I have 99 ford f-150 4.2 V6 and i was looking into a Throttle body spacer. I wanted more power and better gas milage. Does anyone have one that has worked good for them? Thanks

 

4.2flybyu:

First and foremost, Welcome To FTE!

This is a general opinion of TB Spacers...

On a different site I am on I actually looked at a dyno sheet of a user who dyno'd with and without the spacer. When the spacer was on he lost 5 rwhp. IMO, they aren't worth the money. Most of the people I have talked to consider them a waste of money...better off a doorstop than an engine piece.

Secondly, the spacer claims to add more power by swirling the air into the engine. I haven't actually seen that happen on paper yet. Also, you have to think of it like this - the shortest distance between 2 objects is a straight line. In other words the faster and quicker the air gets into the engine, the more power you are going to get. The spacer actually adds more distance for the air to travel to get to the engine. This is my opinion based on what I've seen. You are better off getting an Intake for about $30 more...which WILL get you more power for sure. I hope this helps.

 

I think the whole TB Spacer falls into the same category as exhaust and intakes. By itself, it will lose power, but in conjuction with other modifications, like intakes and exhaust, it can help.

Im no expert, but with my intake exhaust, etc. and TB Spacer, I have way more power, AND still got 19 MPG on my 1800 mile trip last week. I dont have any proof that it helps or hurts, so this is all IMHO.

I think Toms postings of how true duals can actually lose you RWHP without a counterbalance on the other side of the flywheel pertain to this item. Same thing with headers...they lose HP if you just stick them on with no other mods. Just a thought.

Garrett

 

I've seen before/after dyno's of cars who have added TB spacers as well as intake spacers. Some will gain a couple HP to the wheels and some will lose a couple HP to the wheels. But I'm only talking about 2-3hp. Dyno's are not perfect...you could run the same car on one multiple times without changing anything and still get 2-3hp difference. So from what I've seen a TB spacer by itself won't add anything.
Dual exhaust by itself does for a fact give you more HP...as will an intake. An engine is an air pump, the faster you can move air through it the more power it will make. Your thinking is right though, a better flowing exhaust without something on the intake side to flow better will result in a loss of backpressure. Backpressure=Torque. You'll gain the horsepower up on the top end, but you'll lose a little torque down low, but with a near stock engine we're only talking single digit gains/losses here.

 

No, a duel setup on our trucks by itself hurts the motor, no back pressure. It will help out a V-8, but not a 6. we need SOME back pressure, which the duals by itself we cannot get any.

 

Yea, I think the TB Spacer is going to pretty much be a mixed review. With the right conditions and component system you could see a few small gains with it. If you are just buying the spacer, don't waste your money. There's no way you could tell the difference from just that. Like Garrett said, get a intake, exhaust and the spacer and you'll probably notice a bit more of a difference.

 

I just remember hearsay. Tom was told by his local shop that he would dyno less RWHP with true duals. Like I said, hearsay, but it makes sense to me..no backperssure could cause a styock engine to lose dynoed RWHP. Dunno, IMHO.

Garrett

 

I’m with V6Mustang on the true duals. Back pressure is NEVER desirable. For high-performance purposes, backpressure in an exhaust system increases engine pumping-losses and decreases available engine power. Maximum mid-to-high RPM power will be always be achieved with the lowest possible backpressure
IMO the whole “engines require backpressure" thing is a myth.

An engine needs the highest flow velocity possible (intake and exhaust) at any given RPM for quick throttle response and torque. The problem stems from the fact that the flows are dramatically different across the RPM range. A small diameter exhaust pipe might give you maximum unimpeded gas velocity at 2000 RPM. This would give you great off-idle acceleration, but after 2000 RPM the exhaust gas volume begins to exceed the amount that can flow unimpeded through the pipe and you have BACK PRESSURE. To overcome the limitations of the undersized exhaust pipe your engine needs to literally pump the exhaust out the end of the pipe. This seriously inhibits peak performance for any number of reasons.

If we install a larger diameter exhaust pipe, we now have enough pipe volume to flow the unimpeded gas velocity at mid-to-high RPM without BACK PRESSURE. However, at lower RPM’s the gas volume is not large enough to maintain the flow velocity in the larger pipe and low-end throttle response suffers.

Exhaust systems are a compromise, you can maximize for low-range and mid-range performance or mid-range and high-end performance but you cannot simultaneously maximize for all three because of the differences in flow volume and velocity.

 

Run a motor without back pressure. and please do not complain when you burn your valves

 

I have not read or heard anything to indicate that risk and the trucks at 105,000 and runs like a top. Why do you think less back pressure would cause a burnt valve?

 

The hot exhaust does not exit properly, burns your exaust and intake valves back in the motor, do not remember the whole specifics of it though.....or maybe it was that it leaves to rapidly or somesuch, do not remember exactly right now....gotta locate a friend to get the whole scoop again....and yes I have seen it happen and know what it was due to, being as we had just changed the exhaust with what was thought would be a better flowing on,e well apparantly it flowed to much.

 

Well that's an entirely different discussion and thread alltogether. Back to the TB Spacers. 4.2flybyeu, do you have a final verdict?

 

I agree with what you say, but it is completely irrelevant to the original statement.

You are talking hi-performance, as you mentioned in your second sentance, is not what we are talking about. We are strictly talking about putting a true dual setup on a BONE STOCK 4.2L. So, yes, in hi-performance cases, you are correct. But, IMHO, I disagree that having little to no backpressure with nothing forcing, or letting in, more air is a good thing.

v/r,
Garrett

 

Hey thanks guys i think ill just go with an intake becuase i havent heard much possitive results on the TB spacer.
thanks

 

No problem! Here's a link for a couple to get you started!

www.motorhaven.com