NITROUS OXIDE ( nos / n2o ) advice forum

Hi guys,

My name is Ross and i am from Dunfermline in Scotland.

I own a 1996 Nissan Pulsar GTi Autech edition, which is an import version of the UK almera GTi.

It was factory tuned by a company in japan called Autech and stock it makes 170hp from a 2.0l engine. (as well as being fitted with a LUDICROUS bodykit!)

I bought the car last november and had 2 months of non stop problems which tested the limits of my mechanical ability, but i am now happy i have the car running and looking top of its game.

I recently bought a WON 150i kit from Lawson at Powerhouse UK (recommend him to anyone!)

so here is some pictures of how far i have come so far.

how i bought it:



unfortunately i got a months worth of use out of it before i was rear ended on the first day of the heavy snowfall on my way to help a friend who tried to clear his windscreen with the wipers so the car spent the next month sitting in my drive where it decided it didnt want to live again. once the snow thawed i got back to work trying to get it running, new battery, new HT leads, new spark plugs, new fuel filter, new starter motor until finally discovering this :



after the insurance payout was agreed i got to work repairing it, i like my ghetto mechanics



and blew my insurance settlement on a full respray



got a 2.5" exhaust custom build and fitted and fitted 4-2-1 manifold





and finally more recently i bought this



I know the car and its cosmetics may not be to everyones taste but i have kept it as the tuning company intended and i love it!

current specification:

2.0l NA motor with 7.5k rev limit (factory)
265/11mm camshafts (factory fit)
11.5:1 Compression ratio (factory)
ported head (factory)
full 2.5" stainless exhaust mated to the factory Fujitsubo backbox
A'Pexi Dual funnel intake
Fidanza 8lbs Aluminium flywheel (stock is 18lbs)
LSD transmission (factory)
Daiyama Coilover Suspension
Energy Suspension poly bush kit
custom 4 wire O2 sensor (prevents richness caused by misreading the signal from bad ground in the stainless exhaust)
Whiteline rear sway bar

at the moment it should run the quarter mile in about 15.0 seconds (i race at crail, anyone thats been should know how bad it is) and i hope to drop into the 13's with my nitrous kit which i will be fitting this weekend.

Thanks for reading and i hope to stick around on this forum

hiya
The street sleeper phrase comes to mind, which is what all good wolf in sheeps clothing cars should look like,goods times too

Welcome to my forum and thank you for choosing WON.

I look forward to seeing your pictures of the finsihed fitting job.

Well after numerous setbacks i can officially state i am now running a WON kit on the pulsar!

I had a real headache getting nitrous in the bottle, anyone up here that USED to supply it, no longer does.

So I went with Nitrous oxide supplies, which again led to numerous - courier related - headaches. got there in the end and i cannot praise Si @ N.O.S highly enough, fantastic communications throughout and never hid from the problems with the courier.

All in all it took me about 5 hours to plumb in the system and wire it up from the beginning to the end, but the instructions supplied were crystal clear and very descriptive, so never had a moment scratching my head wondering what to do next.

My only stumbling block last night was i couldnt get the pulsoids to fire, no matter how i set the TPS unit. so i retired to sleep (read : lay awake pondering) and took another stab at it tonight after work. turns out where i had took the +ve feed from behind the dash wasnt a strong enough voltage. so wired it into the cigarrette lighter and it worked first time.

Currently i am still running the Jets corresponding to a 25hp increase, but already there is a massive increase in acceleration, despite a small amount of "lag" as the nitrous comes on, which i presume is the definition of the instructions described "smooth surge of power"

All this came together in time very nicely, with a drag day on sunday (as long as the weather holds!) to show what it can do. I'll be taking jets with me to increase to a 50hp shot, as well as BKR7EIX Irridium spark plugs as a safety margin.

Before Ii do any more increases I will be installing an MSD ignition blaster and a Greddy MSS (multi switching system) with the MSS allowing me to activate both the MSD and the pulsoids in sync and limit the activation to above a specific RPM (bit of a further safety margin for the engine)

I'd like to thank everyone on this forum who has answered my newbie questions since i joined and hope to continue to gain knowledge from you guys while i am here.

A specific thanks goes out to Trev for designing such a great system and Ant for assisting me with figuring out the old style TPS switch. i've never for a moment felt alone when buying or installing this kit.

onwards to the drag strip!

(PS. i'll get some install pictures once i tidy away the wiring!)

Glad it's all come together for you and that you're happy with the assistance provided.

I raced at crail raceway today with the following results.

When i raced last time, i ran a 15.20 @ 90 mph.

First two runs this morning were done with a 25hp shot and some slick tyres and ran a 15.42 @ 92mph. (ill explain the decrease in a minute)

After the two runs I switched the jets and spark plugs over to run a 50hp shot, again with the slicks and ran a 14.83 @ 100mph

Finally, in order to set a time for our owners club i ran on street tyres, 50hp shot, 14.76 @ 99mph

Seems the slick tyres i was running werent doing me any favours on crail's rough surface, as they were more just being shredded than actually getting heat into them.

Unfortunately the extra torque of a 50 shot proved too much for my stock clutch to handle and it started slipping. So my next purchase will be a heavy duty ACT pressure plate.

oh well i've had this fitted for a week now and this is the first time i have remembered to take some snaps while it is light...

wiring is a bit messy but it is solid, i hate wiring and it will be getting relaid soon










so i started off fitting the kit with a 25hp shot set up. I done two runs at crail then at the side of the track the AOC pit team got to work upgrading to a 50hp shot, as well as going to BKR7 plugs.



static test indicated that the jets were good, revving up to within 1000rpm of the redline back down the strip and the first run i take an instant 0.5 second off the time, however there was slight top end Det present, back to the pits, timing gun out and knock it back to 15*

Another run down the strip and the det has gone, but the time only improved by a tenth. however the torque was insane.

Back when the idea of nitrous first crossed my mind and i was talking to one of our club legends, dave bull to get information and he mentioned he had something from his long gone WON days that would suit my needs to go bigger and higher power.



MSD ignition system. when activated it will retard the ignition timing by a preset amount, which is set based on the amount of nitrous i wish to run. this allows me to run higher shots without having to retard the timing across the range, thus keeping the autech's natural power when off boost, and allowing safe power on boost.

This will all be controlled by a Greddy MSS, which will do 2 things.

1. Prevent nitrous activating too low down the RPM range on harsh launches (Bad times, im sure you all know)
2. Automatically activates both the MSD and the pulsoids at the same time. ensuring the ignition is kept safe at all times.

ok so went to the dyno this weekend!

Story time.

arrived high spirited, would be happy with stock power (170hp) and stock + 50 for nitrous.

first run, brings it up and boots it to the wonderful figure of 141bhp. to the words from dunc "thats f*****g s***e!"

second run, boots it and lets it chirp off the limiter and reads 145bhp. still. not. good.

third run, up to 3k, hits the gas switch and the power flies up to 180bhp with a distinctive buzzing noise from the exhaust... DET. fudge!

fourth run i brought the timing back to 15* and done a run without gas, 161hp. so for some reason retarding the timing in this case gained power. thats really quite odd!

fifth run, nitrous brought in at 4250rpm, instant spike up at that point on the graph from 100hp to 155hp and continued climbing all the way to 198hp. with a maximum torque figure of around 190ft.lbs.

sixth and final run, brough the nitrous in earlier to give it a little more time to overcome any lag and revved up to 6500 before that buzzing noise came back with a vengence. more det. netting 191hp peak

the next 20 minutes were spent discussing where to go from here. im advised to tighten up my plug gaps from 0.9 to about 0.7-0.6mm to give a better spark, and use copper core plugs to instill a safety net (copper core plugs will fail before the engine does, my irridium plugs will still be working after the pistons have melted). where det presented itself the AFR reading was around 10:1. VERY rich, which dunc reckons is a result of the overfuelling quenching the plug. Also i reckon i inadvertadly put regular fuel in. which would explain my low NA power and my detonation on gas, since my car is factory mapped in japan to 98RON

Videos:

Listen for det :

[video=youtube;UoozooDXSpo]http://www.youtube.com/watch?v=UoozooDXSpo[/video]

No Nitrous :

[video=youtube;Zl8ulVY_X8w]http://www.youtube.com/watch?v=Zl8ulVY_X8w[/video]

Nitrous :

[video=youtube;3_ULTtkeUfw]http://www.youtube.com/watch?v=3_ULTtkeUfw[/video]

last one to try break the 200's. DET

[video=youtube;xOxWMDNqdzc]http://www.youtube.com/watch?v=xOxWMDNqdzc[/video]

Graphs:

Power:



AFR:



note he only revs to 7k with nitrous. im happy with my results overall, but happier with the knowledge i picked up during the day.

ill be going back in two weeks when i have fitted my new cams and upped the nitrous shot, to ensure everything is safe before i race on the 12th june.

Listen for det :

http://www.youtube.com/watch?v=UoozooDXSpo

No Nitrous :

http://www.youtube.com/watch?v=Zl8ulVY_X8w

Nitrous :

http://www.youtube.com/watch?v=3_ULTtkeUfw

last one to try break the 200's. DET

http://www.youtube.com/watch?v=xOxWMDNqdzc

Did you fit the MSD unit?

That indicates one of two probabilities;
1) The use of inappropriate fuel for the purpose.
2) The timing was incorrect/advanced at the outset.
If the latter, how are you determining the timing settings??

My timing settings are done with a timing light connected to cylinder 1, TPS disconnected, base idle set to the FSM 950RPM and timed using marks on the crank pulley.

Also i reckon i inadvertadly put regular fuel in. which would explain my low NA power and my detonation on gas, since my car is factory mapped in japan to 98RON
That would CERTAINLY explain things. Also grade 7 plugs are a relatively low heat range for nitrous use and therefore more prone to overheating and causing detonation than 8s or 9s, so I'd switch to 8s if I were you.

Thanks, I will give them a try if thats what the wizard recommends!

Better not to over rev a nitrous engine and you can always project the line from lower rpm to estimate what it would have peaked out at.

am i correct in thinking it is bad hitting the limiter on nitrous? can cause a backfire?

ill be going back in two weeks when i have fitted my new cams and upped the nitrous shot, to ensure everything is safe before i race on the 12th june.
In that case you DEFINITELY should switch to grade 8 plugs and if your engine will take plug types that have ECS after the number, those are the absolute best for nitrous use, or carry out the mod on BASIC plugs as described in my book;
http://www.noswizard.com/product_desc.php?id=97

I don't appear to be able to get ECS plugs for my engine, so i will be investing in your book before the next race day!

sorry trev i missed the first question, no, the MSD was not fitted at the time. it will be before i go any further though.

I personally have never had any experience with detonation, so i was relying on the information given to me by the dyno operator who is also a tuner. as well as a very experienced friends input on the videos. my ECU does adjust the timing based on load, but the base timing is set by rotating the distributor, so retarding the base timing 2* will retard the timing by 2* across the range. this has been proven by road testing with the car hooked up to a laptop constantly monitoring the ignition timing values.

I notice in my dyno graph the torque on nitrous starts to tail off at around 6500 rpm, i never thought of it this way but would you reckon that shifting at that point would decrease 1/4 mile times? due to as you say utilising the torque?

I have booked in for an hours dyno time next friday to allow me the chance to fine tune everything before racing. the dyno operator is a very knowledgable person with nitrous experience as well as honda / nissan tuning experience. when i go next week the plan is to get the Det cans on the car to have a good listen to what is going on, as well as fiddling with timing / crossfire angle / intake setup etc.

Well its been an interesting weekend!

after a few attempts i've ruled the MSD to be dud. so was going without it.

went to the dyno on friday to get a refill as well as some dialling in time before racing at the weekend.

first problem cropped up when the adapter to refill my bottle with a NOS refill pump had gone missing. so mad rush trying to solve the problem led to fabricating something up at my friends workplace which fit both the bottle and the refilling station. when we finally got it to seal on the bottle it started blowing out of the welds. so there was the first failure, a half bottle of nitrous.

started off doing an NA run to see what differences the new cams had made. made 165hp (a gain of 4hp, not great, but the engine is unmapped just now) but unfortunately the AFR's are a bit all over the place.

done another run, this time with a 50hp shot again, to see where we were at there with the new plugs. considering the low bottle pressure it performed spectacularly, but showed no gains over last time, reaching 199.6hp + 180ftlbs. now taking into account the lower pressure i presume the gains would be greater with a full bottle?

at this point it was 7pm and the dyno operator was doing me a great favour to try and push my results. so we opted to try a 100 shot, with a 100 fuel jet and a 200 nitrous jet to get a nice safe ratio. the revs began to climb and we brought the nitrous in at 3500 rpm, the power and torque spiked to over 150 of each before the graph done a backflip and the engine started to missfire. a result of the lack of gas remaining in the bottle.

at this we called it a night as there was no further we could go without a full bottle, so i was resigned to using a 50 shot over the weekend. fortunately a fitting to allow my bottle to be filled was found on saturday morning, so i wasnt running on empty. managed to bring my personal best down to a 14.6 @ 99.3mph. ranking 16th out of 80 in the FWD catergory. i reckon with the car tuned properly, still with a 50 shot i would have ranked in the top 10.

the car is getting booked in to be fitted and mapped on a nistune daughterboard next month to bring my natural aspirated map up to key. so fingers crossed next time on the dyno i will crack the magic 200hp mark. and can get further towards my 13s quarter mile target.

on a side note, former WON customer dave bull took fastest FWD on sunday with a 12.09 in his almera turbo, he used to run a WON kit 7 years ago, and was the motivation behind my project now.

I've also got a copy of trevs book now and have read it cover to cover 3 times!

Shame about the problems but it sounds like you'll get there soon enough.

BTW do you know why the other guy stopped using our system?

he basically got on with his turbo build, which ended up at 500hp and 450ftlbs. thats already 100ftlbs over the highest rated SR20 gearboxes tolerances and he went through 3 before finally finding something to suit his needs. which turned out to be a cryo and shot peened box, running lorry diff oil.

so at the time he basically decided he had more than enough power from a big turbo and sold on the WON kit.

he ran a 13.47s quarter 7 years ago on nitrous and nobody in the owners club has beat it since without a big turbo. and I am the only person in those 7 years to take on nitrous oxide in this car. in fact nobody has come within half a second of it NA. and even the second fastest turbo motor is less than half a second quicker than the WON 100 shot he used.

speaks volumes for the effectiveness of nitrous oxide!

Thanks for the report.

had my first and hopefully last experience of a nitrous backfire last night






combination of lack of attention and forgetting to disarm the system after use, planted the foot to get up a steep hill and activated the nitrous. i felt the surge too late to do anything and it backfired like a gunshot.

blew a mount in my bonnet as well as the above damage.

Sorry to hear that but that's a classic mistake to make. I take it that you don't have a Max Extreme, because if you had it would have been possible to avoid or at least minimise such a situation.

Keep in mind the Max is NOT just about control, its also a SAFETY device.

And just think when a american system backfires it tends to be log-fire time on youtube

There's a BIG difference Ted, as the only time my system will backfire, is due to operator error (as in this case), whereas US kits more often than not CAUSE backfires due to inadequate 'design' and/or failure.