of people have discovered where money is best spent. Work on the exhaust, all of it. Change as many of the various fluids to synthetic fluids, check out Al's mileage thread. Keep very high quality filters, plug wires etc. in it.

For real HP gains, the only viable solution is to start saving money, and plot on changing heads, camshaft, and even compression if you can afford it. For the cost of a complete stroker short or long block, if you need a new engine anyway, there's a big HP improvement. Good luck

The gentleman was talking about his 4.o SOHC, not a 302.

 

[CDW6212R]

The general idea still applies Al. Ford did not poorly develop these engines with missmatched fuel injectors, fuel pressure, etc. You have been tinkering with your drivetrain more than myself, he, or others. You know very well that the stock balance of components is very very good, for the stock RPM range.

The engines built in the last 15 years don't suffer from lack of development by the manufacturers. In the early years of fuel injection, a great deal could be gained by searching for better parts balance. Those were also less powerful operating systems. These engines since the early 90's are far more refined, and the OS(PCM) can compensate for many more changes. But the stock parts are just about ideal for the stock RPM range.

My intention is simply to alert other unknowing members that more harm, less improvements, and money wasted, can result from changing any or all of those components. Any changes to them need to accompany great care, and knowledge of what is to be gained, and lost. Regards,

 

[aldive]

I beg to differ. Have YOU tested the TB and a larger MAF yourself?

I have had good gains in HP as well as gas mileage when using this TB

Further a larger MAF ( housing; C & L ) with stock Ford electronics has nedtted me good gains.

 

[CDW6212R]

Yes, a few HP Al. Read the post again which I responded to. He mentioned having larger injectors, plus more fuel pressure. Those are massive changes compared to the TB and MAF sensor.

My post was clear, some small gains can be had sometimes, with a careful change of TB or MAF. Changing the other items, the major items, are not helpful, or desirable. The PCM can compensate for them far better than in the past. If the injectors and pressure are changed on a 1980 model engine, the A/F ratio is changed dramatically, more than those PCM's can handle.

These PCM's today are wonderful compared to the first, EECIII and EECIV versions. The components need to be in a useable operational and air flow range. The stock parts are, and other than the TB and MAF, nothing else is needed, or helpful.

Thank you Al for your detailed testing of various parts, and your labor and effort to help everyone. You have learned some things from others, and tried to not waste time on some things. We need to do the same for known items, to help people to avoid wasting time and money on them.

That's my point, no one should waste money, time, or labor changing some things for a stock application. The fuel injectors and fuel pressure fall square in that category. They are items many have learned about the waste, before. We should try to keep others from making the same mistakes. No offense RickOTR, just rtying to help.

 

[RickOTR]

Installing aftermarket spark plug wires and changing to synthetics did nothing for me. When I installed the bigger TB and MAF the engine became lean to the point it was setting the CEL light everythime I got on the throttle. The new computer chip really helped open up the fuel curve. The regulator and fuel injectors where just experiments, and nothing more but at least I have some controll over the amount of fuel entering the engine. 19lb FI are ok up to 325 HP... above that you need to be looking into larger injectors. There are no companies that sell aftermarket manifolds, heads, ect. for the SOHC. However, there is a company in Germany that can grid you a camshaft but they want $800 for the pair. The SOHC has a lot of potential and Ford knows that but decided to keep HP levels reasonable for fuel economy, emissions low, and the price of an Explorer within reason.

 

[CDW6212R]

Good, glad to hear. The PCM's are the most powerful part of the system these days. The costs for the programmers or chips, etc. are modest, but worth it for mileage and power.

From your signature, the 70mm TB is the only item that looks out of balance.The PCM can correct for fuel injectors and pressure easily. What is the stock 4.0 TB size, 65mm or 60mm?

I'd like to try a 65mm that is port matched to the intake, and retune. The 65mm size was discovered to be the best in Mustangs ten years ago, for stock RPM vehicles(under 6000RPM). Good luck,

 

[RickOTR]

I don't believe the 70mm TB, FPR, are a waste of money. I gained 11 dyno proven hp from them. I can adjust fuel pressure from 30 to 45 psi just by turning a small screw. In order to have the computer change fuel pressure I would have to have the chip reburnt. That would be a hassel. The stock TB by the way is 68mm.

 

[celly]

I can adjust fuel pressure from 30 to 45 psi just by turning a small screw.

You can adjust fuel pressure through the TB? Not that I'd know better, but that's new to me. I had that TB for a while on my SOHC Sport before I sold it. "Monmix" has it now. I didn't notice that much of a difference in performance, but then again some of the changes we make to our rides are so subtle anyhow.

 

[RickOTR]

Not by the TB... through the fuel pressure regulator. I bought an aftermarket FPR and replumbed the fuel hoses.

 

[celly]

Not by the TB... through the fuel pressure regulator. I bought an aftermarket FPR and replumbed the fuel hoses.

DUH. Sorry. Misunderstood completely. Must be Monday.

 

[Green98XLT]

I believe *ALL* late model stock vehicles can be improved upon in terms of increased power and torque BUT at the expense of economy and emissions. The factories are never concerned with power production, they are purely looking for economy (especially in the case of a 4WD SUV) and low emissions and both cause poor performance.

This is why just a flasher or good chip can show such significant gains on late model vehicles! Take a look at what they are getting out of a new Duramax or power stroke diesel!! But you are correct with the common misconception that many have.... Bigger is NOT better. If you upgrade your MAF and TB and exhaust it must be done with consideration and it must match other components of the engine.

An engine is still an engine and they all still operate on the same principle- get more air AND fuel in and it will run better.

 

[4.0L Sleeper]

Does anyone know of a direct bolt up TB for the 2001 Sport 4.0L, I know BBK and Ford Racing make them but I dont believe for this year. If anyone could help, that'd be awesome, thanks so much!!!

2001 4.0L Sport
K&N Cold Air Intake
True Dual Flowmaster Super 40's
Superchip's x-Cal2 Programmer
Eaton Limited Slip

 

[aldive]

OHV or SOHC?

 

[spindlecone]

Did they make the OHV engine in 01?

 

[4.0L Sleeper]

its the SOHC, I need to give it more air because I am about to get the heads done and a cam as well, thank you very much for your input