87/88 Throttle body comparison (pics)

[Jim2]

From the outside, they're the same. Inside, the 87 has a thinner wall..

from the back... 58 mm - 50 mm

 

[Jim2]

 

[InsaneRedRooster]

What is the relevance?

Sent from my PC36100 using Tapatalk

 

[alwaysFlOoReD]

Relevance is more airflow IF you can use it.

Richard

 

[Jim2]

What is the relevance?

I posted those pics because I had a hard time finding a straight comparison when I was looking for one.. it's a simple mod, bolts right up.

http://www.therangerstation.com/tech_library/Kunz_Korner.htm

"Next on induction if the throttle body, this is a relatively simple choice, the ones on the 86-87 2.9's are much larger and basically your only bolt on piece and tend to increase power in the 3k and up range, without one of these I would find it very difficult to make much power normally aspirated, so I would include this on the must have list."

 

[dave2575]

I posted those pics because I had a hard time finding a straight comparison when I was looking for one.. it's a simple mod, bolts right up.

Agreed, I was looking for some pics before I did my swap and couldn't find a good comparison photo. Thank you for sharing.

 

[Jim2]

Agreed, I was looking for some pics before I did my swap and couldn't find a good comparison photo. Thank you for sharing.

cheers, glad to help.

The previous owner of mine did some other mods before I got it, so I wasn't sure if he had already swapped it or not.
I even got a chance to look at an 87 from the outside, and it looked the same as mine.. I was wondering at that point..

Now I know, don't even need to measure anything.. if it has the thinner wall, it's an 86-87.. simple as that.

 

[AllanD]

THEORETICALLY greater airflow.

In point of fact the larger TB actually flows more air than the engine can actually take in which is why 2.9's have little distinction in throttle position above 3/4throttle.

This however can be used to advantage.

Not to get more air into the engine, but to use the larger TB with the 1988-up TP sensor on an 88-up 2.9 engine...

Runnig the SAME ammount of air into a 1988-92 2.9 while the computer THINKS the engine is getting
whatever ammount of air the smaller TB would deliver at 3/4-7/8, this keeps the management system
in "closed loop" and running relatively more lean.

To understand the point of this you need to know that the 2.9's by design and setup run TOO rich under most circumstances (look at the layer of BLACK SOOT inside your tailpipe)
and they can run much more lean...

This is how you get more power AND 25+ mpg from a 2.9.

The real secret is to NEVER give the computer a Full throttle signal from the TPS.

With the BIG TB on a later computer/engine this is EASY.

AD

 

[Jim2]

...use the larger TB with the 1988-up TP sensor on an 88-up 2.9 engine...

Runnig the SAME ammount of air into a 1988-92 2.9 while the computer THINKS the engine is getting
whatever ammount of air the smaller TB would deliver at 3/4-7/8, this keeps the management system
in "closed loop" and running relatively more lean.


...The real secret is to NEVER give the computer a Full throttle signal from the TPS.

AD

That's genius! I'll have to give it a try.
The 87 TB came with the TPS, so I didn't change it yet.

One question.. because I really don't care about MPG..
My Ranger is for track only. The the throttle is usually WOT, or all the way closed.. like a light switch. It's very rare that the throttle gets feathered.
If I swap back to the '87 TPS, will it still give enough fuel at WOT?