Budget turbo tips

[nedski]

I'll split this into sections as I lost a big post on my first try
I'm not a turbo guru I just own and use a budget turbo setup on road and track days. So I'll waffle on with my experiences and add tips and pointers along the way. Don't forget these are my opinions and nothing is gospel and some things could be plain wrong lol.

For starters do your homework and then do some more, and a bit more. The more knowledge you have the less chance there is of making a c*ck up and wasting precious hard earned cash.
Get a "want to buy" list together that can be built on and up . ie if you buy a wide band o2 sensor then get one that will match an ecu you may want at a later date. no point buying something incompatable. boring and obvious yes and obviously I didn't practice what i'm preaching

I'm calling this budget tips because I don't have a Megasquirt or similar.
So my car spec-
Cast manifold and Garret T3 turbo (on car when bought )
Jackson racing afm black box (on car when bought )
Jackson racing adjustable ignition retard (on car when bought)
The car was running with just the above at 5-6 psi

I've added-
Bailey dump valve
mondeo diesel intercooler
adjustable rising rate fuel presure reg, later changed for a 12:1 arrfpr
manual boost controller
mx5 mk2.5 red injectors (a bit bigger )
o2 clamp and boost pressure switch 0.5 psi
5th injector and boost pressure switch at 4psi
alloy radiator
1.8 flywheel lightened and new standard 1.8 clutch
turbo timer with shift light
wide band o2 sensor with gauge A MUST HAVE for engine safety
This lot gets me up to a very safe 11psi and 15psi tops.



Remember don't just slap you turbo on get excited and thrash it down the road
cough splutter cough and Bang will follow.

Your turbo pushes loads more air into your engine than your stock ecu and ancillaries can handle and fuel. So if your stuck with your standard ecu you need to trick it into fueling more, and squeezing more fuel past your injectors. Without an ecu they are called band aids. This is all in aid of keeping your air fuel ratio's (AFR's) at a good safe working level. Things do melt very quickly or simply detonate to destruction.
This is why I think a O2 sensor and gauge is a must. Otherwise you running blind....

I guess this is enough background I'll run through my bits and pieces and why's and how's next.
Hopefully some of it will help somebody

[Mazda Mender]

So I'll waffle on with my experiences

And that is what it is all about
M-m

[flea]

Nice write up.

[Lazza]

All good & useful information. When I get a chance I'll do a write-up of what I've had fitted to my car over the last 9 years.

[Mazda Mender]

All good & useful information. When I get a chance I'll do a write-up of what I've had fitted to my car over the last 9 years.

M-m

[nedski]

Ok ups and downs of my Garret t3. It is getting to be an older model compared to some modern stuff so does spool up a bit slow and higher up the rev range, but saying that on track its fine appart from Mallory hairpin up to now.
pic 1st


oops double post

[nedski]

Ok my Garret t3 experiences. It's an older model by todays standards and spool time is a little slow and high up the rev range. Thats been fine for the track up to now appart from tight hairpins where revs drop off.

pics first


When I bought the car the turbo was fitted already. No intercooler or dump valve but it felt good and the cars body has no rot, so I bought it.

First mistake/fault.
The oil return from the Turbo can either drop down and be tapped into the sump or travel around to behind the alternator and enter the block there. Mine travels around and while tidying up the engine bay I moved the return pipe from the being cable tied to the fans to running along cross member under the sump.
Mistake- The return should gradually fall all the way around back into the engine. With dropping mine down to the cross member and back up again the oil collected in the bottom of the pipe. This builds up a back pressure in the pipe instead of simply flowing away. 2 weeks later the Turbo sprung an oil leak
So its now cable tied to the fans again. The service to the Turbo cost £350 .
pic of return pipe attached to fans.


Next Problem- Heat. The water pipes around the back of the head into the bulk head and heater were already old and gave way to the extra heat. pop.. They are now new and wrappped in heat wrap.


Next problem- Manifold studs. Pain in the ar*e so far and still causing grief. Firstly they turned out and I lost 2 studs. Or they just come loose and blow gaskets. Ive tried different stud locks and nuts but I'm resisting the Inconel Studs from America that are supposed to be the cure. They are expensive and there is inport tax and delivery.
Blown gasket from loose studs photo

When it blows again I'll try without a gasket. The manifold is cast and so far has been fine.
Hope some of this helps.

[Mazda Mender]

It all helps
M-m

[nedski]

Blow off valve/ Dump valve.
Mines a bailey.

Problem- It leaked pressure on slight cruising throttle. It made it hard to run slight throttle as it would pull and back off repeatedly.
The bailey works and opens only when there is a vacuum in the inlet side of the throttle body and boost from the turbo side. Unfortunately on slight throttle the inlet has a vacuum while the turbo can still boost. So the bailey opens.
Cure- upgrade the spring inside to open at larger vacuum and boost.
I added a second helper spring from an RC car suspension. These come in many sizes to help choose the perfect one.
Spring from this inside my Bailey

[nedski]

Intercooler.
Problem- The car didn't have one.
This caused high inlet temps and the ignition retard had to be backed well off to stop detonation.
How did i know? Don't laugh but not knowing what the car was doing I made these in the first week of owning the car. Home made Detonation detectors.
Take 6 inches of copper tube and flatten on end, then drill a 10mm hole to get a bolt through. Then undo a engine mount bolt that bolts into the block drivers side. Then bolt on your copper tube in place with that bolt. The copper tube amplifies detonation knock (pinking) so you can hear if your destroying your engine.


Cheep but effective. I now have electronic ones but they pic up so much interference I go back to the simple pipe method. You can also see the blue pipe in that pic direct from Turbo to throttle body with no intercooler.

So budget Intercooler - Ford Mondeo diesel 2003 intercooler. I choose this because i had one laying around!
The silicone pipes I had to pay for. Anyway it fits and works
This is a pic from underneath with my radiator removed.

Believe it or not I added around 6 degrees of advance to my timing with the intercooler fitted. Although it brought on a secondary problem of weakening my afr's withthe denser Air.

[nedski]

Timing
If you are going the retro budget route ( seriously think hard a plug and play ecu is far better) like me as my car already had a budget one fitted when I bought it. You still need to tune the car the best you can.
As far as ignition timing goes i'm lucky the last owner fitted a jackson racing boost ignition retard little black box.
With this I can run 16deg advance off boost and the ignition will retard as I go into boost. This can be varied by a control knob. I can then tune to safely give me max advance without detonation.


If You don't have anything to control your ignition you will have to knock back your timing advance to maybe 6 deg. This is as good reason to go PNP as any. Without timing control you will have a very flat feeling engine off boost. And if you have too much advance detonation can soon do lots of damage on boost.

[nedski]

Engine safety , Wide band O2, Knock Sensor.

Once again even if its a budget setup you don't want a blown engine.

A wide band O2 with gauge is a Must along with some sort of Knock (pinking, detonation) detection.

Do your homework !!
Basics are Don't let your AFR's rise above 12.5 on boost and use knock detectors to make sure you don't have detonation either. That will at least get you started.

Use something like this.


My experience .
Everything Ive changed or added altered the Afr's. The wide band is all i have to tune the fuel ratio's .
Without it your running blind .
It also helped discover what was happening in a flat spot going into boost and is the reason i have fitted an O2 clamp.

It's all fairly basic stuff but without a proper Pnp Ecu you can only do a simple tune, but you can still keep your engine safe and thats the most important thing.

Knock sensors with headphones.
There are quite a few post's on the subject.
I had a go at 2 different designs.
One was simply with a pipe attached to the block .
The next used a guitar amplifier connected to a knock sensor bolted to the block.
http://www.mx5oc.co.uk/forum/forums/p/50491/369120.aspx#369120
Simple stuff hope it helps someone starting out.

I preferred the pipe to be honest. Simple yes but knock is loud and clear with little interference.

[nedski]

I'm still waffling on.
Things I've fitted to raise my boost

The intercooler Ive already mentioned.
Manual boost controller (ball and spring type)
5th injector on a boost switch just to get enough fuel in.
adjustable rising rate fuel pressure reg 12:1 ratio

5th injector is fitted in the inlet pipe below the throttle body. The mk1's fire the injectors in a batch ( i think anyway) so iv'e taken power off the front injector in parrallel. This is switched on when boost raises above 4psi.


All in all with all these fitted it can reach around 13psi safely.
and this is a close up of brass boost controler, arrfpr, boost switches for O2 clamp and 5th injector. quite a few pipes around

[Lazza]

The mk1's fire the injectors in a batch ( i think anyway)...

Correct, and Mk2/2.5 is no different, they all run batch injection. With my Adaptronic I can make it run independent sequential injection but that would require rewiring the injectors and I just can't be ar5ed with that. All I'd gain is a slightly better economy. The big advantage of batch injection is that the spray of fuel on the back of the closed valve helps to keep things cool.
The ecu also runs a "wasted spark" system where 2 plugs are fired together (1 & 4 and 2 & 3). That does no harm at all other than doubling the work the coils have to do and in theory limiting the rev limit as the coils have less time to recharge. It also means that you can swap plug leads 1 & 4 and 2 & 3 and the car will still run exactly the same.

[nedski]

Nearly done.

Flat Spot

I had quite a flat spot entering boost and the afr's went lean. Doing homework i read about the O2 clamp.
what does it do? - It simply sends a signal to the ecu to fool it into thinking the mixture is lean.
How? The ecu gets a signal from the Lambda sensor that varies between 0-1volt this has a half way switch point at 0.5 volts. If it sends a signal 0.5 -1 volt the engine is running rich, from 0-0.5 volts the engine is running lean. With this information the ecu along with the air flow meter trims the fuel. So the O2 clamp cuts into this signal immediately there is boost and mine provides a voltage of 0.35 volts. The ecu thinks the engine is lean and tries to provide more fuel.
Fitting this helped eliminate the flat spot.

Tips. O2 clamp circuit
http://www.miataturbo.net/diy-turbo-discussion-14/o2-clamp-pressure-switch-16397/

just walk into maplins and they will supply your parts.

boost pressure switch from here. hard things to find...
http://www.methanol-injection.co.uk/product_info.php?cPath=27&products_id=83

my O2 clamp home made. really simple

hope this lot helps someone in the basics
If i've got something wrong I'm sure someone will point it out.