Canada Catalys

Author Topic: ahu vs 1.9idi  (Read 8458 times)

May 23, 2012, 11:55:20 am

1life2live

  • Junior

  • Offline
  • **

  • 92
ahu vs 1.9idi
« on: May 23, 2012, 11:55:20 am »
I currently have a 1984 jetta with a 1.6td with the fuel turned up and the boost set to 20psi. I was planning to swap in a tdi out of a 97 jetta that i bought as a complete running car. I have just been offered a 1.9 idi with only 40k on the clock with the reciepts showing when it was installed. Im now looking for advice on the best direction to go whether i take the time to swap in the tdi or go the easy route and bolt in the 1.9. Is there a big power difference between the two? What are the pros and cons between the two engines and is it worth the extra time and hassle to do the tdi swap. I had plans of bigger injectors and a chip on the tdi but i could spend that money on modding the pump on the 1.9. Any help would be great



Reply #1May 23, 2012, 01:25:17 pm

libbydiesel

  • Veteran

  • Offline
  • ***

  • 2982
Re: ahu vs 1.9idi
« Reply #1 on: May 23, 2012, 01:25:17 pm »
The AAZ and AHU/1Z will make similar power provided they are both intercooled, similar turbo efficiency, etc.  The TDI does not like to rev as high, is about 10-15% more fuel efficient and cannot drop pre-chambers. 
Use, abuse or ignorance of any information is at your own risk, confirmation or refutation is your own responsibility, no further 'proof' will be given, take it or leave it, YMMV,terms subject to change without notice, avoid contact with eyes or skin, contents known to cause cancer in California

Reply #2May 23, 2012, 03:05:17 pm

CRSMP5

  • Guest
Re: ahu vs 1.9idi
« Reply #2 on: May 23, 2012, 03:05:17 pm »
crazyandy did some math for me... my tdi-m is pullin aprox 6200rpm... at that point no more pull.. stock 98 02a, 3rd gear 78mph via gps.. 21psi of boost on the stock pea shooter tdi turbo too....

imo biggest differance.. no pre cup to drop.. no glow plugs required unless sub 20*f too.. but i have yet to drive a aaz to see how it feels vs my tdi-m..

Reply #3May 23, 2012, 05:02:07 pm

1life2live

  • Junior

  • Offline
  • **

  • 92
Re: ahu vs 1.9idi
« Reply #3 on: May 23, 2012, 05:02:07 pm »
What exactly is the pre chambers? I plan on inter-cooling either motor and would like to do some mods to either of them. I know it will be easier to do the aaz since I won't be dealing with the computer and I also won't have to worry about the egr. Something about being able to tune the ecu on the ahu is tempting to do the extra work.

Reply #4May 23, 2012, 05:19:10 pm

CRSMP5

  • Guest
Re: ahu vs 1.9idi
« Reply #4 on: May 23, 2012, 05:19:10 pm »
prechamber is the swirl chamber the injector/glow plug go into on a idi head.. for somereason some fall out as you drive and kill what was a good engine..

Reply #5May 23, 2012, 09:30:45 pm

1life2live

  • Junior

  • Offline
  • **

  • 92
Re: ahu vs 1.9idi
« Reply #5 on: May 23, 2012, 09:30:45 pm »
Ok that's what I thought u were talking about. My friend had that very thing happen to him after a machine shop resurfaced his head and removed them. They didn't stay in after they re installed them and trashed the motor.

Reply #6May 24, 2012, 09:58:28 am

nathan_b

  • Veteran

  • Offline
  • ***

  • 361
Re: ahu vs 1.9idi
« Reply #6 on: May 24, 2012, 09:58:28 am »
crazyandy did some math for me... my tdi-m is pullin aprox 6200rpm... at that point no more pull.. stock 98 02a, 3rd gear 78mph via gps.. 21psi of boost on the stock pea shooter tdi turbo too....

imo biggest differance.. no pre cup to drop.. no glow plugs required unless sub 20*f too.. but i have yet to drive a aaz to see how it feels vs my tdi-m..


I've driven a couple aaz mk3s and they are DOGS compared to the ahu.

No way ahu/aaz make similar power in my book.
Plus, ahu is less smokey, and easier to find parts for.
Egts are wayy cooler too.
81 caddy frankentd 02a, 99.9 tdi jetta, 00 golf

Reply #7May 24, 2012, 10:36:18 am

libbydiesel

  • Veteran

  • Offline
  • ***

  • 2982
Re: ahu vs 1.9idi
« Reply #7 on: May 24, 2012, 10:36:18 am »
When stating that they will produce similar power, I wasn't talking about stock form.  In stock form the AAZ was one of the most de-tuned piles of steaming dog poop that VW ever produced, rivaled only by the 1.6ECOdiesel.
Use, abuse or ignorance of any information is at your own risk, confirmation or refutation is your own responsibility, no further 'proof' will be given, take it or leave it, YMMV,terms subject to change without notice, avoid contact with eyes or skin, contents known to cause cancer in California

Reply #8May 26, 2012, 09:23:59 pm

8v-of-fury

  • Guest
Re: ahu vs 1.9idi
« Reply #8 on: May 26, 2012, 09:23:59 pm »
1.9 AAZ 105-7tq stock compared to the 1.9 AHU 150tq stock. Stock the AHU would be way quicker, not to mention the always spooled k03 hitting max torque at 18-1900 rpm.

Reply #9June 02, 2012, 04:04:02 pm

CdnVWJunkie

  • Veteran

  • Offline
  • ***

  • 309
Re: ahu vs 1.9idi
« Reply #9 on: June 02, 2012, 04:04:02 pm »
1.9 AAZ 105-7tq stock compared to the 1.9 AHU 150tq stock. Stock the AHU would be way quicker, not to mention the always spooled k03 hitting max torque at 18-1900 rpm.

Pretty sure stock tq on the aaz is more like 120 not 105.

Reply #10June 03, 2012, 11:23:22 am

8v-of-fury

  • Guest
Re: ahu vs 1.9idi
« Reply #10 on: June 03, 2012, 11:23:22 am »
I looked it up, 1.6TD was rated at 69 HP @ 4500 RPM and 98 ft.lbs. @ 2500 RPM.  The 1.9TD (AAZ) was rated at 75 HP @ 4500 RPM and 114 ft.lbs. at 2500 RPM.

Right in between the both of our guesses.

Reply #11June 03, 2012, 11:24:07 am

8v-of-fury

  • Guest
Re: ahu vs 1.9idi
« Reply #11 on: June 03, 2012, 11:24:07 am »
Even if the AAZ and AHU made the same torque rating, the fact that the AHU makes it at 1800 as compared to 2500 is what you are going to feel while driving it.

Reply #12June 03, 2012, 11:34:05 am

libbydiesel

  • Veteran

  • Offline
  • ***

  • 2982
Re: ahu vs 1.9idi
« Reply #12 on: June 03, 2012, 11:34:05 am »
Add an intercooler (like the AHU has) and appropriate boost fuel enrichment (like the AHU has) and the AAZ will produce similar power/torque to the AHU.  It will produce it somewhat later in the RPMs, will be comfortable revving higher and will consume 10-15% more fuel in the process. 
Use, abuse or ignorance of any information is at your own risk, confirmation or refutation is your own responsibility, no further 'proof' will be given, take it or leave it, YMMV,terms subject to change without notice, avoid contact with eyes or skin, contents known to cause cancer in California

Reply #13June 03, 2012, 02:44:09 pm

Henk

  • Junior

  • Offline
  • **

  • 111
Re: ahu vs 1.9idi
« Reply #13 on: June 03, 2012, 02:44:09 pm »
or get an AHU and add a decent FMIC, more fuel, more boost and get even more power again, for probably very little drop in economy
Mid Engine
Berg Cup
M-TDi
Caddy!

Reply #14June 03, 2012, 03:19:30 pm

homerj1

  • Veteran

  • Offline
  • ***

  • 429
Re: ahu vs 1.9idi
« Reply #14 on: June 03, 2012, 03:19:30 pm »
BUT the 1.9idi is basically 1 wire to run engine.

VS  The sensor-laden electronic TDI

I've had both, love the simplicity of the iDI, but have found the ahu with 205 nozzles tdi to have more power - as I ignore the CHECK ENGINE light as accelerating...

Although I lean to the simplicity of the IDI

 

Fixmyvw.com