NITROUS OXIDE ( nos / n2o ) advice forum

I'd love to show you the graph, but my printer/scanner has failed.
The important figures are:

Stock produced 302HP @ 5700rpm
& 340ft/lbs @ 3700rpm

We then ran the 150 shot, got some amazing results, but also found that reving passed 5000 was NOT possible. After consulting with WON, we believe the spark is failing at that point, so peak HP was NOT achieved. I will be reducing the plug gap in an attempt to rectify this.

Here are the results we DID achieve with the 150 shot:

525ft/lbs torque @ 2700rpm
Throughout the rev range (2000 - 4800) the engine was up approx. 100HP until the revs failed at 4800.
At 4800 we achieved 366HP, whereas in stock at it was 280HP.

We were also able to prove that the engine ran best at -6 retard, with the 150 shot (as per Trev's guidlines).

If the smaller plug gap allows the engine to rev to 5500, in excess of 400HP will be possible, but more importantly, it will enable the car to auto shift as at the moment I can only manual shift as the lack of revs prevents the auto up-shifting.

Watch this space

NEARLY there Rich!

Hi Rich.

Did you have the same problem with the engine Reving past 5000 on the track/road? What heat range spark plugs do you have now? NGK calls for heat range 6 for the stock M62.

Cheers
Hadi

Hi Hadi,

Yes, I had the same problem on the track, hence I have been shifting manually at approx. 4500.
For plugs I am running Denso Iridium IK22 (1 grade colder than stock).

In previous tests I was able to rev to 5500 with 50 shot and the car auto shifted as expected.
WON believe it is the increased cylinder pressure that is causing the plugs to fail, so the simplest solution first, is gap reduction.

I had the same problem on NGK's, that's why I tried another plug.

How tight was the gap on those plugs? Also what heat range on the ngk's? May i suggest running a -7 gapped to .25. That should get you in the ball park. I'm not familiar with how strong your cars factory ignition is (or is it aftermarket) are but you might even have to go as tight as .2. Best of luck. Here's a good lil article about plugs, there's some links to others on the bottom of the page as well. http://www.dragstuff.com/techarticles/h ... plugs.html

Many Thanks, thats exactly what I was hoping to hear.
My set-up is that I have 8 standard coil packs (1 per plug)
In the next week or so, I will be re-gapping the plugs. (WON also agree with re-gapping).
It takes about 2 hours to do the job on the 840, so I need a warmish rain free window (I don't have a garage)

Cmon Rich - Wheres the racing spirit?

If its dry then we 're racing.......

If its wet we work on the car.....

- I dont have a garage either just an old gazebo.

I think you let me off lightly.
I knew I'd set myself up for grief as soon as I hit SUBMIT

Well what else are friends for........

Don't those cars have ginormous hoods??? It can't be raining with your head under there!

Yeah, but my back and arse will be sticking out
MY girlfriend has joined in the piss take now, thanks guys

I'll be rigging up a tarpawling next weekend

Removed the plugs this afternoon and ALL 8 are set at 0.075.
As advised they will be re-set to 0.025 and the test drive is tomorrow.

If the plug gaps sort the rpm issue Rich, you will be well on the way to record runs this year mate

I bet you wish you had never met me now eh ???

Wow. ya that was a large gap. I'm sure you'll have way better results at .025

Hi ALL, IT WORKED.
The Beamer now rev's to 5500 when on NOS and the gearbox auto shifts.
There was a slight misunderstanding on my part as I had my Metrics and Imperials mixed up.
The actual plug factory setting was 0.75mm which has now been re-gapped to 0.5mm.
To say I'm happy is an understatement
We're all set for the "Fast Show" in 3 weeks time and Vivienne WILL be driving

Great News Rich!

Hoping to make the morning of the fast show and use some gas but SWMBO may not allow me as I have to get back from the Rapid Yellow wedding event the day before and I did say I wouldnt race on sundays

Glad to hear it was something so simple.

Might be worth trying an IK24 or 27 next time as perhaps then you can get away without the regapping.

EXCELLENT!!