GTX 3071 .63 v KKK26/27 # 6

[DJones]

I have had 2 B5 RS4's. Great cars but they like all cars do have there draw backs..

Someone mentioned they feel light, I didn't think so, the steering lacks feel and the clutch pedal, even with a new clutch, is heavy for our traffic filled roads...

My Ur (ok not an S2) with a GT3071.82 has less lag as does my 996tt. Don't get me wrong the RS is a great car hence I had two.. But they somehow feel very fragile to me.

The handling was good and you could get nice and progressive power slides without it biting back..

All in all you can't really compare the two cars....

[Rocco]

I have had 2 B5 RS4's. Great cars but they like all cars do have there draw backs..

Someone mentioned they feel light, I didn't think so, the steering lacks feel and the clutch pedal, even with a new clutch, is heavy for our traffic filled roads...

My Ur (ok not an S2) with a GT3071.82 has less lag as does my 996tt. Don't get me wrong the RS is a great car hence I had two.. But they somehow feel very fragile to me.

The handling was good and you could get nice and progressive power slides without it biting back..

All in all you can't really compare the two cars....

I'm also wondering why none tune avants for rallying or as track cars when does with coupes....

[prj]

Stock suspension is bad but if you fit some nice suspension the coupe must be Better.less weight,better aerodynamics.....

Of course a stock rs4 has to be far faster than stock s2

I don't care what you do to your suspension, to get to to RS4's level of grip/handling you will have to spend at least as much money as a RS4 costs, makes it kinda pointless, doesn't it?

Even Lloyd's RS2 which has an amazing setup, that is already a LOT better than your car when I was in it, has absolutely no chance against the RS4's bone stock suspension, let's just leave it at that.

I appreciate that the B5 will boost sooner, but was looking for a comparison of the GT3071 using the B5 RS4 as the benchmark. Had a go in a chipped B5 RS4 recently and it was better than I suspected it might be, given other comments of others on here who've also had a go in a B5 RS4.

There is no comparison. The RS4 has more of everything everywhere.
Why are you comparing what effectively is a 10 grand car with a 3 grand car? What's the point?
Only one thing I will say - it is much easier to make really big power (i am talking 800 and up) on a 2.2T than on 2.7TT. But drivability wise, it's like comparing a V8 to a 4 banger. This is also in part due to variable cam timing on the RS4, newer turbo design, less choke due to only 3 cylinders flowing through each hotside and so on.

If you are asking this because you are wondering if you should do the upgrade or buy an RS4, then buy an RS4, but only if your wallet is DEEP or you are prepared to learn about a LOT of things and do many jobs yourself.

[macspring]

Is there anyone on here with a RS2 hybrid turbo on their RS2 spec engine and if so how do they find it ?

Lag, economy, power, pleased, regrets, if only, if I was to do it again I would ....etc.

Thanks.

[prj]

Mapped a couple of them. Exactly same as a RS2, but has more up top.
Full boost 3600 rpm in 3rd. Lloyd has a chart as well, as he ran that turbo for a while, but is now much happier on a K26/K27

Link to Lloyd's old setup, incl. dyno chart:

http://prj-tuning.com/?p=48

If you want the same, but with a bit more power, go GT2871R with 0.82 A/R hotside.

[macspring]

Dimitri,

Do you mean in this order listed below ?

1. RS2

2. RS2 Hybrid

3. KKK26/27 #6

4. GT2876 .82

5 ?


btw, while a custom chip from yourself would naturally be the preferred option, do you have an off the shelf chip for any or all of these five turbos that could be used in the ABY Avant say up to 5k rpm, until I was able to arrange to meet up with yourself ?

Thanks.

[prj]

No particular order...

But IMO there is no reason to run 0.63 A/R hotsides on these cars at all.
It will just surge like hell and mapping it out you lose most of the advantage.

So go down a size. Instead of 3076/0.63 think 3071/0.82. Instead of 3071/0.63, 2871/0.82 etc. The 0.82 hotside is very good on the Garrett turbos as they are more surge prone than KKK's.

Ultimately if you are going sub 450hp, there is absolutely no point to do an engine build.
Giant waste of money for nothing.

If you are doing forged rods/pistons (no reason to run forged pistons except for lowering CR) then putting anything smaller than a 3076/0.82 on there is just dumb. It's like taking your cash and burning it in a fire, getting nothing for it.

So IMO either stock engine, stock everything with a better EM, exhaust and IC plus a sub-450hp turbo OR all out and then at least aim for 500+ with 700nm+.

[macspring]

It's just as well you are not beside me so, as you would clip me on the back of the head, as the engine is fully "built" by JP and in the car, just looking to decide on the turbo. Driving the urS6 as the daily dog at the moment.

So yes, agreed some of the expense incurred could turn out to be unnecessary, but when rebuilding the engine anyway, I didn't want to have to touch it again, so did all of the items, the other rationale behind it was that each item while maybe not fully exploited would still contribute it's own little bit to the engine being that bit better that say one that was more oem spec. even if just rebuilt, not to mention just slapping say a GT2871 on a 160k mile engine, caning it everyday and hoping for the best.

The engine has everything done to it to take a 550bhp turbo, it has an 044 pump, but still the oem breather equipment, albeit new and clean. But this bhp level of turbo will not be suitable for a town / motorway sometimes, daily driver.

I accept and understand that some of the money spent on the engine may have been "wasted", but am keen to be able to dog the engine a bit, without having to fret over it's reliability / durability. Also it's nice to be able to squirt it now and again / here and there during a journey.

When the Avant is done and back in daily use, I'll take your advice on the urS6's engine, and do much less to it to curb the expense. It pulls great, never misses a beat, is dogged a bit, was dogged by the previous with no ill effects, but it is weeping a little coolant from the number three cylinder on the turbo side where the head sits on the block. Additionally, it is an auto so it would need to be made manual to have anything better than your current auto ANN engine chip, which makes for a very nice K24 7000.

Also have a second ABY Avant and it's engine needs to be put abck to ether to ABY chip spec.

Anyway getting off topic now.

What off the shelf chips have you got available for what spec turbos ?

Thanks.

[prj]

I don't really do off the shelf chips. I can give you something temporary until I can map the thing in person but that's it.

If you already have 2 other AAN/ABY engined cars, then what's the point of building an uber engine, and then choking it?
And actually, a 3076/0.82 is PERFECTLY drivable around town. You just drop 1 gear down.

Currently when you are driving, you just mostly use 1st to get rolling, then switch to 2nd.
Going from K24-7000 to 3076/0.82 is just that - dropping 1 gear down. You still get 2bar+ in first gear. You can change from 1st to 2nd (at 7300 rpm) and you will not go into a lag hole.

There is only one trick - keep the cams standard... I've tuned and set up 3 cars so far with this exact setup, and turbo and all owners are happy and at least one drives his mostly around town.

I would go even further to say that a 3071/0.63 or 2871/0.82 is a horrible turbo for town driving. In 2nd you have too much lag, so when the boost kicks in at 3600 rpm you will be doing like 55 mph if you rev it out, and if you don't you can never use the power.
And first gear - well if you are going to use first gear, you might as well get a 3076 in the first place.

Non-town-streetable turbos on 2.2L I5 start at a GT35R. Here you really just can't hit full boost in 1st and impossible without NLS to shift into 2nd without lag.
Anyone complaining about lag with ANY turbo smaller than that IMO just needs to learn to drive a manual gearbox car.

Only exceptions are cars which are very light.

[prj]

P.S.

I drove my UrS6 with K26/K27 around town with full boost at 3800-3900 rpm.
2nd gear was completely useless. I used 1st.

I drove a friends RS2 setup UrS4 when I mapped it. Full boost at 3500, but I still found myself going into 1st, because I went WOT at about 2500 RPM most of the time in 2nd (30 kph or so) and the car just did not go anywhere at all at those points.

And finally a very good friend of mine has a UrS4 in the same town as I, with a 30R on it. I drove that for 2 weeks at 30 PSI last summer while mapping it...
Almost exactly the same as UrS6 drive wise, but flies.

Of course truth be told, if you want to drive around town comfortably, then the RS4 is hard to beat. 2nd gear is amazing all the time, and can get you in trouble with the law rather quickly The best would probably be a chipped A4 3.0TDI though or dare I say a 335D.

[A80Avant]

@macspring

you are at the same place i was in around 2006 when i was considering what to do to upgrade my engine whilst it was getting serviced.

however you seem to want to have the best of both worlds ie: torque down low and a lot of power up high. That cannot be done very easily with the 2.2

You would either need more displacement (going to 2.5 or a whole new engine), or you would compromise.

Unlike what a lot of people would tell you, i found that key changes in the engine before reaching the decision on which turbo to use made a difference and put all those together helped.

1)If i were to do it all over again i would get the head ported with larger valves,but not overdo the porting as it leads to lag.

2)Use the RS2 EM if i were to go up to high 4xx hp levels, as it can cope and esp. if you are not going to be going to high boost above 6500rpm it should be fine. Having that EM tends to reduce lag.Use Wagner stuff if going for 0.82AR or larger turbos as they will hold better but the wider the EM tubes, the greater the lag sometimes.

3) Fit a 70mm throttle valve. It made a difference in my case of how the responce is on off boost levels. (many people will say it doesnt, i state my experience only)

4) Turbo choise is difficult. If money wasnt an issue, i would do a hybrid with Owen, something like close to HTA or GTX, with a 0.63AR as it would give a very pleasant early boost, BUT it would likely surge on higher gears. (Let me explain a bit on that: It will surge on 5th and 6th gear when you are at 2000rpm and put the foot down, as the boost would be reached at 2800 easily with 2bar and then it surges. You can adjust that at cost of lower gears or you could also put half your foot down, get 1.5bar which is respectable and then after 3000rpm put your foot down to get 2bar.... To me, i would easily keep on using 0.63ar on my turbos.


As you can see, there are still a lot of differences. So you dont have a choise other than being a passenger on several of the many cars that have all these setups to judge on your own. You are in a country that has so many owners with different levels of tuning, and im sure you will find the one that you like.

All the rest is just theory, and if you only go with that, its very likely that the choice will be wrong in the end

[prj]

2)Use the RS2 EM if i were to go up to high 4xx hp levels, as it can cope and esp. if you are not going to be going to high boost above 6500rpm it should be fine. Having that EM tends to reduce lag.Use Wagner stuff if going for 0.82AR or larger turbos as they will hold better but the wider the EM tubes, the greater the lag sometimes.

And the best would be equal runner tubular EM, such as this:

http://www.kkdmotorsport.com/kauppa.php?t=1270709143&k=1270679050

Many people here making over 700hp on it and it does not crack.

[Rocco]

I don't care what you do to your suspension, to get to to RS4's level of grip/handling you will have to spend at least as much money as a RS4 costs, makes it kinda pointless, doesn't it?

Even Lloyd's RS2 which has an amazing setup, that is already a LOT better than your car when I was in it, has absolutely no chance against the RS4's bone stock suspension, let's just leave it at that.

Yeah,my Audi 80 needed lots of work about chassis...and the higher the power,the more difference noticed .

But the coupe is another history.

Btw,can you explain how crazy is the people using coupes as track cars or rallying when the could buy avants that they are cheaper to buy '?

There are many examples of this,do you think that this people is stupid then and they didn't study it?


I'm not an expert if course,but those things makes me think about what you guys are telling about the avants.


Rear suspension better,ok I can understand it of course .but suspensión design is not all...if not,answer my question about the stupid guys who prefers coupes over avants to be more competitive.

[Avantus]

Can't really agree on the suspension difference between B4 Avant and B5.

The rear is already completely 100% the same, and the front has a great range for adjustment of camber, caster, and toe. With powerflex bushes for example you get
a very nice front end, and only the topmounts on the B4 are complete rubbish.

I've also got a 515hp stripped trackday B5 S4, and that the engine is much more
suited to that with virtually no lag is ofcourse a different thing. But suspension wise
I would be happy to work with the B4 setup.

[prj]

if not,answer my question about the stupid guys who prefers coupes over avants to be more competitive.

If you have this attitude that everyone except you is stupid, then it's kind of pointless to discuss an argument, now is it?
Avant S2 has better rear suspension and better weight distribution, it is actually a better car balance wise from factory.

Your argument of "if I spend 6000 EUR on suspension, maybe I get close to stock RS4 handling" is kinda pointless....
For 6000 EUR you can get a westfield, which will wipe the floor with both the RS4 and the S2 on the track.


And Avantus, I don't know maybe it is the complete package about the RS4, but I've been in quite a few RS2's and RS4's and IMO the RS4 is just much better handling wise.
Of course what is even better is a B7 RS4. Another league entirely.