Fixmyvw.com

Author Topic: restrictive exhaust Qs  (Read 5255 times)

Reply #15January 24, 2010, 04:53:58 pm

8v-of-fury

  • Guest
Re: restrictive exhaust Qs
« Reply #15 on: January 24, 2010, 04:53:58 pm »
Back pressure is nessary on gassers but not Diesels. The better the Diesel breaths, the better she runs.
But does that apply to non turbo's ?

Yes sir! the fact that diesels do not need back pressure and gassers do, is soley based on the fact that gas engines have valve overlap because of cam design. because of the tight tolerances of these diesels there is no overlap.. therefore no need for back pressure.

Obviously it would be impossible to have 0 back pressure on a normal car unless you are running just the manifold.. but the less there is on a diesel the better. A turbo diesel will have just as much backpressure straight piped.. as an N/a would have with a single normal muffler on it.

either way it is probably 12% of what was there stock :) rip that old exhaust off.. 2.5" and a Turbo muffler outback! will be very UN restrictive. :)

Reply #16January 24, 2010, 05:05:21 pm

macka

  • Veteran

  • Offline
  • ***

  • 957
Re: restrictive exhaust Qs
« Reply #16 on: January 24, 2010, 05:05:21 pm »
I have 3 inch SS at home waiting to be made up. Its gonna be much better.
Quote from: Vincent Walden
I do know that I drive torque,  while listening to my friends prattle on about horsepower.

Reply #17January 24, 2010, 05:12:19 pm

rabbitman

  • Veteran

  • Offline
  • ***

  • 2787
Re: restrictive exhaust Qs
« Reply #17 on: January 24, 2010, 05:12:19 pm »
Back pressure isn't the deal, it's velocity that you want so the outgoing gasses sorta suck the incoming air into the cylinder right before the ex valve closes. No good unless you have some valve overlap.
'82 Rabbit, I put on a euro vnt-15, 2.25" DP, 2.5" exhaust, the result.....it whistled.

I removed the turbo, made a toilet bowl 2.5" DP, the result....it was deafening. Now it has a homemade muffler up front and a thrush in the rear, the result.....less loud.
Watch: AGENDA, GRINDING AMERICA DOWN

Reply #18January 24, 2010, 06:55:45 pm

8v-of-fury

  • Guest
Re: restrictive exhaust Qs
« Reply #18 on: January 24, 2010, 06:55:45 pm »
rabbitman you just described Back-Pressure with different words. lol ;)

I concur :)

Reply #19January 25, 2010, 10:24:43 am

Rabbit on Roids

  • Guest
Re: restrictive exhaust Qs
« Reply #19 on: January 25, 2010, 10:24:43 am »
diesels dont need pack pressure. its just making the exhaust leave the engine a little harder. we already have 24:1 compression, we dont need back pressure too...

Reply #20January 25, 2010, 11:27:27 am

1oldcj

  • Guest
Re: restrictive exhaust Qs
« Reply #20 on: January 25, 2010, 11:27:27 am »
What's the best exhaust I can put on my 92 1.6l n/a ?

I have an all stock system and want her to breath better!

Reply #21January 25, 2010, 11:38:22 am

veector

  • Junior

  • Offline
  • **

  • 95
Re: restrictive exhaust Qs
« Reply #21 on: January 25, 2010, 11:38:22 am »
I remember reading somewhere that 8v gasser manifolds fit but not sure about the advantage
1981 Jetta D
1997 Jetta TD

Reply #22January 25, 2010, 12:03:10 pm

Rabbit on Roids

  • Guest
Re: restrictive exhaust Qs
« Reply #22 on: January 25, 2010, 12:03:10 pm »
3" straight pipe is the best exhaust to run on your 1.6 td. no muffler, no restrictions.

as for the gasser intake manifold, it fits, but it takes a bit more than bolting it on to get it to fit.you have to have a low mounted turbo, so it sits closer to the block and axle. otherwise the gasser manifold hits the turbo.

Reply #23January 25, 2010, 12:03:45 pm

GEE-BEE

  • Veteran

  • Offline
  • ***

  • 1604
  • Personal Text
    1981 with South African front end ,42 k original
Re: restrictive exhaust Qs
« Reply #23 on: January 25, 2010, 12:03:45 pm »
2.25 OR 2.5 Diameter

 I would go S/S up there..

techtonicstuning.com

Gee-Bee
1.9 AAZ, CHD 5spd with Peloquin
KO4/KO3 Hybrid turbo
Giles Pump OHC
Complete Techtonics 2'5 S/S DP and Exhaust
Coilovers, MKII Pedal Swap,G60 BRAKES
MK1 JETTA DASH
675MM 16V radiator (MKII) PASSAT DUAL FAN
42K original miles , South African Front End
15x6 Le Casletts 195-45-15

Reply #24January 25, 2010, 12:09:24 pm

Rabbit on Roids

  • Guest
Re: restrictive exhaust Qs
« Reply #24 on: January 25, 2010, 12:09:24 pm »
2.25 OR 2.5 Diameter

 I would go S/S up there..

techtonicstuning.com

Gee-Bee

techtonics is expensive...
a local exhaust shop could do just as good of a job, for probably half the price.

and hes gonna make a 3" down pipe, so why go 2.5 after the 3" DP? thats just stupid...
and the fact that he was asking for the best performing exhaust for a diesel vw. techtonics exhaust systems work alright, but they dont make a 3" system, and i dont they sell an exhaust system without a muffler. and he probably doesnt wanna spend his left nut on an exhaust system. he has a turbo, thats enough muffler.

Reply #25January 25, 2010, 01:44:48 pm

GEE-BEE

  • Veteran

  • Offline
  • ***

  • 1604
  • Personal Text
    1981 with South African front end ,42 k original
Re: restrictive exhaust Qs
« Reply #25 on: January 25, 2010, 01:44:48 pm »
They will build it with or without a muffler

I paid 315.00 for s/s 2.5 DP

300.00 for 2.5 Complete exhaust

Is that expensive ?

Mine's perfect,like everything else I do....

You get what you pay for ....

I do agree 3' would be nice but I think I would have a little clearance issue on my caddy

1.9 AAZ, CHD 5spd with Peloquin
KO4/KO3 Hybrid turbo
Giles Pump OHC
Complete Techtonics 2'5 S/S DP and Exhaust
Coilovers, MKII Pedal Swap,G60 BRAKES
MK1 JETTA DASH
675MM 16V radiator (MKII) PASSAT DUAL FAN
42K original miles , South African Front End
15x6 Le Casletts 195-45-15

Reply #26January 25, 2010, 02:12:00 pm

Rabbit on Roids

  • Guest
Re: restrictive exhaust Qs
« Reply #26 on: January 25, 2010, 02:12:00 pm »
615 bucks is expensive for a single pipe exhaust, yes. i personally would never spend that much for exhaust on ANY vw, not even a BRAND NEW one...

my buddy had a custom full dual exhaust put on his V8 s-10 for under 250 bucks. and that was with the cost of the flowmasters and everything. and the guy that did it, did a damn good job doing it. it wasnt stainless tho, but most people dont care if its stainless or not.

and that sounds a little snobby/egotistical saying that EVERYTHING you do is perfect..
there is no such thing as perfect, so go figure. there are only people who think "perfect" exists.


Reply #27January 26, 2010, 10:00:08 am

veector

  • Junior

  • Offline
  • **

  • 95
Re: restrictive exhaust Qs
« Reply #27 on: January 26, 2010, 10:00:08 am »
the TT option is indeed a pricy one as the exhaust guy quoted me less than half of that for about the same thing.  Im just saving up a bit of cash and the car will be dropped of for some work sooon
1981 Jetta D
1997 Jetta TD

Reply #28January 26, 2010, 10:01:12 am

dieselsmoke

  • Guest
Re: restrictive exhaust Qs
« Reply #28 on: January 26, 2010, 10:01:12 am »
Veector

I am running the same setup as you are but I am running at 15 psi of boost. Do you have an intercooler on yours or an egt gauge when running at 18-20 psi?

Reply #29January 26, 2010, 10:40:25 am

GEE-BEE

  • Veteran

  • Offline
  • ***

  • 1604
  • Personal Text
    1981 with South African front end ,42 k original
Re: restrictive exhaust Qs
« Reply #29 on: January 26, 2010, 10:40:25 am »
So you wouldn't buy A full Ti exhaust if you had the money ?


I don't have time to make my own, I would rather pay a professional to get what I want, I was very happy with techtonics.

I sent them three different turbos and manifolds so they would have the pattern for others


I think some exhaust systems are a work of art.



Some exhaust systems for the Turbo 997 Porsche are over 6K without headers or Tip's
I mfg a strap seal for different exhaust mfg's for the muffler straps.

GB
« Last Edit: January 26, 2010, 11:01:07 am by GEE-BEE »
1.9 AAZ, CHD 5spd with Peloquin
KO4/KO3 Hybrid turbo
Giles Pump OHC
Complete Techtonics 2'5 S/S DP and Exhaust
Coilovers, MKII Pedal Swap,G60 BRAKES
MK1 JETTA DASH
675MM 16V radiator (MKII) PASSAT DUAL FAN
42K original miles , South African Front End
15x6 Le Casletts 195-45-15

 

S-PAutomotive.com