NITROUS OXIDE ( nos / n2o ) advice forum

I have a DSG gearbox with uprated bearings and a Quaife diff. The clutchpack is uprated by software for a higher torque handling capacity, but I'm at the limit and will need an uprated clutchpack eventually. No clutch slip yet!

Thanks john... i remember seeing (on youtube) alot about launch controlling the dsg box when i was interested in a golf purely for that feature

Went to USC at Santa Pod on Friday and now I'm in need of a few things doing to the car

Head gasket
Exhaust flange weld cracked
Clutchpack slipping
Uprating the fuel pump

engine is fine and the leak isn't bad, but enough to warrant a change to a steel one.

Drove home fine, but the exhaust is a little loud now, don't know if it was excessive pressure or heat though!

Clutchpack is the biggie - $1400 for a 500bhp/lbft upgrade set. I knew it maybe needed at some point though.

blimey john sorry to hear that, did you toast any top cars as compensation

The first few runs the system alarmed with low fuel pressure.

Then I got a run where the system alarmed about half way down which was a 12.8

Then it rained.

Once it dried out I had another run with horrendous clutchslip and the alarm tripped in again even though I'd upped the pressure regulator.

Last run I aborted as the car made a strange noise, which could have been either the exhaust, the head gasket or the clutch??

and im in a stew over a new paddle clutch sounds like another wallet hit for you john

SHIT!!!!

The first few runs the system alarmed with low fuel pressure.
Lucky you had the Max with the fuel pressure transducer to cut the nitrous system in the event of low pressure and by coincidence one of the guys from the other (Golf) forum PM'd me saying he was interested in a system but believed the fuel system was only good for 425 ish BHP and I responded by saying that it didn't seem to be the case on your car but now it seems it is.

Then I got a run where the system alarmed about half way down which was a 12.8
Naughty, naughty, because you should have stopped using the nitrous system once it had indicated inadequate fuel pressure but no doubt the desire for a quick run drew a red mist over your eyes.

Then it rained.

Once it dried out I had another run with horrendous clutchslip
Strange that it should perform so badly without any prior indications of having a problem.

and the alarm tripped in again even though I'd upped the pressure regulator.
Changing the pressure regulator setting wouldn't have any effect, because the cause of the problem is lack of delivery TO the regulator not the flow from it.

Last run I aborted as the car made a strange noise, which could have been either the exhaust, the head gasket or the clutch??
Just glad to hear you made it home OK and that the engine itself is fine and most important of all to me, is that the nitrous system performed as it should both in delivering the power and cutting off in the event of inadequate fuel.

Shame you didn't get at least one good run in before it all went pear shaped but we all now know where the limits are on your particular vehicle and that's knowledge worth having that at least others can be accurately warned about.

With the benefit of hindsight, it would have worked out better for you if you'd started the day on lower powered jets, that both the car as a whole and in particular the fuel pump, could have handled better.

BTW the guy on the other forum seems to think that upgrading the fuel system isn't an option (for some reason), so if you have any difficulty with that I'd be happy to assist.

We can also offer you an INDESTRUCTIBLE head gasket that will handle DOUBLE what you currently have, so you might like to consider that as an option. The only drawbacks are that they are not cheap and can take a couple of months to arrive.

Cheers Trevor,

The clutchpack is $1399 from SSP and will be around £250 for fitting (DSG oil on its own is £100!!)
The headgasket will most likely be done with rods and pistons, so £2500 all-in for that.
The Exhaust, hmm perhaps a 3.5" custom downpipe and rear to flow the extra gases.
The turbo - I may hybridise the K04 as it would then flow another 20-25% more air.
The fuel pump - a sticky one this as there are kits that will increase the pumps ability by +50%, but they are a variable voltage type pump and supply on demand, so at idle they could prove to run very rich

These would allow me to run at least 100bhp nozzles reliably and the only sticking point is the pump......and obviously the outlay

Any news on progress?????

I've had a couple of PM's asking how you've been doing on the other forum, so I think it would help if you made a post there as well. I guess you're concerned about their reactions to the failures but it's not like anything went wrong, it was just that some parts couldn't cope with the extra demand and if anything it's impressive that you have the ability to exceed those limits.

BTW - one of the good things about nitrous is that you can reduce the power, so if you can't run to having the beefed up parts fitted soon, you could always reduce the jet sizes and manage with those for now.

Talking of reduced power,remember that slipping clutch of mine trev, well the new one is bedded in now and ive just tried a run,no slip you may notice the 1st and 2nd gear dips its because of the rev limiter its like hitting a brick wall ,i need to learn to short shift oh and the bottle pressure never got above 800

update, dave told me about the screw on the bottle sender doh! anyway she purring at 950psi now OMG what a difference ....i cant stop the car actually tried to lift itself of its mountings l

Excellent!!!

Hi Trevor.

It looks like the transmission oil overheated and caused the slippage of the clutchpacks. I'm running on 50bhp jets at the moment, but have also sealed the gasket temporarily with "Steelseal" until I can get the car in. The gasket needs replacing, but doesn't leak under normal running. The exhaust should be good for 500bhp (so I'm told) and has now been fully repaired.

The uprated pump should be okay, so I'm going to give it a whirl when I can get the car in.

Here are a few graphs I've done comparing VW Golfs.

Time on my hands, so put up a quick comparison between my OEM K04 on 100bhp Nitrous versus APR stage 3 with a GT2871R. Both runs done on the same Dyno Dynamics rollers.

Nitrous on mine was brought in at around 3300 rpm.

The difference between 3250rpm to 4250rpm varies between 101bhp and a massive 160bhp and then the APR car gradually closes the gap, but is still over 40bhp adrift at the top of the rev range.



Also thought I may as well do a comparison of torque between my Stage 2+ OEM K04, My OEM K04 on Nitrous and APR stage 3.

As you can see the K04 has much more torque low down in the rev range compared to the Stage 3 and doesn't really lose too much at the top end either.
The Nitrous however, is again impressive with a peak of over 500lbft at 3800rpm against the Stage 3 at 280lbft at the same point.

Again this is bringing in the nitrous at 3300rpm, so bringing it in even lower in the rev range would accentuate it's benefits even more.

EXCELLENT info!!

So if I understand the graphs correctly, progressing down the turbo route costs you low end torque for a few more BHP, just as it does when you progress down the NA route with bigger cams etc!?!?!

Not being a turbo expert and being so busy understanding nitrous, I wasn't aware of that if that is the case.

That is correct Trevor and the situation with low down torque gets worse as the turbo size increases. The ideal combination in everyday driving for a 2.0 would be a medium size turbo (like mine) with plenty of nitrous or for a complete animal for the track, a larger turbo with nitrous lowdown in the rev range to help spool and reduce the torque hole

I think exhaust flow will be the limiting factor on my turbo as it doesn't have an external wastegate for quick removal of gases.

I was aware that much bigger turbo's that made substantial power increases resulting in less low end torque/power but I'm surprised that such a big loss at the bottom end is the price for such a relatively small increase at the top end, as your graphs show.