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Re: My Budget 300bhp St185

PostPosted: Sun May 22, 2011 7:48 pm
by MrDB
Plumbing now done

the Feed from radiator cap. the cap has had centre taken out so no pressure is held and the header tank cap now holds the pressure.


The header tank main return into bottom radiator hose.



Over all


Minimum parts list.

1 ) Header tank similar to above.

2 ) 8mm hose from rad to tank

3 ) optional 2 x 90 deg 32mm silicone hoses. ( you can just cut original bottom hose )

4 ) 32mm T piece 32,32,22mm 22mm is from header 32mm is to fit in bottom hose.

5 ) 22mm flexible hose for headr tank too bottom hose.

6 ) pipe and joiner to extend power stearing hose so you can relocate it.

7 ) misc aluminium / brackets to mount header tank / power steering.

8 ) hose clamps..

Re: My Budget 300bhp St185

PostPosted: Tue May 24, 2011 7:37 am
by MrDB
After running for a few days with header tank i can now say cooling does seem to have improved i now no longer have the glugging ( hot spot boiling ) noise from engine once engine is shutoff after a hard or long run.

So has some benefit.. :)

Re: My Budget 300bhp St185

PostPosted: Tue May 24, 2011 9:22 am
by aus jd 2703
ok i have the hot spot boiling issue and it bothers me so this mod interest me. just explain please the theory of a header tank i dont quite follow.
its a reservoir that's preassigned and lets air from the radiator out and out of the bottom hose allowing no air. is this right?

Re: My Budget 300bhp St185

PostPosted: Wed May 25, 2011 7:42 am
by MrDB
The stock high spot in the cooling system is the top of radiator this is almost the same height as head.

Buy adding the header you raise the high spot to above the head by about 1-2" and also adds about 1-2 ltrs of coolant into the system.

I also beleive the bigger head of water that feeds directly behind the thermostat helps stabalize water temps around it.

Once a swirl pot is added between head and radiator pretty much all air is self bled into header tank out of harms way.

It maybe a placeabo but i swear the car drives better now also, more responsive...

Re: My Budget 300bhp St185

PostPosted: Tue Jun 25, 2013 1:38 pm
by MrDB
Wow been a while since last update.

So here goes

Not the best pics but

Installed an Oil Cooler


Shorter belt for aircon removal


Aircon be gone


Oil cooler take off plate im running a remote thermostat.


Bigger brakes 312mm audi TT discs stock calipers. Stops like it should now. :)

Before :


After :


pictures testing on a mates st202



Tested on track and with stock setup i managed 1 lap of silverstone race circuit before no brakes on this setup i had zero fade after 5 laps.

Stock calipers are fitted to new brackets design below.

Just need spacers for studs. and HT bolts.

Found the caliper mount PCD which is 85mm

Stock disc is 277mm and new 312mm so bit of maths and thats
35mm bigger / 2 and thats 17.5mm

So add 17.5 mm to 85mm and new caliper pcd will be 102.5mm

Caliper holes are 130mm apart so a bracket like this is required.


2 Holes will be 12mm and 2 will be m12 x 1.25 threaded.

rotor hat height is 9mm different ( in theory ) so i need a 10mm plate and 1mm spacer behind disk or 8mm plate and 1mm shims on caliper.

4 x m12 HT bolts also needed. grade 8.8 will do but trying to get some grade 12.9 button cap bolts.

You need some shims also for studs but thats just 12mm id and 15mm od stainless tube so disc is central on hub.

Re: My Budget 300bhp St185

PostPosted: Wed Jun 26, 2013 6:30 am
by MrDB
Next up is the rev2 st185 ecu to st205 rev3 ecu conversion.

the actual conversion requires the following parts

1) 3SGTE Gen 3 ecu 1994-99 Part # 89661-17460
2) Gen 3 Map Sensor Parts # 89420-17050 fit in place of rev2 one.
3) Igniter Part # 89621-26010 fit in place of rev2 one needs the hump on side of connector filing off so plug fits
4) Air Temp. Sensor (THA) Part# 89424-12010 place in / near air filter
5) Manifold Air Temperature Sensor (THAM) Part # 89424-24010 this needs a plate making to fit where cold start injector is.
6) Rev3 injector x4

Pinout diagram in this link

All revs covered rev2 to rev3 has discription on the bottom of the sheet as well as code 54 (charge cooler fix) removal diagram.

Rev2 to rev3 needs very few wires swapping rev1 to rev3 however requires considerably more but take your time.

Note if you have a rev3 mr2 ecu you dont need to do the code 54 circuit fix.

If you need to do code 54 fix you should hear the relay click as soon as the throttle is touched and it then stays active until engine is off. code 54 triggers for low coolant ( LEV pin ) and if no charge cooler motor.

Initial test showed no error codes and fired first time. need to just swap injectors before i can do a proper test drive, will need a bored fuel rail also as it just cant really flow enough for the bigger injectors if you want extra security.

The conversion can be made totally plug and play if your willing to sacrifice the afm connector in the AFM.

Re: My Budget 300bhp St185

PostPosted: Fri Jan 06, 2017 10:51 am
by MrDB
Been a long time since any updates.

Car currently now runs full REV3 ecu.

All working fine and a lot smoother running.

Now has EVo 9 intercooler and clocked turbo.

Engine was rebuilt but had water pump failure ( lost all blades from pump ????) so had to have another rebuild.

Car was off the road for about 2 years due to this but has very recently been put back on road and im enjoying boost again :)

Now running 1.2 bar and fingers crossed it holds together for a while now.

Planning on making a conversion module to run Coil on plug using stock ECU but tha will be summer now.