Re: more power from 4.0
 

These trucks came from the factory with a VERY restrictive exhaust.
Mostly the muffler and tailpipe. Some of them even had a 1.875 inch
tailpipe, which choked the engine at anything above 3,000rpm. I
installed a replacement muffler that used a 2.250 inch outlet and a
tailpipe from an older model which was also 2.250 inch. You would
not believe what it did for my 3,000 to 5,000rpm power.

The NAPA part number for the "Turbo Muffler" I used is 17748 and the
tailpipe is 44171. You may need a short piece of straight pipe to go
between the muffler and the convertor, and you will need new clamps to
attach the tailpipe.

A caution, anything less restrictive than a "turbo muffler" type will
give you an annoying exhaust sound like some kid driving his ricer
with a fart pipe.

Bruce

Re: more power from 4.0
 

These trucks came from the factory with a VERY restrictive exhaust.
Mostly the muffler and tailpipe. Some of them even had a 1.875 inch
tailpipe, which choked the engine at anything above 3,000rpm. I
installed a replacement muffler that used a 2.250 inch outlet and a
tailpipe from an older model which was also 2.250 inch. You would
not believe what it did for my 3,000 to 5,000rpm power.

The NAPA part number for the "Turbo Muffler" I used is 17748 and the
tailpipe is 44171. You may need a short piece of straight pipe to go
between the muffler and the convertor, and you will need new clamps to
attach the tailpipe.

A caution, anything less restrictive than a "turbo muffler" type will
give you an annoying exhaust sound like some kid driving his ricer
with a fart pipe.

Bruce

Re: more power from 4.0
 

These trucks came from the factory with a VERY restrictive exhaust.
Mostly the muffler and tailpipe. Some of them even had a 1.875 inch
tailpipe, which choked the engine at anything above 3,000rpm. I
installed a replacement muffler that used a 2.250 inch outlet and a
tailpipe from an older model which was also 2.250 inch. You would
not believe what it did for my 3,000 to 5,000rpm power.

The NAPA part number for the "Turbo Muffler" I used is 17748 and the
tailpipe is 44171. You may need a short piece of straight pipe to go
between the muffler and the convertor, and you will need new clamps to
attach the tailpipe.

A caution, anything less restrictive than a "turbo muffler" type will
give you an annoying exhaust sound like some kid driving his ricer
with a fart pipe.

Bruce

Re: more power from 4.0
 

On Tue, 13 Mar 2007 06:36:24 -0500, "DougW"
<post.replies@invalid.address> wrote:

>abomb69 wrote:
>> Is there a cheep way to get more power out of a 93 Cherokee 4.0? I've
>> been told about TB spacers but is there any other things besides
>> expensive turbo?
>
>spacers are junk, they just move the throttle body and essentially
>shorten the throttle cable. You can get the same general effect by
>gluing a block of wood to your right shoe.
>
>Cat-back, headers, a bored-out throttlebody, electric fan rather than
>motor driven, that's about it before you realy have to start opening
>the ol wallet. Then it's multispark ignition, porting, stroking, and
>or blower/supercharger. As they say at Hesco, "Speed costs money, how
>fast do you want to go?" :)

DougW:
Side question: Did you have to do anything special to your 4.0L after
supercharging it?

A friend installed a supercharger and is having issues with
knock/ping, but only in 3rd gear under full throttle(?).
(Sorry, don't know the brand at the moment.)

TIA

....

Re: more power from 4.0
 

On Tue, 13 Mar 2007 06:36:24 -0500, "DougW"
<post.replies@invalid.address> wrote:

>abomb69 wrote:
>> Is there a cheep way to get more power out of a 93 Cherokee 4.0? I've
>> been told about TB spacers but is there any other things besides
>> expensive turbo?
>
>spacers are junk, they just move the throttle body and essentially
>shorten the throttle cable. You can get the same general effect by
>gluing a block of wood to your right shoe.
>
>Cat-back, headers, a bored-out throttlebody, electric fan rather than
>motor driven, that's about it before you realy have to start opening
>the ol wallet. Then it's multispark ignition, porting, stroking, and
>or blower/supercharger. As they say at Hesco, "Speed costs money, how
>fast do you want to go?" :)

DougW:
Side question: Did you have to do anything special to your 4.0L after
supercharging it?

A friend installed a supercharger and is having issues with
knock/ping, but only in 3rd gear under full throttle(?).
(Sorry, don't know the brand at the moment.)

TIA

....

Re: more power from 4.0
 

On Tue, 13 Mar 2007 06:36:24 -0500, "DougW"
<post.replies@invalid.address> wrote:

>abomb69 wrote:
>> Is there a cheep way to get more power out of a 93 Cherokee 4.0? I've
>> been told about TB spacers but is there any other things besides
>> expensive turbo?
>
>spacers are junk, they just move the throttle body and essentially
>shorten the throttle cable. You can get the same general effect by
>gluing a block of wood to your right shoe.
>
>Cat-back, headers, a bored-out throttlebody, electric fan rather than
>motor driven, that's about it before you realy have to start opening
>the ol wallet. Then it's multispark ignition, porting, stroking, and
>or blower/supercharger. As they say at Hesco, "Speed costs money, how
>fast do you want to go?" :)

DougW:
Side question: Did you have to do anything special to your 4.0L after
supercharging it?

A friend installed a supercharger and is having issues with
knock/ping, but only in 3rd gear under full throttle(?).
(Sorry, don't know the brand at the moment.)

TIA

....

Re: more power from 4.0
 

Your talking about the muffler being sensitive someone put a little muffler
on this thing (like on on a car) it has the 2.25 outlet and inlets but the
stock one is like huge compared to the one on the truck now.


"Highcountry" <highcountry2000@hotmail.com> wrote in message
news:1173791584.562616.325020@j27g2000cwj.googlegr oups.com...
>
> These trucks came from the factory with a VERY restrictive exhaust.
> Mostly the muffler and tailpipe. Some of them even had a 1.875 inch
> tailpipe, which choked the engine at anything above 3,000rpm. I
> installed a replacement muffler that used a 2.250 inch outlet and a
> tailpipe from an older model which was also 2.250 inch. You would
> not believe what it did for my 3,000 to 5,000rpm power.
>
> The NAPA part number for the "Turbo Muffler" I used is 17748 and the
> tailpipe is 44171. You may need a short piece of straight pipe to go
> between the muffler and the convertor, and you will need new clamps to
> attach the tailpipe.
>
> A caution, anything less restrictive than a "turbo muffler" type will
> give you an annoying exhaust sound like some kid driving his ricer
> with a fart pipe.
>
> Bruce
>

Re: more power from 4.0
 

Your talking about the muffler being sensitive someone put a little muffler
on this thing (like on on a car) it has the 2.25 outlet and inlets but the
stock one is like huge compared to the one on the truck now.


"Highcountry" <highcountry2000@hotmail.com> wrote in message
news:1173791584.562616.325020@j27g2000cwj.googlegr oups.com...
>
> These trucks came from the factory with a VERY restrictive exhaust.
> Mostly the muffler and tailpipe. Some of them even had a 1.875 inch
> tailpipe, which choked the engine at anything above 3,000rpm. I
> installed a replacement muffler that used a 2.250 inch outlet and a
> tailpipe from an older model which was also 2.250 inch. You would
> not believe what it did for my 3,000 to 5,000rpm power.
>
> The NAPA part number for the "Turbo Muffler" I used is 17748 and the
> tailpipe is 44171. You may need a short piece of straight pipe to go
> between the muffler and the convertor, and you will need new clamps to
> attach the tailpipe.
>
> A caution, anything less restrictive than a "turbo muffler" type will
> give you an annoying exhaust sound like some kid driving his ricer
> with a fart pipe.
>
> Bruce
>

Re: more power from 4.0
 

Your talking about the muffler being sensitive someone put a little muffler
on this thing (like on on a car) it has the 2.25 outlet and inlets but the
stock one is like huge compared to the one on the truck now.


"Highcountry" <highcountry2000@hotmail.com> wrote in message
news:1173791584.562616.325020@j27g2000cwj.googlegr oups.com...
>
> These trucks came from the factory with a VERY restrictive exhaust.
> Mostly the muffler and tailpipe. Some of them even had a 1.875 inch
> tailpipe, which choked the engine at anything above 3,000rpm. I
> installed a replacement muffler that used a 2.250 inch outlet and a
> tailpipe from an older model which was also 2.250 inch. You would
> not believe what it did for my 3,000 to 5,000rpm power.
>
> The NAPA part number for the "Turbo Muffler" I used is 17748 and the
> tailpipe is 44171. You may need a short piece of straight pipe to go
> between the muffler and the convertor, and you will need new clamps to
> attach the tailpipe.
>
> A caution, anything less restrictive than a "turbo muffler" type will
> give you an annoying exhaust sound like some kid driving his ricer
> with a fart pipe.
>
> Bruce
>

Re: more power from 4.0
 

noneofyourbusiness wrote:

> DougW:
> Side question: Did you have to do anything special to your 4.0L after
> supercharging it?

I installed a boost-a-pump that increases the fuel pressure to 70 psi
and a pressure regulator on the fuel rail that's stonger than stock.

> A friend installed a supercharger and is having issues with
> knock/ping, but only in 3rd gear under full throttle(?).
> (Sorry, don't know the brand at the moment.)

If it wasn't there before then suspect dirty fuel filter or
clogged injectors. Also poor spark will cause problems.
If all else is fine have him try one range cooler on the plugs.
And don't use platinum or splitfire as they cary too much heat
and can cause detination problems.

If it was always there then he needs to retard the timing a bit
and increase fuel flow with either larger injectors or a higher
pressure pump/regulator. Some systems use a seperate injector.

--
DougW