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When to hit the switch
http://nitrous-advice.org/viewtopic.php?f=15&t=3263		 Page 1 of 2
Author:  MikeT [ Thu Oct 11, 2007 9:27 pm ]
Post subject:  When to hit the switch
I'm just thinking (dreaming again) ahead to when I get my kit installed (and presuming it can provide adequate amounts of fuel)...

Currently the engine struggles below 2.2Krpm, while the turbo begins pulling @ 2.4K and is on-song at 2.8K right through to 4.2K. The redline is 4.8K. I've roughly timed 0-60 as being a warp factor of 11.98s :lol:

1st gear is too short and struggles for traction as it is, so I plan on activating (non-progressive 30hp) for the whole of 2nd & 3rd gear which would take me up to 70mph. Does that sound ok or too risky? Would it be too stressful to use it in 4th (at any revs)? 5th must be a no-no?

Apart from something breaking, are there ways to tell how far you can push the engine? I've been told these XUD's can easily handle being tuned to 200hp without problems and Trev indicated it should withstand up to 150hp nitrous (progressively I assume) so just 30hp non-progressive shouldn't be much of a problem should it?
Author:  hondagirl [ Thu Apr 01, 2010 12:31 am ]
Post subject:  Re: When to hit the switch
you should be fine, I would still pull some ignition timing for safety. My rule of thumb is pull 1 degree for every ten hp, although I think you would be fine with 2 degrees being pulled because you are wanting to run so small of a shot. good luck ;)
Author:  Brett928S2 [ Thu Apr 01, 2010 1:13 am ]
Post subject:  Re: When to hit the switch
Hi :)

Trev will let you know but it sounds fine to me although you need to set WHEN the Nitrous comes in for the same reason you do not hit the Nitrous when going up a hill at low revs...

If you are controlling the Nitrous with a WON controller , and its a WON system you do NOT need to retard the timing at all, thats one of the huge differences between Won systems and most American systems.....

Even on my 928, I do not even retard by 1 degree of timing....

I am sure Trev will answer this and other threads as soon as he has settled back in the Uk (today) and had some time for his family and to relax.... lol

All the best Brett :)
Author:  hondagirl [ Thu Apr 01, 2010 1:30 am ]
Post subject:  Re: When to hit the switch
Brett928S2 wrote:
Hi :)

Trev will let you know but it sounds fine to me although you need to set WHEN the Nitrous comes in for the same reason you do not hit the Nitrous when going up a hill at low revs...

If you are controlling the Nitrous with a WON controller , and its a WON system you do NOT need to retard the timing at all, thats one of the huge differences between Won systems and most American systems.....

Even on my 928, I do not even retard by 1 degree of timing....

I am sure Trev will answer this and other threads as soon as he has settled back in the Uk (today) and had some time for his family and to relax.... lol

All the best Brett :)

I would like to know how you dont have to pull timing. I am not doubting you at all but how is this possible unless you add octane.
Author:  BMW840 [ Thu Apr 01, 2010 1:37 am ]
Post subject:  Re: When to hit the switch
One thing that's on our side is 99 Octane fuel, which is available almost everywhere.
That definitely helps.
Author:  Brett928S2 [ Thu Apr 01, 2010 1:43 am ]
Post subject:  Re: When to hit the switch
hondagirl wrote:
Brett928S2 wrote:
Hi :)

Trev will let you know but it sounds fine to me although you need to set WHEN the Nitrous comes in for the same reason you do not hit the Nitrous when going up a hill at low revs...

If you are controlling the Nitrous with a WON controller , and its a WON system you do NOT need to retard the timing at all, thats one of the huge differences between Won systems and most American systems.....

Even on my 928, I do not even retard by 1 degree of timing....

I am sure Trev will answer this and other threads as soon as he has settled back in the Uk (today) and had some time for his family and to relax.... lol

All the best Brett :)

I would like to know how you dont have to pull timing. I am not doubting you at all but how is this possible unless you add octane.


Hi :)

I will let Trev explain fully, but no I do not add octane, I just use normal 98 Ron pump fuel (Shell V-Power)

But the basic answer is that on a "well designed" system (WON I mean) there is no reason at all to pull any timing....

My compression ratio as an example is 10.5 /1 ..and as I said... I have never pulled (retarded) any timing...not ever.....

On my Porsche its NOT easy to do anyway, although I do have a "link wire" for using bad fuel which IF I connected it, it would pull 6 degrees of timing but never bothered to use it...

I cannot see the point of retarding an engine (losing power) to then use Nitrous ...(increasing power)

Trev thinks the same which is why he designs his systems as he does....

All the best Brett :)
Author:  hondagirl [ Thu Apr 01, 2010 1:45 am ]
Post subject:  Re: When to hit the switch
the only ways I am aware of to avoid pulling timing is octane. I have seen people run 25% increase without pulling timing although they do get knock still which is an indicator of predetination. Not a serious form but it is a small amount of predetination. I am very interested to know if there is another way
Author:  Brett928S2 [ Thu Apr 01, 2010 1:53 am ]
Post subject:  Re: When to hit the switch
hondagirl wrote:
the only ways I am aware of to avoid pulling timing is octane. I have seen people run 25% increase without pulling timing although they do get knock still which is an indicator of predetination. Not a serious form but it is a small amount of predetination. I am very interested to know if there is another way


Hi :)

As i said , no retarding and my Porsche has not even got knock sensors (too old - 1986)

And I am running way way over 100% of Nitrous/hp compared to my measly 350 hp of my engine (N/A)

I think you are basing your experiences on "OTHER" makes of Nitrous systems and not WON....

All the best Brett :)
Author:  hondagirl [ Thu Apr 01, 2010 1:58 am ]
Post subject:  Re: When to hit the switch
wow I just noticed this is a diesel topic lol There is no timing to even be pulled on a diesel. But I would still like to know when ever you get a chance. And yes I am basing this off of my experience with american makes. Although the reason I am so amazed is because all my experience says other wise. I am also well aware that pulling timing looses power, Although I have never seen anyone not pull timing. This has me very excited and I want to know how.
Author:  hondagirl [ Thu Apr 01, 2010 2:00 am ]
Post subject:  Re: When to hit the switch
you have got me sooooooo excited I want to convert to WON bad :twisted:
Author:  Brett928S2 [ Thu Apr 01, 2010 2:08 am ]
Post subject:  Re: When to hit the switch
hondagirl wrote:
you have got me sooooooo excited I want to convert to WON bad :twisted:


Hi :)

Off to bed now as 3 am here....

But I will say this, and then let Trev explain the rest....

I would guess that probably 70 to 80 % of WON users do NOT retard the timing....I mean ..why would we....a properly designed Won system does not NEED it and it loses power...

I am not saying by the way, that you cannot retard the timing with a WON system and in a few special circumstances its advisable.... but its NOT normal with WON....

Night now :)

Gone to bed.....ZZZZZzzzzzz........... :)

All the best Brett :)
Author:  rapidblue [ Thu Apr 01, 2010 8:25 am ]
Post subject:  Re: When to hit the switch
Oil Burners....... :lol:

Hi Mike -

30 bhp - should be NO problem ALL gears (provided you can get grip) The XUD's are a tough engine it would just be the box and I think that would be easily strong enough Citroens and Pugs are not known for weak gearboxes (unless your name is Gronholm).

From what I can see the limit to what gears you can use is down only to the tyres and gearbox being able to take the power, not to the engine which is just doing its thing regardless - if it wont take a 30 in 5th then it wont take a 30 in 3rd

As to maximum - more a fuel limit than anything on a diesel - not really sure. We have nearly doubled the bhp and torque - 228 lb ft to 450 lb ft with no issues except huge amounts of tyre smoke.
Author:  teddybare [ Thu Apr 01, 2010 8:41 am ]
Post subject:  Re: When to hit the switch
its about time you lot started talking about diesels again :D
Author:  culasse [ Thu Apr 01, 2010 10:09 am ]
Post subject:  Re: When to hit the switch
The only weak point of the BE 1-2, 2-3 or 4-5 gearboxes are their coarse spline or 18 spline input shafts. For some reason PSA doesn`t want to revert to a fine spline shaft.
You can solve this with a clutch plate with a wide spline shaft collar, as found on some OMP 4 paddle spring hub clutches. I have used these clutches to good effect and never had problems with it on the XU engines.
Author:  MikeT [ Thu Apr 01, 2010 10:10 am ]
Post subject:  Re: When to hit the switch
Teehee, not only is this the diesel section, it's an old post. :lol:

Having said that, it's sad that I've made little progress since then, mostly due to finance, lack of facilities and general circumstance but also due to deteriorating health restricting my mobility. I feel I've got one last chance this year so the car's booked in for it's MOT soon and if it passes, I'll make the effort.

HG, diesels do have timing but it's regulated by the fuel injection point. Like a petrol engine, tuning usually involves adding timing though I'm not sure of the wisdom of doing so with nitrous. By the way, you might want to consider buying Trev's book, it's worth it's weight in platinum just for the facts alone.

From the information I've gathered over the years, I think the limiting factor will be clutch and traction as rapidblue mentions and being front wheel drive, perhaps very limiting. As a result Brett, I decided to save up and buy a minimax to get the most out of my kit. Plus I do have a contingency plan should the drivetrain prove totally inefficient.

Fuel quantity shouldn't be a concern as these cars are severly detuned and the injection pump returns far more fuel back to the tank than is fed to the injectors. Even if it were, I can swap pump parts from other larger pumps for more flow. Being a diesel, I also have the luxury of being able to use many alternative fuels such as propane and alcohol, not to mention the fact it can run on vegetable oil, heating oil, even engine oil :P Talk about spoilt for choice.

Teddybare, I've said it many times and I'll say it again - diesel's are the future performance engines. They're decades behind petrol engines in R&D and if a heavy old pickup can do this... http://www.youtube.com/watch#!v=Gw4X86O ... re=related ....who knows where it'll end?

Although this video wrongly claims sub 9 sec's it does look like a sub 10.
http://www.youtube.com/watch#!v=mVq4FzY ... re=related

EDIT: Culasse, that's good information, thanks! What about the PSA autoboxes, due they also use coarse splines?
Author:  rapidblue [ Thu Apr 01, 2010 10:37 am ]
Post subject:  Re: When to hit the switch
Sorry to hear about the health Mike - just got back from the Osteopath meself. :beatstick:

We ought to get together and have a diesel only drag day or something.
We have thought about a tow car drag day for a laugh - all vehicles must have a tow bar but I think that a bit of cheating may go on - the Fabia has a tow bar and the Rapid is just waiting to have its one fitted!
Author:  teddybare [ Thu Apr 01, 2010 11:09 am ]
Post subject:  Re: When to hit the switch
yes mike, im looking forward to the gains i will see for myself when i start applying the nitrous ... funds stopping me so im attaching bits from trevs shop when i can afford them ,something thats always puzzled me tho ive watched alot of utube stuff why is it that all these very fast diesel cars and even dragsters pollute so much,i mean surely from what ive read ,it means thats just too much fuel and not enough nitrous.. :shock:
Author:  culasse [ Thu Apr 01, 2010 11:54 am ]
Post subject:  Re: When to hit the switch
[quote="MikeT]

EDIT: Culasse, that's good information, thanks! What about the PSA autoboxes, due they also use coarse splines?[/quote]

Unfortunately I never took a good look at the autoboxes Mike, so can`t comment on that.
Author:  rapidblue [ Thu Apr 01, 2010 12:23 pm ]
Post subject:  Re: When to hit the switch
It seems that a lot of these diesels use turbos rather than nitrous - although if the turbo is feeding enough air then they should be clean.

I think they are SO overfueled that even with huge amounts of oxidiser they are still shoving out soot. The black smoke so I am told is mostly un-burnt diesel
Author:  MikeT [ Thu Apr 01, 2010 3:52 pm ]
Post subject:  Re: When to hit the switch
Thanks for the good wishes Steve, I hope your efforts pay off. I've spent a fortune (thousands) on Osteopaths (even went to Harley Street at the beginning) Chiropracters, gadgets and all sorts to no avail. I've been back and forth between GP's and hospital consultants for decades with little to no worthwhile results for my efforts. There's not much I haven't tried as I'm forever the optimist but it's just the way it is. C'est la vie.

As for diesel only drag day - I'm on the south coast and would have to travel a fair way which again, is inhibitive cost-wise. Dorset/Hants is full of dis-used airfields so why we don't have our own strip is beyond me.

Teddybare, from what I've researched; like a petrol engine, diesels produce best power just slightly rich of stoichometric. Unfortunately, diesel soot production is exponential when going to "rich" side. It only takes a little over stoich to produce thick black smoke so I can only assume these drag racers run overly rich to ensure best power at all revs as, unlike a petrol engine, too much fuel isn't detrimental to power output (but it does increase EGT's to dangerous levels).

There's a saying that's spread among the internet dieselheads... "no smoke, no poke" but it's bullshit IMHO. The difference between a well-tuned, no smoke engine and black smoke is perhaps just a few percent of full power.
Author:  teddybare [ Thu Apr 01, 2010 4:59 pm ]
Post subject:  Re: When to hit the switch
interesting mike...i know its not drag strip power but my 320d remapped has never ever smoked and it really goes, and strangely the number of diesel cars that floor it to get away from me smoke ..one member asked if i had the particular filter ,which could be the reason ...well i havent mine is 2004 model so when i add nitrous it will be very interesting, because most diesel cars can add more because they tend to smoke ,i cant wait to see my results ;)
Author:  hondagirl [ Thu Apr 01, 2010 7:41 pm ]
Post subject:  Re: When to hit the switch
This is very interesting. I obviously have much to learn from you all and much to learn about WON systems. This system becomes more and more interesting daily.
Author:  teddybare [ Thu Apr 01, 2010 10:47 pm ]
Post subject:  Re: When to hit the switch
hey honda girl ,you can get a good laugh too if you look at my postings i was once teddy barred :mrgreen: by trevor...im famous really ;)
Author:  MikeT [ Fri Apr 02, 2010 5:52 pm ]
Post subject:  Re: When to hit the switch
Teddybare, was yours tuned on a dyno? Sounds like a good remap to me. Will you be adding fuel when you add nitrous or just see how it goes first?

I repeat, I'd strongly advise you get a copy of Trev's book Honda Girl, it is a very exciting read and at under £20, excellent value.
Author:  teddybare [ Fri Apr 02, 2010 6:43 pm ]
Post subject:  Re: When to hit the switch
mike im a bmwland refugee, so like here i did all the research from the day i was a bmw owner simon of emaps did my car ... hes the man, but in answer to your question no dyno, when i see the modern 330 e90 not being able to get away from me that tells me all i need to know ;) i will be looking to add fuel the day i find im limited to what just nitrous can do, oh and i take trevor to bed with me most nights , well his book i mean :D
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