Hi as the title suggests what is the limit of a gtb1756 in power and torque. The car I've bought has one fitted and the clutch is slipping so I'm toying with upgrading the clutch and then remapping further.

What boost is it running now?

The chart on Darkside website says 230bhp @ 31psi.

 

Mine was initially mapped and went on the rollers and did 240 bhp and 350lbs torque, it was over boosting and smoked a lot though, I think 210-220 bhp is more realistic on a low smoke map @ 2 bar.

Not a clue mate. Guy I bought it from couldn't remember exactly what it made or what boost it was running.

If there is enough headroom in the turbo to warrant it I'll stick an uprated clutch in and remap for more torque. Didn't yours do 235 and high 300s?

I thought the 1756 was roughly the same output as a hybrid pd150 at around 2 bar and 230ish bhp and 350+ lbft.

Could be wrong though.

If you have a GTB turbo you really do need to fit upgraded injectors, if you haven't already

I thought standard injectors were good for 240+

I thought standard injectors were good for 240+

They can be pushed to 240+ but you'll soon be melting pistons due to the long duration. 220/230bhp is the safe limit.

The chart on Darkside website says 230bhp @ 31psi.

 

Mine was initially mapped and went on the rollers and did 240 bhp and 350lbs torque, it was over boosting and smoked a lot though, I think 210-220 bhp is more realistic on a low smoke map @ 2 bar.

As above imo

Injectors aren't needed for a 1756,and would be a waste of money and make the car a horrible smoke belching thing

Phil Cooper at TRP Developments recently tested one and found that particular unit was only capable of holding around 1.8 bar and around 215bhp

And there seem to be a lot of problems with these turbos, maybe it's just one supplier in particular but I have not heard about anything negative about the Darkside one or even other companies such as Turbo Dynamics

Agree plenty of poor gt17 hybrids out there.

A stock gtb1756vb is a cracking turbo as is a stock gtb2260vk.

From the title I took it the poster was talking about a standard GTB1756vk not a hybrid.

It is a GTB not a hybrid.

I'm thinking replace clutch with uprated item, new dmf and then remap for the extra torque that it will hold.

I know the current map is a clutch "friendly" one, so for the sake of argument say it's 300ftlbs. If it was pushed to 360/70 that's a 20% increase in torque. Surely that will be noticeable.

I've ran a GT1756 hybrid at 235bhp and 340lbft on a brand new standard Sach's clutch and flywheel, both changed about 2 months earlier and no slipping at all

I'd say around 340ftlbs is realistic and around 235-240bhp depending on dyno. That's at 2.2-2.3bar.

Don't fall into the dyno lottery. How it drives is what you want.

Edited 30 September, 20169 yr by faboka vrs

Thanks for the info folks. I'm leaning towards an xman clutch and a new sachs dmf. doesn't sound like my turbo is going to go an awful lot higher than it currently is so anything more extreme clutch wise is likely to be wasted unless I went for a bigger GTB.

Iirc the person that remapped it said it was at its limits of around 2.1 bar or something as I was disappointed with the figures.

The GT1752 hybrid remapped better than the GTB did.

People saying their at the limits is all guess work. They don't drill and fit turbo speed sensors to monitor the rpm their running at then use the compressor size to calculate air tip speed. Or calculate the ve of the engine, calculate airflow then plot it on the compressor map.

It's all *******s

Iirc the person that remapped it said it was at its limits of around 2.1 bar or something as I was disappointed with the figures.

The GT1752 hybrid remapped better than the GTB did.

You mean the one I've just sold ha ha

Can you remember the figures as Davey can't. Who forgets how much power their car makes ha ha

Yeah, the one you sold mapped well, Daveys not as much.

Safe limits as in xman said 2.1 bar max and that's what it was running (for example)

Yeah, the one you sold mapped well, Daveys not as much.

Safe limits as in xman said 2.1 bar max and that's what it was running (for example)

I know mate. It drove better too. was planted at silly speeds. This one is a bit wayward. I was telling the lad that bought it I feel like I sold the wrong one!

I'll get this one sorted. Just time and money ha ha

That's a shame, Davey spent a lot of money on handling modifications as well.

Maybe try some better tyres on the front.

I swapped my Wheels and tyres across and it made no difference. I've got a clunk somewhere over bumps. Hopefully it's that. Passed its mot like. Meh I'll find it.

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