Just thinking ahead, just in case I can, turbo question

[macspring]

K26/2871 Turbo - http://www.034motorsport.com/turboch...ger-p-321.html

RS2 Replica Injector - http://www.034motorsport.com/engine-...set-p-369.html

Was just wondering what people thought of these two, in particular the turbo for an Avant that is driven everyday in stop start traffic and where early spool and torque are paramount, as is the ability to bolt it all together myself with some Wagner pieces.

I wanted handy off the shelf with no complications, and good / easy compatibility.

Don't really want to have to open it to change the rods, but.....

Also is there a seller for the turbo on this side of the pond that people would recommend?

Thanks in advance for any feedback either way.

[Jamo]

2871 is more about bhp than torque should hit 400 bhp with it, it's standard rod friendly ( Repo & Kalske had 458 bhp out of a 2871 setup ).

I'd say go for the siemens 630cc Deka injectors instead of those replica injectors.

It's not an off the shelf fit, you'll need new water and oil lines to the turbo and you may need to modify a few things to get the turbo fitting correctly.

Price in UK will be more expensive Europe side, best of buying it from ATP or 034 for value. Else your looking at places like Owen Developments and AET turbos but you'll pay 1k or more

[DamianURS4]

I bought these injectors as part of the whole RS2 bundle (chips too etc) and tbh I would agree with Jamo on the injectors - the whole bundle seemed not to deliver the 360-380 bhp and the injectors seemed very 'small'. All I can say is that they delivered good mpg but at the expense of perf. Green tops sorted the flow rate (and Hoffers chips did the rest)!

[prj]

Don't think you will be able to run 630cc on motronic and have it idle properly.
At least I have not found out how yet, maybe someone smarter than me knows how though.

[GazzaG60]

id speak to paul at the boost factory.

[Jamo]

Don't think you will be able to run 630cc on motronic and have it idle properly.
At least I have not found out how yet, maybe someone smarter than me knows how though.

The siemens should be o.k as the injector open times are lower and the spray patterns are very good

The type of injector used makes a big difference, an injector is not just an injector as I have found out.

[prj]

The siemens should be o.k as the injector open times are lower and the spray patterns are very good

The type of injector used makes a big difference, an injector is not just an injector as I have found out.

Motronic 2.3.2 will run pig rich at idle with 630cc injectors and no amount of tweaking the fuel maps or krkte seems to help.
This is either a limitation of Motronic or there is a minimum injection time constant somewhere, that I don't know.
The injector has nothing to do with it, it's the flow rating that is the problem.

On a standalone this won't be an issue. Or perhaps a tuning company who knows M2.3.2 better than all active posters on this forum knows how to reduce the injection time.

[macspring]

So to take this future thinking/hoping a step further forward,

what do people think of the following spec. and of the likely bhp, torque, point on the rev range at which it will boost, and any other pertinent points, for an Avant city daily driver ?

1. RS2 air box
2. Wagner RS2 Evo front intake intercooler.
3. Wagner RS2 front intake manifold.
4. Standard throttle body, (i.e. not bored out by 034)
5. Standard Head and Cams
6. Rods - Std or uprated.
7. Pistons standard.
8. Fuel Injectors?
9. RS2 turbo refurbished/tweeked or one of Hoffer76's K24s with RS Focus part. ( ).

Not sure about the turbo mentioned at the start of the thread after reading the subsequent replies before this post.

10. Wagner RS2 Evo cast exhaust manifold
11. Second hand RS2 downpipe.
12. Second hand RS2 exhaust system or a miltek RS2 new one
13. ECU ?

as Shane says live mapping of std ECU or aftermarket ECU over here might be an awkward step due to, who's to do it?

14. Probably Samco boost hoses. N-75 is new, plugs and plug boots are new, pos seem fine with current spec of std with homefry. Mileage 120k +, with original S2 bearings, std crank, std bov, std dm flywheel, std front pulley, new std toothed crank wheel for the new belt, new oem water pump, std oil cooler.

Sure I've forgotten to list something, but as per the beginning of this post what do others think?

One other thing, can someone explain the correspondence between fuel injectors rated in lbs and cc, and I can't grasp the match between the two different scales of measurement?

e.g. 630cc and say 42 lbs

Thanks for your time/patience.

[prj]

1. OK
2. OK (but there are much cheaper options)
3. Not needed with such power levels, waste of money.
4. OK
5. OK
6. Standard is OK
7. OK
8. 360cc or 440cc
9. RS2 turbo or K26/K27 hybrid
10. OK (but there are much cheaper options)
11. OK
12. OK
13. If it is a street driven car, I can't justify a standalone at this power level.

what do people think of the following spec. and of the likely bhp, torque, point on the rev range at which it will boost, and any other pertinent points, for an Avant city daily driver ?

1. RS2 air box
2. Wagner RS2 Evo front intake intercooler.
3. Wagner RS2 font intake manifold.
4. Standard throttle body, (i.e. not bored out by 034)
5. Standard Head and Cams
6. Rods - Std or uprated.
7. Pistons standard.
8. Fuel Injectors?
9. RS2 turbo refurbished/tweeked or one of Hoffer76's K24s with RS Focus part. ( ).

Not sure about the turbo mentioned at the start of the thread after reading the subsequent replies before this post.

10. Wagner RS2 Evo cast exhaust manifold
11. Second hand RS2 downpipe.
12. Second hand RS2 exhaust system or a miltek RS2 new one
13. ECU ?

as Shane says live mapping of std ECU or aftermarket ECU over here might be an awkward step due to, whose to do it?

14. Probably Samco boost hoses. N-75 is new, plugs and plug boots are new, pos seem fine with current spec of std with homefry.

Sure I've forgotten to list something, but as per the beginning of this post what do others think?

One other thing, can someone explain the correspondence between fuel injectors rated in lbs and cc, and I can't grasp the match between the two different scales of measurement?

e.g. 630cc and say 42 lbs

Thanks for your time/patience.

[S2central.net]

I did get a 2871 working on Siemens 630cc injectors and AFRs were OK... it wasn't pretty how I got there, but that turbo can seriously chew through MAFs when let to run to full chat - circa 420bhp was the estimate from G-Tech runs on a hefty URS4 avant.

Have a search for fuel injector calculators - I have my own spreadsheets and stuff for that - cannot remember the exact method but its simple science - you need to know the density of petrol to convert from volume to mass. The reason its common to rate injectors in terms of mass of fuel is because air flow meters measure the mass of air - and many turbo firms and tuning companies generate data in terms of lbs - which also comes from volumetric efficiency of engines that relate air flows in terms of cubic feet per minute - again you need to know density of air (at prevailaing pressure & temp) to convert from CFM to lbs / minute.

The maths are funky but a good reckoner for the I5T engine is that if you want to hit X00bhp then you need a fuel injector that is rated for X00ccpm at 3bar - so a 370cc injector on RS2 is comfortably good for 370-380bhp when running at 4bar. Its not perfect science but its a good reckoner for our engines.

I gotta say that an RS2 or small hybrid is hard to beat for reliable daily driving action with plenty of capability for the occasional bit of overtaking fun. Stick with stock cams & bottom end - no need for exotic rods unless seeking very high torque levels but even 550Nm on modifed RS2 setup will not ruin stock bottom end. RS2 injectors (or 034 replicas) are fine for up to ~380bhp IMHO. Probably could squeeze a little more out of them but why take everything to the limit on a daily car ?

[prj]

at 420 hp the MAF will indeed be a problem.
A problem that can be solved by using a different MAF...

[s2_wot]

David,
What's the plan powerwise? 300, 350, 400 or more?
The question I have is without going for a stroker where do you strike the optimum balance between smooth power delivery, drivability on a daily basis, reliability and cheap maintenance?

[T2Andy]

I did pretty much what you are wanting regarding tuning choices
This is on a aby car
Rs2 ex manifold
Rs2 hybrid turbo ,smaller hot side
Rs2 injectors
Rs2 air box
044 f/pump
Supersprint dp exhaust
Mtm rs2 ecu
And the head has had some work ,this lot made 335bhp and lots of torque
Testing against other cars it pulls alot harder than an rs2 and makes a chipped s2
Feel tame ,the midrange is amazing power tails off about 5500rpm ,I think a custom map would produce more though ,very drivable but awesome when you need it .
Although you can't use all it's performance very often I'm still wanting some more now after 12 months

[macspring]

Thanks for the replies,

Shane, less than 400, but also as much of the current boost/future boost as early as possible.

The Fry is great, and transforms a std car, but a liittle more is always nice. Look at T2Andy's comment. I blame the forum myself.

It then appears to me to get comparatively much more expensive to reach over 300 and get to say 330 / close to the 400 mark, than to go from 230 to 280.

@ prj - While front intake manifold and matching intercooler may seem excessive/expensive, I was keen to reduce lag, future-proof it and bolt on a quality tried and tested solution. I'd agree there are cheaper, but sometimes you can get what you pay for and as it is a daily I'd like to fit easily and forget, as time and time off the road is an issue for myself, especially after the carry on as per my signature.

Same reasoning applies to the choice of the Wagner exhaust manifold.

Relieved and concur with your reply re the ECU.

Notwithstanding my comments above, I appreciate your observations and feedback.

Thanks Paul for the injector feedback, I'll ask you to paraphrase that in English when at the meeting next Thursday.

Kind regards.

[T2Andy]

He's saying your injector cc will be roughly the same as the bhp ,ie use a 440cc inj if 400/440 bhp is achieved or expecting this seems to work on our engine config 2.2 5cyl.