exhaust for a t3

[alexgingles]

I'm wanting to make a larger exhaust for a jetta.  It's a '91 Eco but somewhere in the past, someone swapped in a hydro MF with a stock t3.  Since I've owned it, I have resealed the pump and did the governor mod and a few other tweaks to the pump.  It runs good and has decent power but I know the stock Eco exhaust with the cat and everything is holding this motor back. 

Is adding a larger free flowing exhaust system really going to make my t3 spool up any quicker and pull harder?  I don't have a tach or boost gauge currently to compare to.

This car is a DD and I don't race it so to speak.. I may push it to its shift points on the speedo once a day to feel that nice pull at the end of the power band.

Will I get more bang for my buck swapping to a k14 and larger exhaust?  I only want to fab the downpipe once.

I know this is a hard question since it boils down to personal preference.  Thanks for any help!

[Wayland]

The stock exhaust is too small for a stock engine, so yes, I'd say you'll notice quite a difference.

[stewardc]

You will notice a HUGE difference with a good 2.5" downpipe and exhaust. You should also add a manual boost controller and up the boost a few pounds. An intercooler is also a nice mod. Turn in the fuel screw about 1/4 turn.
As for the K14, I've tried both and like the T3 better. I think it makes more boost easier on the top end.

[rodpaslow]

My T3 starts spooling with a 2.5" exhaust at about 2400 rpm.  I rarely spin over 3500 -3700 rpm.  I bought a vnt and planning to put it in sometime.  My $.02 I think a vnt is the way to go.

The T3 will easily hit 25 psi though if your looking for high end performance.  I have my wastegate held closed in order to do this.
Fabricating a downpipe isn't very difficult in a MK2, mine was in a MK3, a bit tighter between the body and rack & pinion.

[R.O.R-2.0]

My T3 starts spooling with a 2.5" exhaust at about 2400 rpm.  I rarely spin over 3500 -3700 rpm.  I bought a vnt and planning to put it in sometime.  My $.02 I think a vnt is the way to go.

The T3 will easily hit 25 psi though if your looking for high end performance.  I have my wastegate held closed in order to do this.
Fabricating a downpipe isn't very difficult in a MK2, mine was in a MK3, a bit tighter between the body and rack & pinion.

VNT is definitely the way to go. downpipe fabrication is CAKE!
and they spool super low, and still make 25 psi on the top end..  my $.02...

saw my boost gauge hit 25 psi yesterday, first time in a VERY very long time..

you can get way more than 25 psi if your vaines dont open completely.. i blew a block to bits one time with a VNT, accidently had the vaines set to the closed position, instead of open.

the second i hit the throttle, the boost gauge ROCKETED to the peg below 30 psi, then the engine went BOOM.. didnt even have to pop the hood to know what i had done..

coolant and oil all down the front drivers side. all over the fender, wheel, running down the head light and grille..

and that was just on the outside of the car, think of what it looked like under the hood!

[Alcaid]

Broken rod(s) and/or cracked piston(s)?

[RadoTD]

Broken rod(s) and/or cracked piston(s)?

What he said ^^
What typically fails first? and was that engine still stock?

[R.O.R-2.0]

Broken rod(s) and/or cracked piston(s)?

the block breaks.. not the internals..

you just cant keep the head bolted down afterwards..

[theman53]

IIRC ROR2.0 was using a completely stock 1.5....I think a 1.6TD with some mods should hold up better

[R.O.R-2.0]

yea.. i had a stock 1.5D

stock head bolts, stock head gasket.

[Alcaid]

1.6TD with girdle, even better