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Engine Specific Info and Questions => IDI Engine => Topic started by: burn_your_money on March 07, 2009, 03:32:13 pm

Title: Where's your redline?
Post by: burn_your_money on March 07, 2009, 03:32:13 pm
Just wondering how high you guys rev your motors.

I've taken my 1.6 NA up to 6000 a couple of times but normally shift around 4000.

So, how high have you taken your motor and it still survived?
Title: Where's your redline?
Post by: UnderPSI on March 07, 2009, 04:01:18 pm
I take my 1.5 na way over 4000 when I'm wheelin. Hasn't died yet.
Title: Where's your redline?
Post by: maxfax on March 07, 2009, 04:58:11 pm
I generally shift between 4000 and 4500 but have pushed it to 6000 more than a few times..  Tyring to pass going up the mountain with an NA no less...
Title: Where's your redline?
Post by: Rich_91 on March 07, 2009, 05:27:18 pm
I dont have the gov mod (yet  :oops:  ), so I dont get past 3800-4000 without bogging down. My usuial shift point is 2250 - 2500

And 6000!!!#!  WOW!  Anything over about 3500 scares me a bit... I have visions of parts coming out of the hood at that rpm!

Not to hyjack, but do these motors make power up that high? (5-6k?)
Title: Where's your redline?
Post by: maxfax on March 07, 2009, 05:36:10 pm
Pends on the build..   I know my engine is pretty much done a little under 5000..  All I have is a governor mod, and larger exhaust..  With a Giles super pump I'm guessing it is better...
Title: Where's your redline?
Post by: jtanguay on March 07, 2009, 06:11:57 pm
Quote from: "Rich_91"
I dont have the gov mod (yet  :oops:  ), so I dont get past 3800-4000 without bogging down. My usuial shift point is 2250 - 2500

And 6000!!!#!  WOW!  Anything over about 3500 scares me a bit... I have visions of parts coming out of the hood at that rpm!

Not to hyjack, but do these motors make power up that high? (5-6k?)


if you modify the governor properly they can rev up to and maybe higher than 6k and deliver all the fuel you need.  timing advance mod might be necessary at that point though... because you need enough timing advance to properly burn that extra fuel  :wink:
Title: Where's your redline?
Post by: the caveman on March 07, 2009, 06:23:48 pm
Last year with all the snow and my unlimited slip transmission the 1.7 na got wound up to at least 5500 a few times. Not great since the motor wasn't really warm but ya gonna do? certainly didn't seem to affect it. It really astonished me when i first found this site. I was under the assumption that a diesel just couldn't breathe well enough do wind up like  they manage to.
Title: Where's your redline?
Post by: Vincent Waldon on March 07, 2009, 06:48:01 pm
Routinely wind up past 4000, generally consider 5000 to be "enough". :wink:
Title: Where's your redline?
Post by: UnderPSI on March 07, 2009, 09:48:25 pm
I run 4000 at 60mph. I was concerned about cruising rpm that high, but it runs good.
Title: Where's your redline?
Post by: AudiVWguy on March 07, 2009, 09:49:24 pm
Did you guys ever read in the Bently about setting the max rpm? If I recall, they talk about revving the motor to 5500 rpm and adjusting it to there.
I don't have my book right now, somebody else will have to look.
Title: Where's your redline?
Post by: allsierra123 on March 07, 2009, 11:25:03 pm
I was kind of curious what RPM people are cruising at not so much the revs. I dont think the revs are that bad on it. But I wonder how high is to high for prolonged driving.
Title: Where's your redline?
Post by: Rabbit on Roids on March 08, 2009, 01:10:05 am
i read in a bently that you adjust a TD motor to 5850 rpms for the max setting. so if thats a stock absolute redline.. then why cant we balance our bottom ends and turn 6500 or more? i really dont know how many revs im turning, but i shift my gears when the motor starts getting quiet if im really trying to get somewhere fast. i dont really have a top speed limiter screw setting on my pump either. its just backed way way out. this probably isnt the best way to get revs out of your diesel motor, but whatever, i did it when i was still way new to diesels. and it still works too good. so im not gonna fix it.
Title: Where's your redline?
Post by: DCC on March 08, 2009, 03:49:07 am
I usually change around 4k, but when needed, I've seen 5k sometimes... the engine didn't complain... yet. :lol:

About cruising.. I had to do 900 km (550 miles) some time ago to pick up a GTI interior (mint condition, pickup only :o), and keeping a good pace, the engine did go between 3500-4000 all the time (this worked as an italian tune-up, btw).
Title: Where's your redline?
Post by: theman53 on March 08, 2009, 12:11:22 pm
The first n/a I owned I got it stuck in the driveway. After trying to be nice getting nowhere and then upset, I held the skinny pedal to the floor for about 4-5 minutes popping the clutch from 1st to reverse. I got it out and that is why I didn't hold it there longer, I wouldn't recommend this practice and I didn't have a tach so I have no clue what the rpms were. I did continue to drive it for another year then sold it with no engine related troubles.
Title: Where's your redline?
Post by: burn_your_money on March 08, 2009, 12:24:26 pm
I don't really like the feeling of cruising at high RPMs for extended periods of time. 3000 is the highest that I like my motor turning at on the highway. Lately I do find myself cruising at 3600 though.
Title: Where's your redline?
Post by: RabbitJockey on March 08, 2009, 12:24:45 pm
Quote from: "Rabbit on Roids"
i read in a bently that you adjust a TD motor to 5850 rpms for the max setting. so if thats a stock absolute redline.. then why cant we balance our bottom ends and turn 6500 or more? i really dont know how many revs im turning, but i shift my gears when the motor starts getting quiet if im really trying to get somewhere fast. i dont really have a top speed limiter screw setting on my pump either. its just backed way way out. this probably isnt the best way to get revs out of your diesel motor, but whatever, i did it when i was still way new to diesels. and it still works too good. so im not gonna fix it.



5850 is a dry rev i doubt anyone could go that high on the road with out the governor mod
Title: Where's your redline?
Post by: Rabbit on Roids on March 08, 2009, 01:47:40 pm
since these motors are so similar to the 8v gasser motors, why is everybody so afraid of revs? i want to turn as many revs as i can possibly squeeze out of that little motor. i understand not wanting high rpms for freeway cruising, but c'mon. it would be nice to have 6500 on tap whenever you needed it. maybe im just dreaming tho..
Title: Where's your redline?
Post by: Vincent Waldon on March 08, 2009, 02:03:08 pm
I don't think it is a matter of fear, more a matter of "what's the point". ;-)

Mechanically the gassers and diesels are based on some similar factory castings, but the engines are very very different in many many ways.  

Specifically for this thread, maximum torque and power and delivered at a significantly lower RPM on these diesels as opposed to their gasser cousins. As a relative example of two similar MK3 VW engines in the 2l range:

AAZ diesel:     max 75 hp @ 4000 RPM, max 111 ft-lbs @ 2000 RPM
ABA gasser:  max 114 hp @ 5400 RPM, max 112 ft-lbs @ 5400 RPM

Torque's peaked at 2000 RPM, hp at 4000... no point in reving these babies into the stratosphere.
Title: Where's your redline?
Post by: Rabbit on Roids on March 08, 2009, 02:29:27 pm
so basically they arent even building anymore power reving them any higher than about 4000?
Title: Where's your redline?
Post by: DVST8R on March 08, 2009, 02:36:06 pm
Well as has been seen in the past, add a bigger turbo and some head work, and you can see that TQ peak move to the right a quite a bit. There have been motor's here that have made power right up to 6000rpm. Probably would have gone past that, but ran out of fuel.
Title: Where's your redline?
Post by: allsierra123 on March 08, 2009, 03:19:58 pm
well my gearing will be low I will probably be seeing 3500 at 60 mph. I wish it were lower. But the auto box just isnt going to do much better I fear. So I just wonder if it will do it any damage or if its just going to be a matter of wasting fuel.
Title: Where's your redline?
Post by: subsonic on March 08, 2009, 03:36:57 pm
Quote from: "Vincent Waldon"
I don't think it is a matter of fear, more a matter of "what's the point". ;-)

Mechanically the gassers and diesels are based on some similar factory castings, but the engines are very very different in many many ways.  

Specifically for this thread, maximum torque and power and delivered at a significantly lower RPM on these diesels as opposed to their gasser cousins. As a relative example of two similar MK3 VW engines in the 2l range:

AAZ diesel:     max 75 hp @ 4000 RPM, max 111 ft-lbs @ 2000 RPM
ABA gasser:  max 114 hp @ 5400 RPM, max 112 ft-lbs @ 5400 RPM

Torque's peaked at 2000 RPM, hp at 4000... no point in reving these babies into the stratosphere.


Vince,
Those numbers are stock I assume.   I see the difference you are pointing out and agree to a point.  To interject a little chaos theory into the debate, (this is always the fun part :P ) we need to be able to break our apples and oranges into different sub species.  
1.  Stock 1.6 N/A
2.  Stock 1.6TD
3.  Stock 1.9TD
4.  Modded 1.6 N/A (various fuel pump mods, exhaust mods, cold air  
     intake etc.)  
5.  Modded 1.6TD  ( Huge range of mods.  Need to group similar.
     Example 1.6/1.9 mod,  Super pump, etc)
6.  Modded 1.9TD  (same as above.)

I think that each group or sub-group will have greatly different RPM / TQ / HP ratio’s
Of course it would be cool if we could all dyno before and after mods for hard numbers, but that could get pretty darned expensive. So who wants to be the applied physics guru and help us approximate with different inputs.
 :lol:
Title: Where's your redline?
Post by: Vincent Waldon on March 08, 2009, 04:03:16 pm
Quote from: "subsonic"

Vince,
Those numbers are stock I assume.


Yuppers.

Good point in that they will vary as we add modifications... but (since you brought up chaos ;)) that will also be a challenge putting things into hard defined buckets... I'd suspect *every* engine out there will run a bit different on the dyno, particularly as we add our own interesting mods, in our own way, in our own particular order.

My (albeit small) point... my guess is that (except in cases of extreme modification!) all of the power is long gone by 6000 RPM, so to me there's no point stressing the engine up there. ;-)
Title: Where's your redline?
Post by: Aki-76 on March 08, 2009, 11:24:09 pm
My old engine (eaton/holset) take 6000rmp very easy (max power is 5500-5700,200kw,in wheel) and new twin turbo,i hope it take 7000 rpm.More rpm=more power  :twisted:
Title: Where's your redline?
Post by: gldgti on March 09, 2009, 12:34:54 am
i ahd the fuel screw on my old 1.5 n/a wound a long way in, and it would rev and rev and rev.... i used to cruise pretty fast too, and it didnt mind.

my aaz with all its mods seems happy enough to shift around 43-4500 rpm... and i've taken it to about 5200 on the odd occasion... but given the aaz crank is 4.5kg heavier than the 1.6 one, i dont think it'd like a lot more. my general shift point for normal driving is about 3000rpm.
Title: Where's your redline?
Post by: arb on March 09, 2009, 07:07:57 am
Quote from: "Rich_91"
I dont have the gov mod (yet  :oops:  ), so I dont get past 3800-4000 without bogging down. My usuial shift point is 2250 - 2500

And 6000!!!#!  WOW!  Anything over about 3500 scares me a bit... I have visions of parts coming out of the hood at that rpm!

Not to hyjack, but do these motors make power up that high? (5-6k?)


Yeah, I'm old school. Anything past 4000 scares me too.
Title: Where's your redline?
Post by: subsonic on March 09, 2009, 07:43:52 am
On my the 2.0 16v cr, max torque is between 1500 and 2500rpm.  When I drive it hard, I shift around 4300-4500.  After that it is still pulling, but the amount is small.  It has tapered off and starting to flatline.
Title: Where's your redline?
Post by: molgrips on March 09, 2009, 08:16:53 am
Quote
so basically they arent even building anymore power reving them any higher than about 4000?


They do generate more power as you rev higher BUT the issue is that in terms of acceleration you might be better off shifting up and taking advantage of the extra torque at lower revs in a higher gear.  As I had to explain to my Dad as he was driving our rented house-moving van and attempting to pass another car...  He (a non-diesel driver) was quite surprised how much extra acceleration there was upon UP shifting.