safe levels of boost

[Jonny4494]

i have a rev 2 turbo with an uprated intercooler(unknown brand) japspeed exhaust, mushroom filter. running standard internals i think!

im going to be buying a greddy profec OLED boost controller.

what would be a safe target boost for both boost lo and boost hi settings?

i dont want to run too much boost and risk my engine going pop.

also need somebody to give me some info on setting the gain and set percentages.

cheers,
jonny

[Odin_S]

Well anything more than 1bar of boost is considered too much for standard rev 1/2 internals

[markstevieandmads]

I tried to set my rev 2 up for 0.9bar but the standard ct26 just won't hold it up the rev range so it peaks at 0.9 but settles at 0.8. Plenty for me.

[Jonny4494]

not sure wether or not my ct26 is a hybrid or not. when i bought it the owner said it had an upgraded turbo. but without a closer inspection i cant tell.

[e4jon]

im no expert but im sure you hit fuel cut at around 12 psi (0.8 bar) on a rev2, unless you fit a fuel cut defender

[alanmr2turbo]

Well anything more than 1bar of boost is considered too much for standard rev 1/2 internals

LOL no not the internals its the headgasket thats meant to be the let down.

I have heard of people running 1.2bar on standard re1/2 headgasket for yrs without a problem. Just the luck of the draw.

[Jonny4494]

So the internals are quite strong then? What about a cometic head gasket? Would would that increase reliability? If so, what size would be the best to get? Also, if I were to buy a fcd what sort of boost levels would be the maximum?

[gnzyza]

Not sure of safe levels but the rev2 head gasket is the weak point.
also recommend a compression test before raising

[Draven]

A cometic headgasket would work. I'm not sure on which one. I believe a simple upgrade of a Rev3 metal headgasket is also a good way to go..

The headgasket is defo a failure point of the rev2 engines.

I wouldn't put more that 0.8 bar of boost through a CT26 on a rev2 if i'm honest.. and no more than 1.2 bar of boost through a CT20b on a rev3. Even then I would be very careful of knock, oil pressure, temps. Make sure you've got at least an aftermarket Intercooler. That should be the first upgrade when upping boost..

These engines are getting on now. So they need to be treated well.

[Jonny4494]

I'll get a cometic or a rev3 one then, already got an upgrade SMIC
Just need to know what thickness to get for the head gasket if I'm going to get a cometic

[alanmr2turbo]

you can use a standard rev3 headgasket and with fuel cut 1bar after that you really need to do rev3 injectors, ecu etc then you could raise boost to 1.2bar and then you'll be able to loose the FCD

[Draven]

you can use a standard rev3 headgasket and with fuel cut 1bar after that you really need to do rev3 injectors, ecu etc then you could raise boost to 1.2bar and then you'll be able to loose the FCD

I still wouldn't boost 1.2 on a CT26.. it runs out of puff

[Mr Bognor]

CT26 hybrid would be ok tho

you can use a standard rev3 headgasket and with fuel cut 1bar after that you really need to do rev3 injectors, ecu etc then you could raise boost to 1.2bar and then you'll be able to loose the FCD

I still wouldn't boost 1.2 on a CT26.. it runs out of puff

[Draven]

CT26 hybrid would be ok tho

you can use a standard rev3 headgasket and with fuel cut 1bar after that you really need to do rev3 injectors, ecu etc then you could raise boost to 1.2bar and then you'll be able to loose the FCD

I still wouldn't boost 1.2 on a CT26.. it runs out of puff

Yes a hybrid should be fine.

[bobhatton]

A cometic headgasket would work. I'm not sure on which one. I believe a simple upgrade of a Rev3 metal headgasket is also a good way to go..

The headgasket is defo a failure point of the rev2 engines.

I wouldn't put more that 0.8 bar of boost through a CT26 on a rev2 if i'm honest.. and no more than 1.2 bar of boost through a CT20b on a rev3. Even then I would be very careful of knock, oil pressure, temps. Make sure you've got at least an aftermarket Intercooler. That should be the first upgrade when upping boost..

These engines are getting on now. So they need to be treated well.

Nothing wrong at all with the stock Rev1 and 2 head gasket I have raced for 3 years at 1.5 bar boost with a stock Rev2 engine............but was on high octane fuel.

The problem is knock, every turbo MR2 with a stock engine is running under the control of the knock senser, our fuel is just not good enough to run stock boost, so if the boost is turned up someting has to give, and it is the head gasket.
Fit a better gasket will stop that going but the next thing to go is the big end bearings and or pistons.

[Draven]

A cometic headgasket would work. I'm not sure on which one. I believe a simple upgrade of a Rev3 metal headgasket is also a good way to go..

The headgasket is defo a failure point of the rev2 engines.

I wouldn't put more that 0.8 bar of boost through a CT26 on a rev2 if i'm honest.. and no more than 1.2 bar of boost through a CT20b on a rev3. Even then I would be very careful of knock, oil pressure, temps. Make sure you've got at least an aftermarket Intercooler. That should be the first upgrade when upping boost..

These engines are getting on now. So they need to be treated well.

Nothing wrong at all with the stock Rev1 and 2 head gasket I have raced for 3 years at 1.5 bar boost with a stock Rev2 engine............but was on high octane fuel.

The problem is knock, every turbo MR2 with a stock engine is running under the control of the knock senser, our fuel is just not good enough to run stock boost, so if the boost is turned up someting has to give, and it is the head gasket.
Fit a better gasket will stop that going but the next thing to go is the big end bearings and or pistons.

So you're saying that Tesco 99 ron fuel isn't good enough? I didn't think you could get much higher other than propper race fuel.

[Jonny4494]

So would you recommend using tesco's momentum 99 in them? Would it prolong the life of the engine?

[bobhatton]

A cometic headgasket would work. I'm not sure on which one. I believe a simple upgrade of a Rev3 metal headgasket is also a good way to go..

The headgasket is defo a failure point of the rev2 engines.

I wouldn't put more that 0.8 bar of boost through a CT26 on a rev2 if i'm honest.. and no more than 1.2 bar of boost through a CT20b on a rev3. Even then I would be very careful of knock, oil pressure, temps. Make sure you've got at least an aftermarket Intercooler. That should be the first upgrade when upping boost..

These engines are getting on now. So they need to be treated well.

Nothing wrong at all with the stock Rev1 and 2 head gasket I have raced for 3 years at 1.5 bar boost with a stock Rev2 engine............but was on high octane fuel.

The problem is knock, every turbo MR2 with a stock engine is running under the control of the knock senser, our fuel is just not good enough to run stock boost, so if the boost is turned up someting has to give, and it is the head gasket.
Fit a better gasket will stop that going but the next thing to go is the big end bearings and or pistons.

So you're saying that Tesco 99 ron fuel isn't good enough? I didn't think you could get much higher other than propper race fuel.

That is right 99 ron is not high enough even for stock boost

[Jonny4494]

What fuel has the right octane rating then? Race fuel wise

[bobhatton]

What fuel has the right octane rating then? Race fuel wise

That all depends on compression ratio and boost pressure used.
With a stock engine and stock boost 102 will be ok