Best turbo for low-end torque, K04? Highest hp on K04-20?

[nytoy]

Ok,

I've searched and read the FAQ's, I understand there are a few options for my car (99 'Avant 1.8TQM)

I've seen a kit from a while ago called the K04-20 which produced 300lb-ft of tq.

My question is, what are the largest numbers you can get from a K04?

Is there any small to medium sized turbo that can be fully spooled around 2000rpms like the K04 and make good torque?

Is there a difference in K04's? I.E. I hear some asking if it's a borg-warner, does that make a difference?

If I missed some ultimate K04 thread please direct me as I searched and wasn't able to find a thread to end all others. Thanks!

[VTAudiA4]

Ok,

I've searched and read the FAQ's, I understand there are a few options for my car (99 'Avant 1.8TQM)

I've seen a kit from a while ago called the K04-20 (ko4-015)which produced 300lb-ft of tq.

My question is, what are the largest numbers you can get from a K04?
300HP has been done before running meth with all the mods but you are looking somewhere around 250CHP with mods

Is there any small to medium sized turbo that can be fully spooled around 2000rpms like the K04 and make good torque?

Is there a difference in K04's? I.E. I hear some asking if it's a borg-warner, does that make a difference?
Borg Warner is the company that makes them so anything else usually means its a fake copy/cheap knock off.

If I missed some ultimate K04 thread please direct me as I searched and wasn't able to find a thread to end all others. Thanks!

Hope this helps. If you have any more K04 questions just PM me.

[offroader1006]

k04 is definitely the best low end turbo.

but as far as turbos go, thats an insult.

ideally if you have a turbo, you want power to increase with RPM, not nosedive after 5k like the itty bitty KKK's do.

[djwimbo]

The reason people ask if it's a Borg Warner or not is to avoid the eBay scam turbos.

A K04 will produce a huge torque spike but won't produce high HP #'s like a BT would. 300ft lbs or torque out of a k04 isn't that hard.
As far as any other turbo that'll spool at 2000rpms, sorry not going to happen. You want big numbers, you need a turbo that'll be efficient in higher RPM's. A GT25 or GT28 series turbo wouldn't be bad either.

If you don't mind me asking, what's the need for a huge torque spike in low RPM's? it's a killer on rods.

[nytoy]

The reason I want low end torque is I find it to be usable more than high end power, I've had both kinds of cars and you find yourself at 2000rpms about 50% more than 5000rpms during normal driving. I would be different if I'm out street racing or tracking the car, but I have a Z06 Corvette for that, so this is the daily driver / winter car. What would be the best components to piece together for a reliable and highest hp package on the K04. Is there still a K04-20 kit being offered somewhere?

[VTAudiA4]

ko4-020 are for V-Dubs and do not fit on Audi A4's. You need a ko4-015. Now to have a great setup you need an exhaust (anywheres between 2.25-2.75), fmic (ebay works but I would recommend racetec), injectors and software (GIAC is great), mbc or ebc...etc.....
and a bunch more but I already sent you a pm.

[mike-2ptzero]

The reason I want low end torque is I find it to be usable more than high end power, I've had both kinds of cars and you find yourself at 2000rpms about 50% more than 5000rpms during normal driving. I would be different if I'm out street racing or tracking the car, but I have a Z06 Corvette for that, so this is the daily driver / winter car. What would be the best components to piece together for a reliable and highest hp package on the K04. Is there still a K04-20 kit being offered somewhere?

You drive the power band not the other way around. If you increase the power and shift the power band to the right you end up changing the way you drive. The problem with the K03/K04 quick tq spike is that it is very short lived, so you get a very short burst and thats about it.


K04-20 is off of a transverse Audi 225TT, it is not going to work on your car. My guess is that you have been reading too many VW forums. There is a hybrid K04-23 or RS4 K04-25, but it isn't worth doing and there is no tuning for it.

K04-23 is most likely what your thinking about.



If you want a K04 setup go for the -15 version and a PC16 GIAC file which is for the ndbw cars. The highest K04 setup for the B5 is the J31 file which has been known to make over 320tq at the crank and around 250chp.


BTW a K04 still isn't going to be fully spooled till around 2700 rpms, so there is going to be very little power made at 2000 rpm.

[VTAudiA4]

Mike is here to drop some knowledge on all of us and EDUHMAHKATE us all. I always thought k04-20 where a V-DUB turbo. Learn something new everyday.

[mike-2ptzero]

Mike is here to drop some knowledge on all of us and EDUHMAHKATE us all. I always thought k04-20 where a V-DUB turbo. Learn something new everyday.

There is a nice thread on Vortex that gives all of that info.

[nytoy]

awesome thank you very much mike! and VTaudi

[andyrew]

NY toy... power is a shift away....

I know how you feel, I felt the same way with my chipped K03.. however going to an APR stage 3 (GT28R), there is not much drivability as far as power goes that has been lost. I find that I spool about 500rpm's less than before, but I have power all the way to 7200 rpms. And it feels like a turbo should...


See if anyone around you has a BT and get a ride.. Then find someone with a K04.. do the same...

See if you can drive them... The power delivery is different, but I dont think I would ever go to a ko4 even if I got a different car.. And I am an autox'er and I need to have the TQ way down low...

[djwimbo]

.. And I am an autox'er and I need to have the TQ way down low...

Same here. Though I think I may be moving into more "grown up" racing. We'll see what next weekend brings.

The K04 sounds tempting b/c it's a bolt on turbo. You can drive it around w/o any tuning if you feel like (just stay outta boost and high revs). Parts availability is great, you can still upgrade other stuff like manifolds, injectors, etc. and make some decent power.
I don't think I'd go with a K04 though. I'd lean towards the smaller GT turbos. That way you can have a smooth powerband throughout the RPM's and not a crazy spike. A medium GT turbo won't have a lot of midrange, there's some, but mostly top end.

That's my .02

EDIT: FWIW torque spikes like the K04 will produce make drifting in the snow a lot of fun. It also sucks b/c there are times when it's hard to control it, especially w/ some MBC setups. That thing is really touchy now that I got mine hooked up.

[nytoy]

Same here. Though I think I may be moving into more "grown up" racing. We'll see what next weekend brings.

The K04 sounds tempting b/c it's a bolt on turbo. You can drive it around w/o any tuning if you feel like (just stay outta boost and high revs). Parts availability is great, you can still upgrade other stuff like manifolds, injectors, etc. and make some decent power.
I don't think I'd go with a K04 though. I'd lean towards the smaller GT turbos. That way you can have a smooth powerband throughout the RPM's and not a crazy spike. A medium GT turbo won't have a lot of midrange, there's some, but mostly top end.

That's my .02

EDIT: FWIW torque spikes like the K04 will produce make drifting in the snow a lot of fun. It also sucks b/c there are times when it's hard to control it, especially w/ some MBC setups. That thing is really touchy now that I got mine hooked up.

Once you do a track days you never go back to autox, trust me!

Hmmm, so what's a good mid-sized turbo to look at? I kinda like the fact that the K04 is cheaper and fits in like stock.

[1fstavant]

go bigger i regret doing my k04 so much...it made 170 at the wheels and thats really pathetic....run an elim kit atleast, more than likely will be a little fun

[nytoy]

go bigger i regret doing my k04 so much...it made 170 at the wheels and thats really pathetic....run an elim kit atleast, more than likely will be a little fun

Yeah I saw the groupbuy, how fast the the elim spool though?

[mike-2ptzero]

Same here. Though I think I may be moving into more "grown up" racing. We'll see what next weekend brings.

The K04 sounds tempting b/c it's a bolt on turbo. You can drive it around w/o any tuning if you feel like (just stay outta boost and high revs). Parts availability is great, you can still upgrade other stuff like manifolds, injectors, etc. and make some decent power.
I don't think I'd go with a K04 though. I'd lean towards the smaller GT turbos. That way you can have a smooth powerband throughout the RPM's and not a crazy spike. A medium GT turbo won't have a lot of midrange, there's some, but mostly top end.

That's my .02

EDIT: FWIW torque spikes like the K04 will produce make drifting in the snow a lot of fun. It also sucks b/c there are times when it's hard to control it, especially w/ some MBC setups. That thing is really touchy now that I got mine hooked up.

Problem with going K04 is that they are very hard to find and when you do find them the price is nearly the same as going with a GT turbo.

[nytoy]

yea im having trouble finding a deal on a ko4, but the elim kiyt dynos ive seen look like power comes on 1500rpms later

[djwimbo]

yea im having trouble finding a deal on a ko4, but the elim kiyt dynos ive seen look like power comes on 1500rpms later

A GTRS eliminator will spool similar to it's more mature brother the GT2860RS. A high flow manifold will help get them closer to the same. From what I hear the eliminator will spool later as it's flow characteristics are different, but most of the faster 1/4 mile cars on the GT28 frames run an eliminator.

You're talking a good solid power band like a SOHC/DOHC V8. Low end it has some grunt, but midrange and top end she breathes. Obviously the larger the turbo the higher the powerband.

I just about dropped the cash while I had it for the 034 introductory offer of the Elim. kit. I'm glad I didn't b/c it would've cost me more to start over and go with a "real" setup. They'll be getting my business either way, but for the purpose I want, the elim wouldn't cut it.

Not a lot of people do it, but the GT25 can make an ok powerband with good midrange pull. The GT28's offer a lot more top end w/o sacrificing the midrange too much. I'd look into that route.

[mike-2ptzero]

yea im having trouble finding a deal on a ko4, but the elim kiyt dynos ive seen look like power comes on 1500rpms later

Yes, but it also keeps pulling 1500 higher in the rpms and produces 90-100 more whp.

[andyrew]

Yup my powerband is 3500 to 7200. I still get a good amount of boost lower, and even in 5th gear on the freeway I have way too much boost even at 2800rpms to make use of it so my boost controller is set to restrict it. in that low mid range.

[nytoy]

Not a lot of people do it, but the GT25 can make an ok powerband with good midrange pull. The GT28's offer a lot more top end w/o sacrificing the midrange too much. I'd look into that route.

The APRIII turbo kit, while expensive at $4400, looks to offer great spool up and plenty of low and mid range torque and plenty of high end breathing, I believe they are using a Garett honeywell turbo, I dunno if that is the GT25 you are talking about or not, but I think that might be my long term goal if I cannot find a K04 for cheap.

[mike-2ptzero]

The stage 3 uses a GT28r which used to be a GT25r. It is only going to make around 225 whp, which isn't all that much more then a K04. It is a night and day difference between a GT28r and a GT28rs.

[nytoy]

The stage 3 uses a GT28r which used to be a GT25r. It is only going to make around 225 whp, which isn't all that much more then a K04. It is a night and day difference between a GT28r and a GT28rs.

Is there any way to piece this kit together? It seems the manifold is amazing and tough to find. I'd love it for cheap

[Mcstiff]

With all of this concern about "no" power down low, has anybody compaired BT (or BAT) HP & torque curves to stock? Will you really end up with less then stock power below 3-4k RPM?

[mike-2ptzero]

With all of this concern about "no" power down low, has anybody compaired BT (or BAT) HP & torque curves to stock? Will you really end up with less then stock power below 3-4k RPM?

The only difference will just be tq below 3k. Hp is going to be the same or higher for the BT/BAT setups at 3k-4k. Even my BAT setup makes 130-150whp at 4k.


Here is a dyno with stock, chip and BT.

[andyrew]

Ya my car feels very similar to the way it was before with the chip below 3.5k. After that the boost just keeps coming and the power keeps coming on stronger and stronger till redline the way a turbo car should be (actually I often find myself hitting the rev limiter at 7.2k).

[docurley]

There is always the Scroll SP51 Outlaw conversion for the K04-15 which specs up higher than a K04-23 (TT turbo) which I have going on the car on the 8th Sept then at the end of the Month I'm hopping to get it mapped.

Friend of mine fitted his with all stock parts bar exhaust and got 243bhp & 275 torques after a remap.



http://www.audizine.com/forum/showth...highlight=sp51

[nytoy]

There is always the Scroll SP51 Outlaw conversion for the K04-15 which specs up higher than a K04-23 (TT turbo) which I have going on the car on the 8th Sept then at the end of the Month I'm hopping to get it mapped.

Friend of mine fitted his with all stock parts bar exhaust and got 243bhp & 275 torques after a remap.



http://www.audizine.com/forum/showth...highlight=sp51

I would love this if there was a tuning file out for it. It seems like K04's are rare now anyways.

[mike-2ptzero]

243bhp is only 189 awhp, not exactly all that great.

[docurley]

243bhp is only 189 awhp, not exactly all that great.

Well great is an opinion but is it what he is looking for I think yes and one advantage with this setup is he can buy a cheap dead K04 and have it upgraded or have a K03s turbo upgraded to K04-15 spec for not a lot of money and have a turbo which is like new after.

[AudiA4_20T]

just get PC16 and be done with it

[t1demont1]

Just peice together a 28rs kit. Youll be more happy with it in the long run. a k04 is a joke when it comes to power in my opinon since it still doesnt do anything in the higher rpm range

[offroader1006]

K04 is a great turbo, if you obey speed limits.

if you want to go over 65, it runs outta umph.

[mike-2ptzero]

K04 is a great turbo, if you obey speed limits.

if you want to go over 65, it runs outta umph.

Well the funny part is that the K04 is only better for tq when under 3k-3500 rpm.

[nytoy]

Just peice together a 28rs kit. Youll be more happy with it in the long run. a k04 is a joke when it comes to power in my opinon since it still doesnt do anything in the higher rpm range

Yeah I love the APRIII kit and torque curve on that, if I can find a kit used I'll go that route, otherwise I may just keep hunting for a K04 used. I missed the one in the classifieds by a day last time, still kicking myself. If money weren't a problem I'd buy a 28rs kit in a second.

[1fstavant]

k04s are a waste of money! plain and simple. go big or go home...in the long run your gonna spend more money then necessary because ull always want more...

[Kaytek]

Curiosity killed the cat... but I've got to ask. Refering to the dyno plot mike-2ptzero posted on page 1 (link for the lazy), would a GTRS with an 034 high flow manifold, high flow cat, larger down pipe and all that good exhaust stuff as well as a larger turbo inlet pipe be able to begin to spool at such low rpms? From the plot, it seems like only a 500 rpm difference between the GT28RS and K03 which would be nice since I've got a Tiptronic.

Also, if I wanted to get 300ft.lbs at the crank, would a GTRS be able to produce a more flat torque curve if it wasn't trying to produce its max torque?

[crono35]

I bought the K04 i have because I found it for a great deal with the PC-16 kit. It passes CA smog with almost everything in place (i swapped out my FMIC, but i've heard it's legal to leave it there as well).

It's no rocket ship, but for a daily driver I won't complain. Good for street driving, not so much for 1/4 mile runs. It's kind of how the car should have come from the factory, both performance wise and stock engine looking-wise. Here in Irvine I want to give cops as little reason to hassle me as possible :)

[mike-2ptzero]

Also, if I wanted to get 300ft.lbs at the crank, would a GTRS be able to produce a more flat torque curve if it wasn't trying to produce its max torque?

Yes.

[Kaytek]

mike-2ptzero: Would you happen to know if there is a large difference between the GTRS and GT28RS in how fast they spool up?