1UZ with single exhuast after cats what size

[madmont]

When I did my conversion i did not have room for the cats at the end of the manifold so I moved them back using 2 1/2 in pipes and then into a 3 in system with straight through mufflers.This arrangement produced pathetic low end power but good top end. I then replaced the 2 1/2 in pipes with 2 in pipes which improved matters somewhat. I was unable to fit a y piece which gave equal lengths to the pipes from the manifolds so i fitted a balance pipe
and my own custom built terminator box built from 100mm dia tube in a y configuration after the cats.This has given me satisfactory low end torque although the exhaust does not sound like a V8 anymore. It is much quieter with this arrangement. See pics

 

[deankdx]

madmont that is one complicated exhaust you have there!

i still dont understand the idea of the balance pipe? my Dads got a Leyland P76 alloy V8 in a 1970 ford transit and unless he made a balance pipe like yours it would not fit(he wouldnt like that to be the lowest part of the car) its a 4.4 litre motor but only revs to say 5000rpm, he's running twin 2" pipes and a sports muffler(not straight through) without balance pipe and it goes very well, and has a sporty note(has a good firing order for note anyway) that is what i'd do to the 1UZ if i could run a duel system

 

[madmont]

The balance pipe serves a similar function to an x pipe or y pipe
it smoothes out the pulses from the exhaust manifolds and gives better flow
as a result

 

[hi-lex]

isnt a balance pipe only meant for twin pipes all the way through? kinda defeats the purpose of a balance pipe to then join it to one? or am I just lookn at it wrong?

 

[madmont]

Before i fitted the balance pipe my pipes were unbalanced due to the unequal lengths of the pipes feeding into the single pipe and the exhaust pulses were probably working against each other.

 

[Peewee]

Here is my current setup (the LHS extractor is slightly different than you see in this pic)

http://www.oz-enet.com.au/~peewee/extractors/

http://www.oz-enet.com.au/~peewee/muffler/

 

[deankdx]

peewee thats a very neat exhaust sytem, must have cost a packet for the time involved.

i'm starting to think i might build a BIG garage first as i think i'll run out of room pretty quick once i start with a half cut in a million pieces?

 

[Peewee]

peewee thats a very neat exhaust sytem, must have cost a packet for the time involved.

You're not wrong there...

 

[Cabear]

nice setup! i want to do something like this for my gs400!

 

[deankdx]

well funnily enough the decision has been made bye someone else, instead of doing this conversion i'm buying the same setup(almost i was going to use manual) and the guy that did this conversion has used(may change a few things yet) front engine pipes and manifolds that came with crown half cut to the point just under driver(australian RHD) then uses a CAT and main muffler (no resonator) from a 5litreV8 VN comodore. then out the tail pipe (assuming same diameter as muffler and cat)not sure if it would be 2.25 or 2.5" but at idle it sounds Quiet and has a note similar to a Rover 3500 V8 found especially in a SDI, range rover seem to sound gruntier? sounds quiet even when raced, doubt it would be louder than a new falcon or commodore6

see this thread for more info on the car http://lextreme.com/forums/showthread.php?goto=newpost&t=2167

 

[deankdx]

picked up car yesteday, blew diff up already.

the car is using 2.5" cat, muffler and tailpipe.(sounding more like an 8 now after blowing out cobwebs).

CAT is close to ground and may not pass 100mm clearance to ground, if i have to modify i may change a few things,
car has room for two main mufflers and can run twin exhaust 1 each side at rear. if theres enough clearance room, should i run two new engine pipes 2" into a Y peice(JBrady design) then into 2.5" CAT and then into another Y into twin 2" glass pack sports mufflers(what other cheapish nice note options) then out twin 2" tail pipes. would this suit a STANDARD 1UZ from crown with auto and 3.45LSD, standard manifolds and a standard airbox from a V8 commodere(may cut front out a little for cold air intake)

any further suggestions would be good, i will post a pic of current setup when i get it up on ramps soon.

 

[deankdx]

pics of current setup in falcon

 

[madmont]

Your system looks pretty ordinary
The stock system that the motor had originally works quite well
I would try to keep the lengths of the pipes from manifold to y piece the same like this one under new holden x8

 

[madmont]

this is what they put behind Ls1 v8
Some people replace them for better performance note the double balance pipes

 

[deankdx]

thats very neat madmont, i was thinking in tight ass mode and trying to keep existing cat, but on second thoughts, i would prodably like this theory, out of manifolds into cat each side, then into Xpipe like the bottom pic, then into 2 soprts mufflers and out twin out the back all in 2" i think this should work well, wonder if Jbrady is reading this? i would like to have a bit of a note in the exhaust, its sounds pretty good now.

 

[thefastj]

maybe them dual balance pipes are the reason the ford v8's sound so much better?? lol

j/k. but ALL ford V8's SOUND better than chev ones... no questions asked.
performance is another thing tho.

 

[Peewee]

The LS1 is just a fairly **** sounding motor.

 

[madmont]

Monaro ls1 only has 1 balance pipe

 

[madmont]

the system with 2 balance pipes ran into this muffler
the systems with 1 balance pipe merged after the resonators into 2 1/4 single