Turbo installation - Now complete
Turbo Mini Forums

In fact there was only 6 A series cars made of which I think only one other is road registered

Edited by matnrach on 20th Apr, 2008.

Looks great! :)

After many iterations, the engine is finished.

Latest mods have included a large port 36mm inlet/31mm exhaust head (still around 9:1 CR)
Old 544 cam has gone and a Kent 266 fitted
Turbo oil pump, grey clutch, ARP bolts, increased capacity charge cooler pump, inlet manifold mods to redirect idle air, a wiring tidy up and increased boost.
Quite a lot of mapping to do as the old cam had loads of overlap and charge rejection.

(can't seem to post an image - I will add in the car section)

Edited by matnrach on 20th Mar, 2010.

What management are you running on this mate?

Its Megasquirt 1 V3

Its been a while since I posted here.
The engine has undergone quite a few changes as well as the gearbox which is now of the SCCR type after a third gear failure
The original hybrid T2 turbo was great top end but did lack low end torque so decided to downsize as most of the time is spent below 5000rpm
Found a suitable ball bearing unit which has just been fitted and it certainly has improved matters
Peak boost, now at 1.1bar is achieved 1000rpm earlier and the pick up is stunning
More mapping to do but first impressions are very encouraging.
From the compressor map it looks like I will be on the limit of wheel speed so I will try and measure it soon
Also just gone bluetooth with the ECU and using Shadowdash which works really well for early in its development
Here is a quick pic of the installation so far..

The MS apps are really coming along arn't they, cant wait until stuff can be tweeked via phone.

what turbo are you on then? I didnt think there were any BB units under GT25?

Hi again.
The turbo is actually a ball bearing IHI unit but I found that the wastegate was a little too small and overboosted slightly at high revs. However I opened it out a bit too much and then it didn't seal..

I could have got another turbine housing but thought I'd just put an external wastegate on instead. More work but better sealing and control.
Well after a little work on how to set it up using open loop control at the moment, it works really well.
Very happy with the turbo as it gives really good all round performance and response although it strangely needed a lot of work on the fuel mapping. This is the installation at the moment.

This is not helping my recently found plastic fetish...

Impressive!

Great work.

After knocking round in the Nimbus for a few hundred miles, My thoughs have turned to a new turbo. The T3 is such a dog. The IHI RHF4 on the Sprint is amazing in comparison. Is yours a 4 or bigger.

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

www.twin-turbo.co.uk

It is a RHF4 and it is so much better than my old T2 hybrid
With mapped boost control I can use all of the range of the compressor map safely

When does the rhf4 rj out of puff? Ballbearing turbos are the way forward. There is one on an iveco which is good for 280bhp and ballbearing.

Drives
-Ford S-max Mk2 Ecoboost
-Rover 100 VVC #2 - track project

Searching is all you need on TurboMinis

There are many variants of the RHF4 turbo.
The one I have used tops out at about 170bhp but gets to max boost well below 3000rpm transiently
I am using most of its range but it obviously gets a bit inefficient at the top end.
I am going to increase the charge cooling capacity to suit

You have the same version as me then. Mine is on a 998, but makes full boost before 3k also. The turbins is probably a bit small for big power.

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

www.twin-turbo.co.uk

Exactly. I specifically didn't want to make 200hp+ as it is intended as a road car only with the best possible response and wide useable torque
In fact its amazing how that T3 on the Metro was ever specified in the first place

I really like this!

can i point out a possible issue though,

the external waste gate that you've added could skew your AFR readings, boost pressure fed to the top union in your pic will leak past the stem of the poppet valve and into the exhaust ahead of the lambda sensor, could be part of the reasuon that you had to retune? did it need richening up on boost? keep an eye on what Mr Sparkplug says, and maybe trim the AFR table back slightly if it looks rich.

for an exhaust that length I would have been tempted to leave the dump pipe seperate, and if it was too noisy stick a small Bike silencer on it.

Hi,
The fuelling was off before I fitted the external wastegate. Maybe a function of the difference in back pressure during overlap? Not sure but its fine now. Adding the wastegate made virtually no difference

The pressure feed to the watsegate has virtually no flow anyway its just a pressure signal. But I am bleeding some boost pressure off to the bottom of the diaphragm so yes there will be some flow but very small

I really didn't want a screamer pipe. To tie it back into the exhaust was relatively simple.
The silencer is basically from a bike anyway with the internal perforated tube a bit larger in diameter

Edited by matnrach on 16th Feb, 2013.