S2 to RS2 Engine upgrade

[jean]

Hi guys. I live in Cape Town, South Africa and have recently acquired a 1991 S2 with the 3B engine. The intention is for my son and I to restore this car as a project which is exactly the same as the project by newsh on the forum. We want to reupholster the interior (seats, floor lining, roof lining, doors, etc) , fit larger brakes, fit upgraded suspension , add bling to the engine bay etc. These items are all available and therefore straight forward. Most importantly though we want to upgrade the engine to produce approximately 350Hp for now with the option of more power at a later stage if we want to. The car has covered 335000km so the engine will be completely overhauled. As we all know these engines can produce serious power well in excess of 350HP however we want the car to be drivable in normal everyday traffic as well as have the grunt when you want it to blow off some of the much younger performance cars and to enter the odd track day. Based on information on the forum it appears that the best, most reliable and simplest option would be to go for the RS2 upgrade. So with this in mind herewith a few questions that I have and would appreciate some help with. I am not a qualified motor mac so excuse any questions that may appear to be silly.
- Is the RS2 conversion genuinely a bolt on conversion?
- Wagner offer S2 and RS2 IM and EM, do I order the S2 or RS2 manifolds? (I would assume that it would be the RS2 components but I just want to confirm)
- Same question as above applies to the Wagner intercooler
- When fitting the RS2 intercooler, can the standard S2 bumper be retained or must a RS2 bumper be fitted to accommodate the larger intercooler?
- Is the piping, crossmember , and all necessary mounting brackets and accessories included with the new intercooler from Wagner or must they be purchased separately?
- What is the most suitable turbo (without too much lag) to fit and where can I source it?
- Is it necessary to fit the RS2 air box, will it fit where the S2 air box is fitted, can the S2 air box be retained but with a K&N filter or similar?
- Where do I source the metal head gasket?
- Exactly what size injectors should be used, or can the standard RS2 injectors be used? Where would I buy these?
- Will be fitting stronger con rods, any recommendations?
- Fuel pump, any specific one?
- I would prefer to retain the standard 3B ECU and engine management if possible but from info on the forum it appears that it can be problematic when doing this conversion, any recommendations?
- From a practical point of view I would like to retain the distributor set up however if it is not possible what does it entail to convert to coils etc. Does it require new looms, does any of the wiring have to be altered?
- Is it necessary to change the position/location of the battery?
- Must the clutch be upgraded or can the S2 clutch be retained?

I am sure that I have left lots important things out so I would appreciate any additional info, suggestions and guidance that anyone may have.

Thanks Jean

[S2central.net]

Welcome - thats quite a wish list and series of q's for a 1st post

Without wishing to sound rude or unfriendly you will find answers to evetything by searching the forum so it is best to take some time and read up on these topics.

To give you a brief summary response - yes you can pretty much bolt on upgrade from 3B to RS2 if you wish. The ecu and wiring needs changed for coilpacks etc but it's all been done before.

If rebuilding the engine then get RS2 bearings and metal head gasket. Wagner parts are great though expect some adhoc mods to cleanly fit their reverse IM into B3/B4 chassis.

I can help you with modified Rs2 ecu software that will give you 360-380bhp on rs2 injectors.

Lots of clutches exist for 3B single mass flywheel - sachs organic etc

You might find 3B gearbox to be weak point if car is driven aggressively for launches etc but its fine for normal driving.

[prj]

- Is the RS2 conversion genuinely a bolt on conversion?

Yes.

Wagner offer S2 and RS2 IM and EM, do I order the S2 or RS2 manifolds? (I would assume that it would be the RS2 components but I just want to confirm)

You don't need to change the intake manifold. It will give you nothing at this power.
As for EM, doesn't matter... they should be the same.

Same question as above applies to the Wagner intercooler

Again, should be the same.

When fitting the RS2 intercooler, can the standard S2 bumper be retained or must a RS2 bumper be fitted to accommodate the larger intercooler?

RS2 bumper allows more air past it afaik, but I think both intercoolers fit both bumpers.
I never did this job though, so I might be wrong here.

What is the most suitable turbo (without too much lag) to fit and where can I source it?

Either the RS2 turbo (K24-7200), or alternatively the Volvo S60R turbo (K24-7400).
The latter has a lot less lag, but will give about 10hp less than the RS2 turbo.

Is it necessary to fit the RS2 air box, will it fit where the S2 air box is fitted, can the S2 air box be retained but with a K&N filter or similar?

Keep stock airbox, keep stock filter.

Exactly what size injectors should be used, or can the standard RS2 injectors be used? Where would I buy these?

The standard RS2 injectors must be used for RS2 chipsets. Do not buy any "replica" injectors, they will never run right.
You can source them on this very forum, there are always people offering a set for sale.

Will be fitting stronger con rods, any recommendations?

Get rods from user Aronmatic on this forum. They are cheap, work well and have been tested by countless members on here.

Fuel pump, any specific one?

A few options.
a) RS2 fuel pump
b) Bosch 044
c) Walbro 255 lph
d) This one: http://cgi.ebay.co.uk/GS342-HRC-255-...item3a6654e450

I personally use the 255lph Walbro ebay replica. It is a japanese nippondenso pump, thus very reliable, it is silent (unlike 044 and walbro) and delivers enough flow.

I would prefer to retain the standard 3B ECU and engine management if possible but from info on the forum it appears that it can be problematic when doing this conversion, any recommendations?

The easiest and cheapest way would be to swap to the AAN Motronic, then get a tune for it.
There are instructions on this forum, on how to accomplish it:

http://www.s2forum.com/forum/showthread.php?t=51419

From a practical point of view I would like to retain the distributor set up however if it is not possible what does it entail to convert to coils etc. Does it require new looms, does any of the wiring have to be altered?

No, you only need to add a few wires for the coils, the wiring is generally the same, only a few pins swapped around in the ECU connector.

Is it necessary to change the position/location of the battery?

No.

Must the clutch be upgraded or can the S2 clutch be retained?

Personally, I've managed to slip every stock clutch I've mapped on RS2 turbo.
I don't know that much about 3B (single mass flywheel) but on AAN you usually fit a SRE pressure plate with stock disc for a streetable, but strong clutch.

I am sure that I have left lots important things out so I would appreciate any additional info, suggestions and guidance that anyone may have.

I am confused by the fact that you are ready to blow lots of money on different parts, but you would like to retain distributor ignition...
If you want RS2 setup on 3B ECU, that more than likely means custom mapping... which as I understand is not possible for you to get...

[quattrostyle]

Keep stock airbox, keep stock filter.

I'd like to disagree on a 3B, it's more restrictive than an ABY/ADU airbox.

[Rocco]

Got 3b to rs2 software for you if you want,

Reliable,fast,cheap, and for all the family

Also got a motronic with 300kpa ready if you need it.

I was using this for more than 2 years and 0 problems.

Nice Afr anf egts,at least on my car.

391hp & 644nm on a little optimist Spanish dyno

[Rocco]

I'd like to disagree on a 3B, it's more restrictive than an ABY/ADU airbox.

+1

Also got a new rs2 airbox for sale too.....I don't need it anymore.

[Ross]

..or you can get a cheap ABY airbox and mod it (threads can be found on the forum) with a bigger intake port.

[Tap Towers]

Ian4455 is selling some new good bits for a 3B..

Ive seen them, not even fitted they are that new.

[Rocco]

..or you can get a cheap ABY airbox and mod it (threads can be found on the forum) with a bigger intake port.

This is not the same....

Rs2 airbox has more interior room and the air intakes better!
If not,take the 3b box and do the same.....

[Ross]

This is not the same....

Rs2 airbox has more interior room and the air intakes better!
If not,take the 3b box and do the same.....

You're right it is not quite as good for that reason, but still bigger and better than the 3B, and alot cheaper! With a 4" inlet port the air intake has proven to be a good cheap alternate to the RS2 airbox.

Also - there is no mention of the main bearings, which I recall replacing on my 3B when I went higher power as they are not as strong as those fitted in the later engines.

[R31LLY]

fuel pump

http://cgi.ebay.co.uk/GS342-HRC-255-...item3a6654e450

is this the exact fuel pump required for the aby? just click and buy and it will fit?
also were is it located? under the rear seat??

[jean]

Thanks guys for the info. I'm going to digest all this. If we have...when we have more questions we'll be sure to ask. Will keep you updated on how the project progresses.

[Master]

Interesting thread this

[orsum]

Don’t forget to upgrade your brakes.

With the KW you are planning I would do the brakes first.

orsum

[UrS4boy]

Interesting thread this

You might want to consider this:

First of all you might want to read this bit of 20 valve inline 5 turbo history to bring you up to speed:

http://forums.quattroworld.com/s4s6/msgs/194362.phtml

From the above, you should see that the AAN and ABY are very similar except for the intake manifold configuration and that the ABY and the ADU in the RS2 are even closer.

With that in mind, I will tell you how I "RS2'd" my AAN in my 93 UrS4.

1. Change the exhaust manifold from the stock manifold to an OE RS2 exhaust manifold *OR* a Wagner RS2 EVO cast manifold. I went OE RS2 but I have a Wagner EVO to install some time. Here is some exhaust system reading for you:

http://forums.quattroworld.com/s4s6/msgs/196904.phtml

2. Change the turbo to an RS2 K24-7200 or the Volvo K24-7400 (some mods needed) or a Garrett hybrid GT2876 (or 2871) from 034. I went RS2 K24-7200.

3. Change the injectors to RS2 Bosch green tops or equivalent. You want to make more power? You need to flow more fuel at higher boost levels. I went OE RS2 Bosch. Here is some injector reading: http://forums.quattroworld.com/s4s6/msgs/20441.phtml

4. Change the Mass Airflow (MAF) sensor to a RS2 unit (or leave it as is, your choice). I went RS2 MAF. Here is some MAF sensor reading: http://forums.quattroworld.com/s4s6/msgs/20442.phtml

5. Upgrade your Manifold Absolute Pressure (MAP) sensor from 250 kPa (2.5 Bar) to 300 kPa (3.0 Bar) which, with the proper software, gets you boost levels into the 26 to 28 psi (1.9 Bar) relative range. I went VMAP (the adjustable version). Here is some MAP sensor info reading: http://forums.quattroworld.com/s4s6/msgs/20417.phtml/

6. Have the software upgraded by a reputable firm. This involves booth the timing/fueling chip on the top board and the boost chip on the bottom board. I went with MRC Stage 3 (generic RS2 plus). This makes about 289 wheel hp or about 360 crank. Other softwares can do a bit more. Pinking/pinging/pre-detonation becomes the limiting factor and is a function of the octane of the fuel you can get. Higher the better.

There are also ignition upgrades to consider but the above should be enough to get your litttle grey cells going, mon ami.