GTB1756 limit?

[hutchysrs50]

That's pretty much what it's running now, yeah. I wanted it closer to 240bhp though.

[badger89]

That's pretty much what it's running now, yeah. I wanted it closer to 240bhp though.

 

Just jump onto D E R V T E C H ' S Dyno you'll probably make over 240bhp without touching a thing...

Edited 4 October, 2016 by badger89

[Jrjg]

I ran under 2.1bar and made 230bhp and 410ft/lbs

410ft.lbs - that seems very high!

JRJG

[badger89]

410ft.lbs - that seems very high!

JRJG

It boost well low down with minimal lag, that torque was achieved at 2200rpm

Mapped by Faboka

[Jrjg]

It boost well low down with minimal lag, that torque was achieved at 2200rpm

Mapped by Faboka

Was this a 1756 on standard injectors?

[badger89]

Yes, just a GTB1756VK, FMIC and Straight through exhaust.

[coskev]

Torque readouts vary massively from one RR to another,different gears used etc all alter the torque reading.

[Jrjg]

Well I hope mine isn't anywhere near that figure. Otherwise it will soon be time to say goodbye to the updated clutch.

[badger89]

The standard (new clutch) lasted about 10,000 miles before I had to install a SMF.

It was done two years ago and the torque reading is roughly right compared to the other cars tested on the day. I think it was slightly over so probably around 380ft/lbs to be realistic.

[ajs_vrs]

Ha at derv tech, pushing cars and making them into the ticking time bombs.

I wouldn't go more than 2.1bar on stock pistons with stock injectors, it's not just one or two cars that have failed.

Even with dssr or firads it's pushing it, although more reliable.

Kris is the best tuner guy to talk to.

Edited 11 October, 2016 by ajs_vrs

[Jrjg]

Ha at derv tech, pushing cars and making them into the ticking time bombs.

I wouldn't go more than 2.1bar on stock pistons with stock injectors, it's not just one or two cars that have failed.

Even with dssr or firads it's pushing it, although more reliable.

Kris is the best tuner guy to talk to.

I follow them on Instagram to see the drivvle they broadcast. Some days I sit there with a disgusted, open mouthed look on my face; "remapped Fabia vRS, bit of smoke on this one" is the caption to a video showing a Fab pulling away on a motorway from whatever speed to whatever speed, the black plumes its leaving behind it is shocking. I would hate to see what 'a lot of smoke on this one' looks like. Probably smokescreen all three lanes.

JRJG

Edited 11 October, 2016 by Jrjg

[ajs_vrs]

I don't think it's a case they don't know what they are doing to be fair to them it's just pushing cars to limit and turning into ticking timebomb with bigger turbos on, because it's a diesel you get away with it to an extent, pushing cars with no research. You only have to look on here and tdi club that's its not just one or two breaking.

[Harry1212]

Diesel tuning is still at it's early stages, after going down the hybrid route myself i've discovered that if you want reliability then you should just stick to a simple stage 1 map from standard to 170/180bhp

[Jrjg]

Diesel tuning is still at it's early stages, after going down the hybrid route myself i've discovered that if you want reliability then you should just stick to a simple stage 1 map from standard to 170/180bhp

Diesel tuning has been going on for a long time, 15+ years or so. Wouldn't quite say early stages. Not for the PD engine tuning anyway.

JRJG

[EKM]

At risk of going off topic, I stay away from debates about pushing stock injectors to their limits (I know what my limits are and i'm sticking to them), but one area which might be worth some thought for any interested parties that I don't see get discussed often, is not so much the egt itself but how the combination of high egt and long durations work to increase the risk of component failure.

 

If you touch an oven quickly, you will most likely not suffer as much pain as if you lean a finger on it over a few seconds - it might be worth considering how well this analogy translates the internal condition of the PD engines, does injecting an excessively long stream of fuel over an operating band where combustion is likely to be at a low level of efficiency going to allow components more exposure to the heat and thus higher temps, even if the egt remains constant compared with an engine with bigger nozzles?

 

I'm not a metallurgist but it's always worth reading between the lines and trying to come up with some ideas. Obviously tuning is an oversubscribed industry and I think the duration thing has been a bit of an easy target, most tuners don't push it so if you can make some unusually and unique high power figures running long injection duration and not buying nozzles it is, in the short term at least a way to win PR and make an economic case for this mode of tuning as well.

 

I don't think many tuners who work with big nozzles will rush to compete or defend this though, they limit themselves for their own reasons and I think they'll have faith in their numbers, duration guidelines etc and any desire to come out with high horsepower figures won't liekly be able to over-ride this. It's having a known safety margin, an established gap between the max an engine can put out, and what it is programmed to put out, that gives that 'you can boot it anytime, anywhere' guarantee.

 

One thing of note, and this effects everyone at every level of diesel tuning - failure can be as slow or as fast as it likes, you can blow something up in minutes but sometimes it can take material a long time, hundreds or even thousands of drive cycles before a fault develops to a level where a catastrophic failure is inevitable -  its not unreasonable to suggest that its possible to stress a component during tuning in way where a failure can happen months after the fact - building a high power engine is one thing and thats difficult but proving it is another. It does make sense from a traditional engineering point of view to take on as little risk as possible, though invariably there is always some. It;s very difficult/impossible to accurately model the effects tuning decisions will have on an engine from an aftermarket perspective, thankfully we have rules of thumb - which might seem a flimsy approach to risk control however these are built on experience and that's worth a million lab tests.  

 

That's just my feelings on the injector front anyway, regarding the max power of the GTB1756, I'm fairly conservative, I don't personally think they're cop for much post 230-230, but if you don't mind a little less you can run them quite clean. You wouldn't have to absolutely drive this turbo from an energy/shaft torque point of view so a small sacrifice in power can actually yield decent benefits in reduced smoke, which is something that can get a bit trickier with larger blowers. As things stand, the GTB1756 (none hybrid) is my personal preference for medium budget projects. There probably are better blowers out there but these do a good job.

 

The above rambling is all my 2p worth and nothing more.

 

Kris

Edited 12 October, 2016 by EKM