Yes standard internals, it is well mapped and has water injection too

OK that's good to hear, so an RS 0.64 should be somewhere in between your GT28R and RS 0.86.

Seems to be quite a split of opinion as to what spec gives a reliable ball park 350bhp. Still not convinced that all the extra expense (circa £3-£4k) is worth the extra 50-70bhp.

Jules.

Your not far away from me, you can have a drive in mine if you want.

Cheers Matt, I might take you up on that.

Jules.

Yes that is correct modified correctly in my experience means forged internals.

Mine did not go pop as I didn’t run std internals but I know many that has, most on here can comment. It has been discussed very much try a search and the conclusion is that the 320bhp mark is an estimated limit. Over time the ringlands will go, some are luckier than others. I cannot put a time stamp as to when but with less low mileage coupes about wanting to put 350bhp into this will only speed up fatigue no matter how well mapped. More power is more heat; heat is dissipated to the cylinder walls via the rings. This extra heat and more time exposed to it takes its tolls on the ringlands.

Fair comment.

So 320bhp-350bhp is a grey area then?

Jules.

IMO with std internals, yes

I partly agree - I ran at about 330bhp and 340 lb-ft for a while with forged pistons on standard rods.

I have a feeling that I *might* have turned up the boost for a few moments and the end result was a bent rod

So - I'm not sure there is such a thing as "safe & reliable 350bhp on standard internals" - personally, I reckon its a grenade with the pin already out. Sure, if the car is doing low mileage, it might last several years, but for me, I need an engine that will do 100,000 between rebuilds.

Jules - this is why several people are suggesting going for Luke's car (or Eldinho's - pretty sure he'd part with it for the right cash) - both cars will give 350bhp all day long, because the engine was built (and mapped) with safety in mind and huge tolerances to handle the power.

I'm fairly sure that mine could now handle 2 bar with ease - with a bigger turbo, it would probably give around 450bhp. The gearbox would be a pile of swarf and chewed teeth and the clutch would be toast, but the engine would be fine.

decisions, decisions....

As you may know my ringlands cracked running 350-360bhp. Originally I thought this was down to the pistons not being up to the job, as the previous owner had the car RR'd many times to check the fuelling. I also had it checked myself 2 days before she went pop and the fuelling was fine.

Since then I have discovered that the methanol/water injection jet was way too big. I think this was done to bring the AFR down without the need of bigger injectors. This really isn't the best solution as the methanol isn't injected into each cylinder but into the intake. Leighton found when mapping the car with this jet the fuelling was seriously effected, this is why the methanol isn't currently being used on my car.

This is a VERY good point. There is a very big difference between an occasional blat to the redline in 3rd gear, and regular pulls to the redline in 4th. I'm sure there are lots of tuned coupes out there that run plug and play chips that are fine on the road, but take them to a track and things would be different.

I'm pretty sure that Luke's car is not running forged internals?

That's interesting - I know that your previous engine was pushed hard on occasion, and boost was pretty high as well. I think it managed 50,000 miles when tuned, which I think is acceptable for a very tweaked 2lr engine - but then I guess it just depends on how many miles you are going to do in the car.

Another reason not to run Aquamist then......(hopes this thread does not go off on a tangent.)

You are correct Si, the engine did get pushed very hard. And thats the way it should be, the performance of these cars can't be used properly on the road. I'm not complaining at all that the engine went pop as I still had a car with thousands spent on it. I'm not sure that too many miles were actually spent on the RS though.

I still think Aquamist is a good modification, but shouldn't be used to fuel the car. Bigger injectors is the way to go!

Guys,

All good comments, keep them coming, not too worried if it deviates slightly away from the original question.

Jules.

You're right - my mistake - Luke is running bolt-on goodies only (lots of them mind )

Just to add that my engine went pop after running 350bhp on standard internals and a GT28RS. It was great fun, really responsive and very little lag and then the middle piston melted....

Anything over 325bhp and 320ftlbs of torque and you are living on borrowed time.

What spec are you running now?

What boost were you running when your piston melted?

Out of interest Richard how were you fuelling the 350bhp?

Mark, I was on the limit of the standard injectors with a 3 bar FPR. The car was live mapped at perfect touch.

I was also using the water / methanol injection. My spec at the time was almost identical to Joe's but my car was marginaly quicker than Joes with a slightly better spoolup.

After the piston melted, I went for a full rebuild with forged internals. My current spec is currently almost identical to TorboJ's as our engines were built side by side by TrickyMex.

The only real difference between my spec and TuurboJ's is that I have more head work and a GT2871 wit the .86 housing. Currently at 420bhp and 416ft/lbs of Torque!

Hi Jules,

I have driven since 55 200 km (some 34 000 miles) with GT turbos, first was GT28RS (0.86) and now I have GT3071R (0.86). With std internals I drove some 70 000 miles and always above 350 bhp (torque +350 lb-ft, last 1.5 year +400 bhp).
Now last August I changed internals, but the OE ones are in excellent shape. Like there has been OE turbo with OE setup.

So, in my point of view the "safe or reliable setup" consist from many different points, which all has something to do with the engine last/failure.

Did you ever managed to test Jamies Coupe, he did have the GT28RS (0.64) and was well above the 300 bhp mark?

If you only seek for the bhp value, the 350 bhp can be reached with some 1.35 - 1.4 bar boost. With that boost the torque stays in decent level and the engine will more likely stand without any prolems.

One example (the other way around) is my friend, he did melt his piston with only 319 bhp. Okay the turbo was GT28R, so it was quite in the limit.

Other friend of mine did have 445 bhp (GT3071R) with OE internals and never had any problems. Now he has forged internals too.


-Jari-

do you know what jet size you were using?

Good write up Jari (I was wondering weh nyou were going to post - are you well?)

I think your post is very well balanced and your point centres around how well set up the car is both mechanically but importantly from a mapping capability perspective. This is why I think that 350bhp (ball park) can be reliably reach without fear of catastrophic failure. I am sure that great progress has been made in the 3/4 or so years since people have been regularly upgrading to the various now well known turbos and this includes both technical/mechanical upgrades, how they are fitted and how well they are then mapped.

I have a sneaky feeling that a lot of the engines with melted pistons might be that way as a result of too muchy boost being dialed in over an above what the engine was capable of handling, coupled with in-efficient mapping then it's a recipee for disaster.

I can remember Jamie's car very well but am not sure what power it ran (maybe 340bhp?), can you remember Dan20VT's car? This ran a GT28RS with 0.86 at about 330-340bhp but was always for some reason quicker than Coupes with bigger turbos and apparently more power, I am sure he did a 13.0 second 1/4 mile and this was with a slipping clutch and road tyres! A fast car on the road and I am sure his engine never went pop.

Some great comments on this thread and some very interesting reading of Owners experience. I can fully understand why an owner would want to go to uprated internals and then with it a bigger turbo and more power, however, from a cost perspective it would push a Coupe away from being an Ownership prospect for me.

Jules.

That's impressive.....must be a monster on the road?

It is certainly a handfull, especially with the crappy pads I have on it at the moment

lets say i went for the full forged route what would be a safe power level? i would really like atleast 60k out of the engine and ideally over 400bhp to make the forge route worth while

If you rebuild the engine with forged internals, providing the engine is put together well and all the barings pumps etc are replaced, you should be OK all the way to 500+bhp.

But it won't be cheap as TuboJ said.

Its just gearboxes you have to start worrying about!

Im runing standard Internals yes but my torque is only 301lbs, Torque is what ends up killing standard internals so at 300lbs im in Good tolerence, if i opened up the exhaust to Full 3" then maybe it wouldnt help engine life as would give me more torque & top end power but i havent and atm at 1.4bar it is more than quick enough. It only makes 350bhp at the top end so if your gonna live on the Redline every day then yeah its gonna be push & shove but if your just driving in blats here and there, track days here and there its fine. My car is fueling perfectly and engine is still as healthy as ever.


with torque being lower than it could be id say if looked after it will be fine for many miles to come.

Which is why I've stopped (that and the fact I use it in heavy traffic, which means a paddle clutch isn't really a viable options, which in turn limits me to a Helix organic, which in turn, limits me to about 400bhp / 350 lb-ft)

However, I still killed the synchro on 4th gear which required a gearbox strip & rebuild - thankfully, Trevor had a full set of internals lying around from his race car, so I did it on the cheap.