My stage 2, 998 A+
Turbo Mini Forums

This is my stage 2.

Remember my stage 1, it was not performant. I wanted more.

Externally the car looks as before.



Sorry officer I could not be caught at 100mph, it's an all original car.
Well, seats are from a Mayfair.
Under the hood ?



Sure I installed injection, it's good for environment.
All these hoses ? I've got two rads, you know these old engines overheat on hot days. Yes it's nice in blue.



Why all these instruments ?



I like to know what happens:
- oil pressure
- oil temperature
The third one ? It's aaah the pressure, aaah, of you know, aaah, air pulsations ahead the throttle.
I've got the richness, to tune for environment.
Why it's written "turbo timer" ? Well it's actually used to control a small water pump when the engine is shut down, to let it cool down. It's named "turbo" ha-ha but it's not for turbo, do you see any turbo ?






Under the hood keywords:
- std balanced 998 A+, rev limiter set at 6500RPM
- 15W50 full synthetic bike oil
- not modified g295 with Minispares bronze guides
- MD266, lightened pushrods
- oversized exhaust, Rimflow intake valves
- ball-bearing RHF4 from Legacy twin-turbo (oops, did I say "turbo" ?)
- 1bar max
- hidden I/C (from Maserati biturbo, in place of the original water rad)
- Bosch Motronic ML4.1 ECU with my own firmware
- two Siemens 65lb injectors, 4 jet nozzle
- static ignition
- phased injection
- front water rad (from Metro), 10" fan
- additional electrical water pump (Chineese on ebay) controlled by a turbo timer, sends water to the turbo after the engine is stopped

Still few things to finish/improve.
Installed a huge modern rear view mirror from Maserati biturbo, that's a BIG change !

Still have to PowerDyn it.


Added on 19/09/2016:

Here is my old (2012) web page that explains many aspects of my engine management:
http://apavlov.pagesperso-orange.fr/mini/mini.html
And especially this one:
http://apavlov.pagesperso-orange.fr/mini/e...ine_stage2.html
with
http://apavlov.pagesperso-orange.fr/mini/e...management.html

Edited by alpa on 19th Sep, 2016.

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

At least it is unlikley that a Gendarme knows what a "normal" mini looks like under the bonnet.

The fact that you write your own firmware is very impressive.

You could be getting around 130-140hp at 1 bar boost.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

almost exactly what I have built. good job of hiding everything. shoulod be an impeovement on the GT15.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Yes it's much better than GT15 which was going crazy at 4k RPM.
Paul, I don't think I will reach 140hp. Because injectors are too small, because I have the std bottom (would not play with ignition too much), and because I'm scared to destroy the std transmission/gearbox.
The RHF4 works very well, I've got few PSI of boost from 2k but it really starts pushing at 4k, very similar to yours. From 4k I always have 3-5psi ahead throttle even in light loads. Rev limiter comes quite easily in 3rd, I put it higher once again, at 6500 this time.
I'll probably limit boost to 900mbar to make it safe. I'd like to avoid the oil cooler, no room.
Being the master of the firmware is very helpful when things don't work as expected.

Edited by alpa on 26th May, 2010.

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

900 Bar YOWSA!



Looks like a real sleeper

1/4 Mile 14.3secs 96Mph Terminal 10psi of boost.


Fibreglass Parts? - http://www.tdkracing.co.uk/
Split Rims? - http://www.force-racing.co.uk/

On 26th May, 2010 MikeRace said:
900 Bar YOWSA!



Looks like a real sleeper

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

sounds a good spec ...... the Standard head is the bottle neck here with those over size valves

i did the one on wil-h car for him which helped with some spectacular results

Fastest 998 mini in the world? 13.53 1/4 mile 104mph

Oliver's Mount Modified Production upto 1400cc Hill record holder
Thorseby Park Sprint Modified Production upto 1400cc course record holder

Impressive! Im a big fan of 998 turbos and this has deffinatly given me some more inspiration for my own. :)

Benross, it's a g295 head, it's green :) .
mcalvert, the 998 is definitely the right engine for FI, it does not ping, is very strong and cheap. Just do a well balanced cooling. I would love to try a 8-9k bottom (forged pistons and the right crank) with say 731 cam and bigger turbo. If I break this one this summer on the track I'll do that.

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I was really thinking of going up to 8-9k, to make something different. And go back to a not phased injection, just a stupid pair of MPI injectors firing like one SPI injector. At idle only one would fire, to have a more precise control.
With the poorly designed exhaust the head VE would start being a problem at high RPM. The best would be to make a nice 3in1 manifold.
And use a hybrid turbo with a very small turbine and a big external wastegate, to get boost from 2-3k, like on WRC engines (600Nm at 3500RPM on 2L).

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Yummy !

You have a turbo box if I recall correctly ?

If not, what was your manifold design like ? (again ?)

I have not been able to find more details on your cooling mods (inserts in the head to make it flow less on 1,2 cylinders and leave some cooling for cylinders 3 and 4)

Would you have some pictures or a sketch (because I want to copy it for my build) ?

Rusty by nature

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

I think you may be right.

A bit of an update; it will make 10psi in 3rd and 4th but only above something like 4300rpm. also it seems randomly to make 15psi in 3rd a lot lower than this at 1/2 throttle.

I think the wastegate could well be the problem. I'll poke around later.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

The other reason is that having a big turbo compared to the engine size makes it a bit tricky to make it spin fast. I gonna work on that this evening, I just finished the air duct for the I/C so now it should run colder. I'll see if I can improve the turbo response time by playing with advance and richness.

Advantage, I've got some pictures, will put them here.

Edited by alpa on 9th Jun, 2010.

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

wil_h, are you sure of accel enrichment ? If accelerating quickly does not work the same as accelerating slowly this may be the reason. Don't know if you use EFI, would be the spring stiffness with the carb I guess.

Edited by alpa on 9th Jun, 2010.

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

Not sure of fuelling at the moment. I had to give my VEMS up for a few days. I knew the fuelling was safe, but needs work. should have it back at the weekend for another play.

Right now I'm sure it'll get me to classic Le Mans though.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

Well this is how the water passages in the block were modified:


I've never been able to make ping the engine, or at least I don't here the knock through the knock sensor.
In the stage 1 I did not have bypass on the head. The engine was 80C with a 88C thermostat and front mounted rad.

In the stage 2 I have the cooling bypass with a 4mm restrictor. And water going through the turbo. All that seams to decrease the flow through the rad so the engine heats a lot in idle.
Now I think I should reduce the bypass to 3mm. I also have a restrictor in the turbo path.

Edited by alpa on 19th Sep, 2016.

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

Why have you done that to the water passage ways?
As for the restrictors, whats the idea behind that one? i can only see it increasing pressure rather than flow?

I presume that it is all about making the temperature across the block more even. rather than it getting progessively hotter from 1 to 4. Clever idea.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

The idea I'm not the first to have. It's a common place but on most of engines it's done with obstructed head gaskets.

Restrictors make water go to the rad instead of bypassing it through the bypass and turbo. When the flow is low water goes through the rad too slowly so engine temperature raises quickly.

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

Where and how did you fit your knock sensor ?

What is it of ?

I have been told they are dedicated to the engine (engine capacity and location) but maybe that was bullsh#t ?

Edited by Advantage on 10th Jun, 2010.

Rusty by nature

That was bullshit :) .
They are all more or less the same. What will depend on engine is the filtering frequencies the electronics need to identify the knock, it depends on the bore and chamber characteristics.
We as humans have some advantages over electronics to classify sound.
I fixed the sensors where the alternator's bracket is mounted on the engine, it's on the block and still near to the head. To listen knock you want to be as close as possible to the head but the head is very noisy because of valves, so you want to stay on the block. Ideally between cyl 2 and 3, to be closest possible to all cylinders.
Then just connect the sensor to an amplifier (an old walkman in my case) and listen. Hard knock is noisy, you can not miss it. Miata tunners listen to it form the car with open windows while driving :) .Light knock sounds like matches you'd break.
Above some RPM (say 5000) you'll be flooded by the engine noise, likewise the electronics. But there are less knock here than at 3000.

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm