NITROUS OXIDE ( nos / n2o ) advice forum

Howdy all,

Hope everyone is well?

Been a little quiet from me as I've been sorting various issues and working like a madman whilst the going is good!

Now the F is going in to Emerald middle of next month to be mapped with the new supercharger and hopefully bring the power up to the theoretical bottom end limit of 220bhp (0-60 in 5 seconds ). One question that keeps going around in my head is about the nitrous. I'm now running a DP system with Minimax but am not sure whether it will be safe to run with the engine already on it's theoretical limit. Thinking mainly Santa Pod and short bursts as opposed to long runs.

Any thoughts/advice?

If not then I'd best get saving for the forged bottom end.....

Cheers

I've pushed STOCK bottom ends to MUCH HIGHER power levels than 'experts' have claimed to be the upper limits and NEVER had one suffer damage in THIRTY FIVE YEARS, so I very much doubt that's going to change in your case.

The normal causes of bottom end failure are;

1) Shutting off from high rpm due to lack of damping of the inertia loads stretching the rod and bolts
2) Detonation

NOT actually generating big power figures.

Furthermore, the higher the rpm range you use the higher the inertia loadings on shut off, so its possible to reduce the risk of engine failure by reducing the peak rpm and LUCKILY for you, nitrous will not only allow you to do that while STILL improving performance but you'll actually benefit from using a lower peak rpm, as it produces more torque and even better performance.

One final point to keep in mind, is that the engine is only subjected to peak power forces at peak (or close to peak) rpm, so even if you still pushed to the same peak rpm, as long as you either shut off the nitrous or taper it off in such a way as to prevent the power at any other rpm level being any higher than at peak rpm, even IF 'MAKING' peak power any higher was a problem, you could STILL use nitrous to achieve enhanced performances.

Thanks Trev

It sounds like an RPM window switch to limit the nitrous to below 5k (redline @ 7250) should hopefully do the trick then until I can put the forged 1.9 block together

Can the minimax do this?

That would be a definite safeguard but you'd need a Max Extreme to have that feature. We currently have one or two used Max Extreme V1's available at roughly the same price as a new Minimax, so one of those would be your best bet, as you're getting A LOT MORE for your money, as well as it offering the rpm window switch feature.

Dan!

Two mates of mine just stripped an F to the bare bones and it ran a 14.8 two weeks ago on road tyres

My friend (and former WoN member) Debs Evans ran a 14.1 with a 75 shot via a Minimax on road tyres a few years back. The MG took the 75 shot all day long with no problems apart from wheelspin

It sounds like yours is going to fly mate

Pel

Thanks Trev, I might be in touch about that and a few other bits shortly



Hi Perry!

14.8! I barely ran that with the gas

Debs, now there's a name I haven't heard in a long time. Never had the pleasure of meeting her but her posts over on the Mg-Rover forums were something else, such knowledge and a great sense of humor.

I had to phone Emerald today to cancel the mapping session as the car has almost been condemned with various issues Because of that I'm now moving things forward and starting work on my Scholar 1.9 forged build. The old green N reg F that I've got will be brought out of retirement and built up with all the toys whilst I use something else for my day to day runabout. Hopefully then there will be no worries about chucking a 200+bhp shot down it's neck along with the 'charger

Got a lot to research and bits to buy so no doubt I'll be back with lots of questions

Debs is a nutter and I love her

She doesnt suffer fools lightly and she speaks her mind !!

That makes 2 of us Perry, so when did you last speak with her and how is she and what is she doing nowadays, as I haven't heard from her in a few years now?

You're not wrong there, she shut a lot of people up with one post I will never forget

http://forums.mg-rover.org/showpost.php ... stcount=22

I don't think I ever saw another fool mention "back pressure" again

Funnily enough Trev! she popped into my place on the off chance just before Xmas. But I was in London at work. She is now working in the home care sector I think. I should be meeting her at the Pod later this year I'm hoping she will have another drive in the MG for me as she is about 10 stone lighter than me. I just need to stop her backing off during the gear shifts

That is one of Debs Polite replies Dan !

You should see her when she has her feathers ruffled She is a very clever woman and has been through a lot, which is why she doesnt waste time on bullshit. Ex fighter pilot, she has a few PhD's and has been published in medical books many times. I do believe that some of her publications are still used as training documents in the medical world. She is one smart cookie for sure. And dont even get me started on her engineering expertise. Dont tell her I told you because she does not like to blow her own trumpet.

Thanks for the update Perry and I'm very pleased to hear she's well. Please give her my very best regards when you see her next.
I'm sure she'd take at least a couple of tenths off your time if she could keep her foot down. ;-)