Increase BHP engine build. What's needed?
Turbo Mini Forums

I am about to start building a turbo engine for my ERA. A couple of years ago I acquired an unused Avonbar bottom end with omega 18cc dished pistons. I don’t think I can use these pistons as I believe I would have to run an intercooler.
What BHP is achievable without intercooler?
I don’t have the space for one as the ERA has a auxiliary radiator on the drivers side front and I also would like to keep it looking as close to original as I can. I have an unused standard spec engine that has been re-bored and reworked
What I would like to do is to increase the power above the standard turbo engine to a level just below the intercooler level if that is possible. Driveability and Reliability being important. I would want to use the Garrett type 3 turbo unit as this was standard on the ERA
I know this is like asking how long is a piece of string but any information would be appreciated.
So any suggestions as to parts
Piston type
Head and valve type
Camshaft
Dizzy
Carb and needle
Turbo modification
And any other details like.

The restoration of this vehicle has taken too many beer tokens so far so I need to keep the cost as sensible as possible.

Get rid of the auxilary radiator and run an intercooler there.

you wont have to run an intercooler just because you have those pistons.

one day boost will be mine!

IMO the first mod on any turbo motor should be adding an intercooler if there isnt one as std... its a case of anything is better than nothing!

plug some figures into this and you'll see how hot the inlet charge can get with out a cooler. somtning like the S2 escort RS turbo ones are cheap, fairly small and effective.

http://www.motorgeek.com/?fullpage=true&page=flowcalc

either engine is a good starting point, get an inter cooler on there, bleed the boost to 10psi and get it set up on a rolling road. oh and put in a cross pin diff.

Edited by Joe C on 6th May, 2012.

OK.
Bearing in mind that I would like to keep it as original as possible ie. auxiliary rad in place. Does that mean there is no increase in power to be had reliably without an inter-cooler?
The auxiliary rad is only a bolt on extra and can be removed or reinstated at any engine change so I am not entirely against removing it.
As I already have the +20 18cc dished omega pistons and the Avonbar bottom end, that would be the most cost effective at the moment.
I am not building a race car. A drivable and reliable engine is important. The car ERA would have liked to have built.

What head spec then, with those pistons?
The cam I have in the bottom end I believe is a phase 2 whatever that will give me

If you insist on not using an intercooler, then you need to have a low compresiion ratio to avoid detonation.

The Avonbar short engine with 18cc dished pistons would be ideal for this.

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."

Does the ERA run the same boost modilation as the Metro turbo? If so, bin that for a start and fit a bleed valve.

With the 18cc postons, aim for 8.5:1 CR and up the boost to 8 to 10 psi. That will be a noticable increase in power.

The other thing to do is fit a different cam. There is lots of choice, have a search.

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

I can understand you wanting to keep it looking original on an ERA.

If you use the engine you have with the 18cc pistons and ph 2 cam you will be able to make decent power very comfortably, the only trade off will be that you will need to keep the compression ratio low to avoid detonation with no intercooler and higher boost, this in turn will make the engine less responsive off boost. As Wil says above aim around 8.5:1, do not be tempted to go too low.

The reason for trying to keep it ERA original is its rarity.
I think I am being persuaded to go for the intercooler.

So to recap
18cc dished pistons are good
Phase 2 cam. Not sure
Keep compression ratio 8.5: 1 (a head from turbo minis or other machined to give me that)
Using a boost of about 10 psi

What about the distributor?

could you fit megajolt? as its much better than a dizzy!

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

Anything is possible, but personally on an ERA I would keep any mods internal to the engine and keep it totoally standard to look at.

So can anything be done with the standard engine/pistons and no intercooler to safely increase the power?

standard pistons can be dished out a little to lower the CR. That said, standard turbo pistons with 28cc in the head give around 8.3:1

I would use the avonbar bottom end, give the gearbox an overhaul, fit a x pin diff. Just work out your compression ratio, changing the head cc's accordingly, until you reach your desired ratio, (8.5:1). Set up well with no intercooler, I would say 12psi is achieveable, which is 3x standard boost, should make a nice motor.

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

1.7 times standard boost?

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

If they run 7psi like the metro then yes.

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

They are just a metro turbo engine, in a mini.

one day boost will be mine!

Yes but wasn't sure if they used the metro turbo ecu.

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

If something is worth doing, it's worth doing half of.

So do they stick at 4psi longer before bleeding off to 7 or do you mean they use a lesser actuator than 4psi to start with?

one day boost will be mine!

http://www.eraturbo.co.uk/roadtests/anewera.htm

There is a section about where peak torque is produced.

I saw a graph once comparing the boost vs. rpm on an ERA and a metro turbo but can't find it now.

If something is worth doing, it's worth doing half of.

the only thing i can find which hints at a difference is this:
'Such an arrangement made fitting the Garrett AiResearch T3 turbo unit a bit tricky. But fit it does, delivering a non-intercooled 8psi of boost at 6000 rpm blowing through an HIF 44 SU carburetor. The ERA Turbo develops 94 bhp, one horsepower more than the Metro Turbo. Torque is up to 87 lbs.ft at 3600 rpm from 85 lbs.ft at 2650 rpm. The Mini Turbo can live with the torque peak at much higher revs for one very good reason. At 1624 pounds, it weighs 251 pounds less than the Metro.'

also this was an interesting read, http://www.eraturbo.co.uk/history/erametrover.htm
top right of the screen is an arrow to turn the page. took me a while to notice it, lol

showing ERA tried a mod ive seen on here of direct lube to the drop gears.

one day boost will be mine!

Ok
I use the Avonbar parts I have.
Source a new head
Gearbox overhaul with X pin diff
No intercooler (keeps it looking like an ERA)
No ECU
Fit a bleed valve
10 to 12 psi boost.

This is looking good

Is the standard Garrett T3 turbo OK?
Would it need a dump valve?
Do I keep the Metro electronic dizzy?

Standard T3 and dizzy ignition is up to the job. But you would need a good RR setup.

I think you may need to block off the standard overboost/pop-off valve in the plenum as I think these start to leak at about 10psi. A DV would be beneficial too but not 100% necessary.

Edited by John on 8th May, 2012.

If something is worth doing, it's worth doing half of.

how about fitting a subtle water injection setup to try and combat the det if you read the aquamist forums it seems to be very effective.

Speeding is like masturbating, everyone does it, but not all of us film it and put it on the internet

[quote=fab,8th Oct, 2010]fuck off