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4.0 HO performance?

19XJ90

NAXJA Forum User
Location
Magna, Utah
I have read through most the performance pages on here.

What I am looking to do is change to a bigger Throttle body on my 92 laredo, is there a stock jeep TB that is larger that will go right on my intake?

I know with the 5.2 motors there are alot of TB options, and in the past, I have found alot of manufacturers to use the same style TB on a few models and make one that is bigger.

SO, the stock 4.0 TB is TINY, can I use a 4.7, or newer 4.0 TB?
 
From what i know guys have been able to use 65mm tb from a mustang (dino did this). Apart from that fastman sells 65 mm tb foe a jeep 4.0.

Unless you have a stroker or some other high performance mods you will not gain anything more then you would from a 62mm one which requires no modification od the intake manifold.
 
sorry, i take that back, just noticed you have the renix system. You can probably use a 62 mm bored TB if you can modify your TPS
 
19XJ90 said:
I have read through most the performance pages on here.

What I am looking to do is change to a bigger Throttle body on my 92 laredo, is there a stock jeep TB that is larger that will go right on my intake?

I know with the 5.2 motors there are alot of TB options, and in the past, I have found alot of manufacturers to use the same style TB on a few models and make one that is bigger.

SO, the stock 4.0 TB is TINY, can I use a 4.7, or newer 4.0 TB?

Small confusion - your moniker indicates RENIX, while you're asking about HO. They are different - what year rig are you working with?

Later rigs seem to be able to accept Ford throttle bodies easily, and there are aftermarket TBs aplenty for that if you don't want to get yours bored out (keep it as a spare, replace it for Air Police inspections, ...)

Earlier (1987-1990) RENIX 4.0 uses a different throttle body, and pretty much the only option you have for an easy job is to get yours bored, or get one from a junkyard or a parts rig and bore that (which I know I'd prefer - what if I screw up?)

Ah - just reread. Since you said "1992," you're definitely HO with a four-bolt throttle body. Yes, you should be able to just get a bored SBFord (5.0L/302ci) throttle body and drop it on. The main thing you'll note is a quicker throttle - if you want more engine performance, you're going to want to do more work. But, if you want a crisper throttle, you're going to see that with a bored throttle body.

(rav - I can see why you missed it. I did, until I thought I should reread it. I'm glad I did...)
 
19XJ90 said:
I have read through most the performance pages on here.

What I am looking to do is change to a bigger Throttle body on my 92 laredo, is there a stock jeep TB that is larger that will go right on my intake?

I know with the 5.2 motors there are alot of TB options, and in the past, I have found alot of manufacturers to use the same style TB on a few models and make one that is bigger.

SO, the stock 4.0 TB is TINY, can I use a 4.7, or newer 4.0 TB?

There's a variety of 60mm and 62mm bored TB's that you can choose from. This page on my performance website gives you all the necessary info:

http://www.jeep4.0performance.4mg.com/intake.html

A 62mm TB is more than enough on a 4.0 and even on a mild 4.6 stroker. I'm the only one so far to have modified a Mustang 5.0 Cobra 65mm TB to fit on my 4.6 stroker and I can tell you it's overkill. The throttle response is very sharp and may be too sensitive for some. You can also modify a 4.7 V8 TB to fit but that's even bigger (68mm) and it's way beyond what you need.
 
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