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Throttle1982
12-17-2006, 09:49 PM
Does anyone have a bored out throttle body on their 4.0L?

If anyone does, do they recommend doing it? Does it add a lot more h/p and do you sacrifice gas mileage?

How much would it cost to do so?

Anyone running a TB spacer? How thick?

B
12-17-2006, 10:27 PM
the 4 liters get better gains than most out of a spacer and bigger thottle body as the shape of the intake's 90's right below it ...one of the mags just did a test of all the differnt combos and the inline 6 gained more % wise than other set up's ie v6 v8

id do it the more efficent it is the better mileage u get ... [cheers]

Tunabomber
12-17-2006, 11:14 PM
ooooooooo i hope thats true somebody do it then let me know or help me do mine:rolleyes:

Mr Vic
12-17-2006, 11:39 PM
i have a throttlebody spacer on the 4 banger in my jeep. small noticable difference in the top end, does not affect milage, on a 4.0 should be better.
cost me about $60 to get throttle body spacer of ebay

DirtyComanche
12-17-2006, 11:58 PM
Since this thread is ugh.


TB spacers are a JOKE! They shift the power band to being slightly higher in the rpm range by increasing effective intake size (or runner length, if you want). Essentially, it'll give you 1-2HP more in the higher RPMs and take 1-2HP away in the lower RPMs.

All to the tune of $140! Sweet deal!


A bored TB is a good free(ish) mod though. If I was nice (or if somebody else is) they'd post up the DIY bored TB how-to. Buying one pre-bored is uh, silly.


If you want a little more power out of the 4.0:

Renix style 4.0 - put the HO head and intake on.
HO 4.0 - put the 2000+(?) intake on, it is more efficent.
HO 4.0 - Use a mustang TB (IIRC) as it is a couple MM bigger than you can bore your's.
All - port head's intake (all you need is a dremel and a spare head and a LOT of time)


Personally, I do none of these things. The 4.0 is a brick. If I convert mine to propane I will bore the TB and maybe look at some of the other options. As it is, picking up 2-5HP per mod really isn't worth the time. There's a lot more things wrong with my rig than the lack of power.

Throttle1982
12-18-2006, 10:55 PM
Has anyone tried this tho? other than Dirty Comanche that would say otherwise?

Anyone make a new intake for the 4.0L? I heard you could make it out of 3" exhaust elbow... ?

Nutbar
12-18-2006, 11:10 PM
The larger throttle body, performance chip, mild camshaft changes(not race type cam profiles as the ECM can't adapt to the changes), cold air intake, and throttle body spacer are all good mods on the 4.0 ( you can only do the cold air . . . or . . . the throttle body spacer on the XJs and I would suggest the cold air over the spacer personally)

and don't worry about Dirty he has never had a good 4.0 so he is a little biassed my 4.0 has lots of jam in a Comanche with 33s, 4.10 gears, automatic, with a cam, chip, cat and cat back exhaust, and a K&N filter in the stock box(cold air will come just haven't got around to it yet) My 4.0 pulls hard 1500 to 5700 rpm

DirtyComanche
12-18-2006, 11:15 PM
and don't worry about Dirty he has never had a good 4.0 so he is a little biassed my 4.0 has lots of jam in a Comanche with 33s, 4.10 gears, automatic, with a cam, chip, cat and cat back exhaust, and a K&N filter in the stock box(cold air will come just haven't got around to it yet) My 4.0 pulls hard 1500 to 5700 rpm



I didn't say the thing sucked. But it's not a real performance engine, and sure as hell never will be. You can put a lot of money into one and still only make a few gains in power. Sure, it's no where near as bad as the toyota or suzuki guys; but it's definatly not good value.


And I've driven a HO. I can't tell the difference. Maybe I was just numbed by the sheer power.


Oh, and I'll admit my 4.0 has a free-flowing exhaust and a CAI. Not to mention a fair amount of internal clearancing. But, these mods didn't cost me anything (other than the stupid exhaust pipe).

Nutbar
12-18-2006, 11:23 PM
Not a performance engine I know a few people and speed companies that would say different they are just not a commonly performanced piece I have seen a few AMC inline 6s that make some extreme power you just gotta know what parts to use and combine them right.

At my shop we are in the process of building a 4.6 stroker mtr nothing is real extreme on it and it should be in the range of 300 to 350 hp when we are done.

Throttle1982
12-19-2006, 06:05 AM
Thanks Nutbar, appreciate the info.

So whats the best option for a cold air intake then? Make my own or pay the highschool dropouts at lordco some ridiculous amount of money for a piece of pipe with a couple angles welded onto it?

DirtyComanche
12-19-2006, 07:26 AM
So whats the best option for a cold air intake then? Make my own or pay the highschool dropouts at lordco some ridiculous amount of money for a piece of pipe with a couple angles welded onto it?



Did you answer your own question?


Mine is an old intake I found in the junkyard.

Camorokee
12-19-2006, 09:32 AM
how about a hesco built 4.6 I put in a yj that was 300hp? Guess that isn't very high hp for some people.

DirtyComanche
12-19-2006, 04:40 PM
Well, spit in the general direction of a SBC and you'll be making 300HP.


So no, it's not.

Throttle1982
12-19-2006, 06:59 PM
anyone have any pictures of their home made intake?

J20
12-19-2006, 07:12 PM
Not a performance engine I know a few people and speed companies that would say different they are just not a commonly performanced piece I have seen a few AMC inline 6s that make some extreme power you just gotta know what parts to use and combine them right.

At my shop we are in the process of building a 4.6 stroker mtr nothing is real extreme on it and it should be in the range of 300 to 350 hp when we are done.


I agree with mickey ive seen some pretty sick stroked 4.0s in the last year.......

Mr Vic
12-20-2006, 11:03 AM
anyone have any pictures of their home made intake?

i got one from ebay for around $60 after tax and shipping. works good no complaints about it. pretty much the same as the one in the link below

http://cgi.ebay.ca/JEEP-WRANGLER-2-5L-4-0L-FULL-AIR-INTAKE-1991-1992-1995_W0QQitemZ160064711572QQihZ006QQcategoryZ38634 QQrdZ1QQcmdZViewItem