MR2 Owners Club

Hi, I have a bit of a question If i have any of this wrong please feel free. I am under the impression that when people want to up the power in a rev3 turbo there seems to be a basic setup. Better flow of air in and out, Better intercooler, and turn the boost up to 17psi. I realise the fuel cut comes in at 18psi so is that why 17psi and 280hp-300hp is the limit. It seems a shame as the the rev3 ct20b turbo is capable of 23psi or so they say.
My question is. Is it just the fuel cut that stops us running this basic setup and say 20psi and maybe 290hp-310hp, Is this the point were you move to stand alone ecu's,

fuel cut is around 19psi

people say you can run 1.2bar, which equates to 17.4psi

id say its more of a guide there before any sort of boost spike, or cold weather running could have you hitting fuel cut every boosted run, hence why peeps say lower it to be on the safe side.

there is enough fuel for more than 18psi though.

if you can increase fuel cut, or run a standalone ecu, i dont see why you couldnt run 20psi, how good the turbo is at this level though is another question. some have been known to fail, others not.

19psi fuel cut is there because you're at the end of the ECU's fuel map. It's also in the danger zone for the stock pistons. Yes, you can find ways of going beyond that amount of boost on the stock internals and even the stock ECU. But you're also going to be outside the efficient range of the CT20b and will need some pretty decent intercooling to keep your inlet temperatures in check.

Basically, if you want to go beyond 300bhp you will want an aftermarket ECU (which will get more power from the same boost level). If you want to reliably go beyond about 330bhp then you're looking at ECU, forged internals, upgraded turbo, proper intercooling etc.

I've found that my fuel cut comes in at 18.1psi I've just a couple of accurate meters that hold the reading of the maximum boost pressure reading

jimGTS wrote:
i dont see why you couldnt run 20psi, how good the turbo is at this level though is another question. some have been known to fail, others not.

There would be no way I would run 20psi on stock internals,Ryan an old member on here was running 1.2 bar for nearly 2 years then the piston let go

with the right cooling, no reason why not.
water/meth injection and it can be done.

topgun wrote:

jimGTS wrote:
i dont see why you couldnt run 20psi, how good the turbo is at this level though is another question. some have been known to fail, others not.

There would be no way I would run 20psi on stock internals,Ryan an old member on here was running 1.2 bar for nearly 2 years then the piston let go

Mick's right... each individual engine is different with a different history, and especially at the age they now are what works on one might not work on another. Some people run 1.3bar all day on stock internals and are fine (particularly with WI). Some people have piston rings let go at 1.1bar. It's all down to the individual owner how much risk they're willing to accept.

When I originally got my car I decided I was happy with a lot of risk, so turned the wick up to 1.25bar. That then crept to 1.3bar over a snowy Christmas holiday, the piston rings let go and I ended up replacing the entire engine.

jimGTS wrote:with the right cooling, no reason why not.
water/meth injection and it can be done.

Don't disagree at all... but even if most 3s-gte engines will survive that, some won't. As I said above, it's all about the risk you're happy to take with your engine. I don't think I'd go to 1.3bar again without WI.

jimGTS wrote:with the right cooling, no reason why not.
water/meth injection and it can be done.

Maybe so but the engine will eventually go bang,a big risk to take.Perhaps you should try it on your new car and let us all know how you get on

ha. that is the plan. but first i need to take care on cooling. not sure which direction to head yet.

So you need forged pistons to be safe. What compression would you use. If your running a bit more boost than standard should you use a lower compression piston.

blogsy wrote:So you need forged pistons to be safe. What compression would you use. If your running a bit more boost than standard should you use a lower compression piston.

With the right map; compression doesn't matter.

I've known the pistons fail on stock boost.
As shinny states all different one to the next

MRturboTom wrote:I've known the pistons fail on stock boost.
As shinny states all different one to the next

Amen to that.

My Ringlands were shot and the car had been running stock boost only.

Dont mean to hi-jack but does a Rev 2 tubby run about 10psi as standard? and if i wanted to up that to say 13psi how is it best done?
I used to own Renault 5 Turbo's but they were so easy to 'play' with as they had a carb so if you sorted the fuelling our you could wind the actuator to increase the boost pressure, dont see these been as simples mind you?!?