what gives the most uumphhhhhhhhh

[Jonnybravo]

A straight K26 turbo are a very bad choice as they make less power than the RS2 unit and about 20bhp more than a K24 with a lot extra lag.

The hybrid turbo's of K26/27 or K26/27/29 are a better choice.

I'll have to speak to my mate as its one of the spares off his old 100 Avant, he replaced it with a RS2 turbo. There might be somethingj written on it or a stamp that will tell me more, I quite literally put the box he gave me straight in the garage and haven't looked at it since.

Regarding the AVCR though, from using them on others engines I would say they can make a massive difference, I need a new map sensor for mine as its been driven over but I'll get it in and let you know the results

[Jamo]

If it's off a 100 Avant it's a straight K26, don't bother with it mate, seriously

[S2central.net]

Utterly agreed here.... Vanilla K26 not good for the S2.

RS2 turbo is a K24/26 hybrid

[s2bug]

have one that my 3b used to have on it before I bought it ...

in the garage box of things ...

bring on the RS2

Any more thoughts on that Mr N re 3071 etc???

[S2central.net]

3071 and 3076 - both great options but really need stronger conrods for safety margin against rod bending torque potential of those at full boost... You are also into even bigger fuel requirements (and bigger/custom EM requirements too and need a meaty exhaust) at this level and actually beyond 450bhp you run the risk off ripping out your MAF wire. Normal workaround for that is to move the MAF to t'other side - or you go whole hog and throw it away along with Motronic brain and go aftermarket ECU.

All depends what you want and how deep your pockets are.

I can offer a generic upgrade on the RS2 for ~350bhp performance levels and a lot less lag - nothing like as high boost on custom MRC remap - but it will need a 3bar VMAP. Pure s/w upgrade if interested - will make benefit of RS2 intercooler and runs with your Bosch Greens on ABY 4bar FPR.

[s2bug]

3071 and 3076 - both great options but really need stronger conrods for safety margin against rod bending torque potential of those at full boost... You are also into even bigger fuel requirements (and bigger/custom EM requirements too and need a meaty exhaust) at this level and actually beyond 450bhp you run the risk off ripping out your MAF wire. Normal workaround for that is to move the MAF to t'other side - or you go whole hog and throw it away along with Motronic brain and go aftermarket ECU.

All depends what you want and how deep your pockets are.

I can offer a generic upgrade on the RS2 for ~350bhp performance levels and a lot less lag - nothing like as high boost on custom MRC remap - but it will need a 3bar VMAP. Pure s/w upgrade if interested - will make benefit of RS2 intercooler and runs with your Bosch Greens on ABY 4bar FPR.

RS2 turbo defo then as my pockets dont drop that far and also is an immediate upgrade that my mech knowledge will allow me to do ... phew... apart from the MRc lovin that is ... how much would your homefries be with bigger map sensor?

Thanks Paul

[GazzaG60]

good choice. looked at the pocket balance. youll be happy. peeps rave about homefry. never had one as i like mapping but that many people cant be wrong. ive seen a few homefrie graphs and they look good.

has anybody tried a boost controller with a homefry? faster response and no valve lift. i remember how good my s2 was with the standard setup and a EBC hitting and holding 1.1bar or so. it went really well.

[shark_90]

How do you sort the fuelling out with a boost controller?

[Jonnybravo]

If it's off a 100 Avant it's a straight K26, don't bother with it mate, seriously

The car was converted by himself, it was originally a non turbo avant.

He worked for Audi at the time and replaced the K26 with a RS2 turbo and said he saw very little gains, the engine was mapped by a reputable Audi tuner (I forget there name) The biggest gains he said they had was going from the K24 to the K26.

He did a lot of drag racing with the car, stock engine pushed to the max and it managed 40k before I spat a rod out.

When I'm next up the workshop I'll get the turbo and see if it has any markings on it
which may help with what it is as he doesn't know what it came off originally.

[Jamo]

Put it on then, I know I wouldn't put a straight K26 on an S2 and neither would the two most reputable ecu tinkerers on the forum

[GazzaG60]

you cant sort tyhe fueling with a boost controller but you can sort the boost. the N75 is pants. you can get faster, smoother and better hit and hold with a dedicated controller. basically the valve in the wastegate lifts unless you equal the pressure top and bottom. a proper EBC allows this.

to sort the fuel you need ECU. i used EGT and WB02 with my EBC and set it to run within the limits at all times. the standard ECU can do 1.1bar overboost anyway soo that level is within ecu standard tolerence.

my mate could get 350hp from a subaru with only fuel cut defender, AF defender which adds a little fuel and an EBC. done over 30 times never failed. the best subaru mod for low money. some need a new pump others not. living within the limit of the standard ECU with a little trickery. the turbos on earyl impreza are bigger than outs though. probly RS2 size.

dont get me wrong a homefry will add a better level of tuning and safety to this but i reckon in conjunction with a EBC it would be a great near standard setup.

id forget a straight 26 too. never tuned one but can see little over the 24/26hybrid other than lag.

[Jamo]

EBC is no where near as good as a homefry, as your not addressing the ecu ignition timing for instance and the homefry will give you better MPG than the standard map with 50-60 extra bhp.

[shark_90]

you cant sort tyhe fueling with a boost controller but you can sort the boost.

That's not exactly what I meant.. sorry. I meant how do you deal with the fuelling when you are using a boost controller that the ECU doesn't know about?

[Jamo]

ECU doesn't use boost to calculate fueling, it uses the MAF to calculate how much air is coming into it.

There is a tolerance to a bit more boost being added but the EBC can't optmisie ignition timing.

My advice is if you want to use an EBC is use it after having the car mapped not instead of having the car mapped.

[S2central.net]

EBC knows nothing of fuel and timing... All it does is manage the boost profile - generally with a sturdier / faster version of N75.

The reason that EBCs work at all is that the ECU uses the MAF as the primary means of determining how much air is being ingested - so if you hike up boost levels then the ECU sees more air, and along with throttle position info can pick ignition and fuelling parameters from the stock maps to cater for that. So that bit is OK up to a point. The point is this runs only from stock maps of course. Boost pressure still manipulates the FPR mechanically - which should align for the injector time at the measured air mass intake.

The bigger problem is that if the ECU still 'sees' boost via the MAP sensor then it will complain if the boost levels rise too high or too quickly and you get cutouts with an EBC set too aggressively. So the normal workaround / hack is to disconnect the boost line from the ECU so that it only ever sees ambient pressure and then stops having kittens about boost control... THIS is where you get into dangerous territory as the ECU is now completely unable to run its failsafe routines for when it thinks boost is too high, there is excessive knock or coolant alarms are active - you are completely at the mercy of EBC safety.

What I would suggest is the best thing for anyone desperate to use an EBC (for faster spool or funky boost profiles per gear) is to work with me so that I can create a boost chip which allows the ECU to see whats going on, without getting confused or interfering with EBC - but allowing it to at least retard ignition if it sees boost levels above a safe threshold. I would also encourage anyone using an EBC to look at anyway to feed it with an alarm signal to emulate Motronic in how it interacts with F76 on the ABY... Turning off high boost when water temp is too high for example.