Stavros

As title.

Im looking towards Chip I think on this one.

How effective is it?
How big a shot to be effective (say, on an 2.6 with a modern twin scroll 700-800bhp turbo/manifold setup)?
Im thinking either a 50 or 75 bhp shot would do it, but dunno, for all I know that may actually be too much,

I presume its easy with a pressure switch (like R5GTT overboost ones) to make it turn off once on boost.?
Im a bit worried that there will be a dip when it switches off, but guess if you can get the off time correct itd be ok?

As well as conventional nitrous injection, anyone got any knowlege or experience of injecting it in a different way?
Pre compressor for example?
I know its been done in the past like that, and the mega pressure nitrous comes out of a bottle would spool a turbo mega fast.
BUT would it still be liquid by time it hits compressor? If its not gas id not wanna do it as it will erode the blades too easy.
Also would need to inject the fuel much later, after the intercooler really. Would that cause any fueling issues?

What about direct into the ex manifold instead of engine? Im guessing fuel and air would be too violent a burn and blow the turbo/manifold tho...

Tim

iTrader: (1)

i use a 25 shot and its mint there is no substitute im sure chip will say the same

Turbosystems

iTrader: (5)

nos seriously reduces the boost thresh hold.
cue mike for a ten page argument

Mike Rainbird

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You'll have no arguement from me there - as I have no experience of NOS - but I think I would become an addict, so like skiing - I have always stayed away from it .

Turbosystems

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skiing !!! ?? mike
not something I would associate with the addictive power of nos cocaine addiction would be more appropriate

Mike Rainbird

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Everyone says, "Yeah I went skiing, it's so amazing, I now go twice a year!". I have enough expensive hobbies, I couldn't afford another .

Chip

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As above, even a small shot makes a big difference.

Two major effects:

The extra exhaust gas generated by the nitrous leads to the turbo spooling in the rev range earlier than it normally would, and faster when in the freshold

The nitrous gives you power while you are still lagging, so even though you arent on boost yet the car still accelerates anyway



Risks:

At low rpm (read as anywhere below the boost threshold) you risk running into a situation where you are at a point on the fuel and ignition map that hasnt ever been mapped as the mapper never had the vehicle make boost this low

If you put a lot of nitrous in you can get detonation as the timing is too advanced for it because the mapper has mapped for 50bhp of air only, not 50bhp of air and 50bhp of gas, as effectively when off boost your 50bhp shot is a 100% increase in power, where as at full boost it might only be a 20% increase in power or less, so is less likely to cause det (especially given the cooling effect and the fact most nitrous systems run very rich to be safe, well the ones im involed with anyway!)



Obviously those are just mapping issues though, and easily solved.


Both those risks are of course easily managed by a good mapper,

Chip

iTrader: (3)

My experience with nitrous is exactly the reason I have never tried cocaine in fact!

Stavros

Tim+Tony. That good is it? How big a difference does a 25 shot make? Making me think a 50shot would be fine in my application then.

Dont want boost from nothing, just fairly instant response from about 4000odd onwards.

It would be done in conjunction with the remap so thats not a big deal at least.

more like crack!

honest to god a quote from a mate and ex-crackhead the other day...

Bullett

iTrader: (2)

is NOS actually worth having on a high spec turbo engine,and more to the point is it really safe?
what sort of bhp shot would be considered safe and how does this work?

i know some are full throttle activation and some are switch so does that mean if its full throttle its on all the time if you are flat out or is this also switched?

i really dont understand it at all

Chip

iTrader: (3)

Pre compressor nitrous:

Terrible idea, it will be a liquid when it hits the blades but will be gas not a liquid by the time it gets to the engine, horribly ineffecient way for an engine to consume nitrous and an absolute cunt to try and fuel for, plus with regards to the blades it will lead to massive thermal shocks on the blades, which IMHO is just generally a really bad idea.



Switches for boost:

Works brilliantly.
When the nitrous comes on, its a big shove as its a big increase in power from no boost to no boost + 50bhp + radily followed by boost, once you are then on boost and making 300bhp anyway, the nitrous dropping off doesnt feel like such a big deal as it does coming on, if that makes sense?



Nitrous into the exhaust to spool the turbo
Ive never tried that, and if you did do it then you would be better off using Co2, as its cheaper and less likely to cause explosions

The reasons I havent done this are:
Thermal shock on the turbo at 1000C when it sees -150C nitrous would shatter the blades im sure
Greater manifold pressure would make the pumping losses of the engine greater, losing you power
It seems a waste when you could be using it in the engine to make power and then it still goes through the exhaust after anyway!

Chip

iTrader: (3)

If you have a 500bhp turbo charged engine, the only way safer to get it to 600bhp than nitrous is to replace it with a big v8, nitrous is SAFER than a bigger turbo would be, as it takes away heat not adds more.

Application specific, on a YB though, 100bhp is childs play

You normaly have an "arm" switch and a full throttle switch, only if BOTH are on does it activate

Hopefully now you understand it slightly at least, any more questions, just ask

Stavros

Cool, so a 50shot activated at full throttle and de-activated at i dunno, half or 3/4 of full boost, would be mint you think?

Chip

iTrader: (3)

Im a bit wary about this reply, as im having to really simplify things here and probably doing so to an extent its not totally accurate, but it should hopefully "get your head round" how it works.

Exhaust gas volume from nitrous burning with fuel is about 80-90% (i cant remember exact figure but its lower due to less nitrogen than in air) what it would be from "normal bhp"

So:
if your turbo needs to see 140bhp worth of exhaust gasses before it really starts to spool


off boost 3rd gear on the flat, 3000rpm, flowing 50bhp of gas (ie engine only making 100bhp at this point at most without boost and you are only at half throttle) the turbo is just overcoming its inertia and starting to spin very slowly but doing nothing useful, you go full throttle

With no gas:
The engine revs are slowly increasing cause it doesnt have enough power to accelerate the car hard so it cant build RPM, it slowly crawls its way up to 3500rpm, you are 4 seconds in and nothing has happened yet really, tiny bit of boost stars to creep in and then as you finally pass 4000rpm a further 2 or 3 seconds later aided by the turbo just starting to spool up, at this point it finally starts to make 140bhp, so is making enough exhaust gas to spool that turbo at last, the boost builds, as it does so the engine makes more power, the turbo spool harder, it all goes crazy



Same scenario with a 50bhp shot of gas on a boost switch:
Instantly the engine flows 140bhp worth of exhaust gas, the turbo starts to spool, as it does so thoug the engine is already acclerating up the rev range far harder than before as the nitrous is helping it, so you have 3 advantages, the extra gas from the nitrous spooling the turbo, the increasing rpm spooling the turbo as the engine flows more, and the boost thats appeared almost instantly also going through the engien and spooling the turbo, you reach 3500 within a couple of seconds, by which time the boost is at its peak and the nitrous cuts out, you've had 2 seconds of fairly hard acceleration anyway and now you are really flying.




Numbers all plucked from my head and not exact for any particular engine, but should get the point across.

Bullett

iTrader: (2)

Chip-3Door
cheers,thats making things a little better.there seems to be so much bullshit out there about this subject its hard to know whats what.so its nice to hear some of the guys who actually know talking whats right.

how come so many people say that NOS will reduce the life of the engine considerably and its prone to popping engines?
is this due to bad mapping more than anything?


so am i right in thinking if a car is running 500bhp and 100 shot of gas,when you have it armed and were to pull through the gears,say 2nd,3rd,4th it would be running 600bhp and then if you disarmed it in 5th it would drop back to 500bhp?

or are the 50/100 shots not a genuine gain but more like 3quarter of it?

Bullett

iTrader: (2)

also is it actually legal for road use or not?and do people insure their cars with it on?

Chip

iTrader: (3)

Same with anything

More often its due to bad nitrous kits, or badly installed nitrous kits.
Nitrous is less dangerous than boost, some people kill their engines with boost (think bleed valve and RST and no other mods) some people kill their engines with nitrous, thats just the tool used though, the real killer is the stupid cunt who thinks he knows what he is doing but doesnt.


Yes, well, it would be running approx 100bhp more at each point in the rev range, so if it made 400bhp @ 6000rpm and 500bhp + 7500rpm before it will now make roughly 500bhp @ 6000rpm and 600bhp + 7500rpm

Depends on the kit, the engine, and the amount you are putting in, but typically though I always expect to make MORE than the stated amount not less.

Also the gains in torque can be massive at lower rpm, 50bhp @ 2500rpm is 100lbft dont forget, but is only 30lbft at 7500rpm

Chip

iTrader: (3)

Perfectly legal for road use in the UK.

Some do insure it, some dont, same as a bigger turbo or set of alloy wheels or a large dildo fitted to the bonnet of the car that lights up and vibrates.

Stavros

Cool. So a 50 shot should be ok?

I mean to be honest, with good mapping it might be fine without, a 2.6litre straight 6, a 700-800bhp modern turbo with fairly small split pulse exhaust housing, and a divided T4 manifold (divided into 2 groups of 3).
Im only wanting decent power from 4000 or so on wards, its just the turbo is a bit of an unknown quantity, thas all...

I do want instant tyre shredding response tho, so this nitrous thing sounds a plan.

Wicked, I best get one of them too.

Chip

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50bhp on a RB26 motor is safer than wearing two condoms and making sure her old man isnt home.

And it will still be enough help spooling up, obviously more would help more though!

Bullett

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Chip-3Door
so who are considered good kits then? wizards of nos? and is it best to go direct into the fuel rail? going by what you say,if you had a good make kit,it was installed by a pro and mapped by a pro then you shouldnt have any probs.

do people in the ford scene map these systems often. i only ask as its normally associated really with the jap turbo's or n/a engines from other manufactuer's.

would people like stu,karl and martin do this work or is it not the norm for them do you think?

Stavros

Well id like to not use too much gas, as it costs money

I dont want a peak power increase, its on stock internals and turbo can give more power than the engine can take anyhow, want it for just ALS function.

Is it truly enough? Or is 75bhp a much better idea?

Tho in all honesty, changing the jetting is a 2min job anyhow, so can test that...

Chip

iTrader: (3)

90% or more of kits I have anything to do with fitting or helping spec etc are never in any way mapped, they are just setup to within the limits of the current map.

That isnt as restrictive as it sounds though, ive seen 268bhp on the rollers from a standard XE engine making 146bhp on the same rollers off gas for example! (so over 90% increase in power)

Wizard kits are without a doubt the best quality and are all I would recomend for smaller engined cars where you are looking for relatively large gains.

For 50bhp extra on a 400bhp V8 though, which is all most yanks do, the NX and NOS stuff is ok for that too, it just wont work properly with progressive control like I needed to see gains of nearly 100% on that XE I just mentioned.

Chip

iTrader: (3)

Thats a good question

And thats a great answer!



Bear in mind that more gas means it spooling even quicker though, which means the gas required for less time.

Ive tried 25bhp and 50bhp on a LET engine as antilag and the 50bhp spooled so much quicker before it boost cut the nitrous off that the consumption wasnt actually much different, although I never accurate measured it, was more like 25% extra gas used though not the 100% increase that might first seem logical.

Stavros

Ah good point, that thought sprang to mind too.

What sort of boost is best to cut it on? I know thats something to expererment with, but just wondering on your thoughts/expererments with it.
Half full boost, 3/4, full? Im guessing its best to cut it as the boost is still rising for a lesser feeling of power loss.

TBH with the turbo size and power im going for, doubt it will run more than I dunno, somewhere between 1 and 1.5bar, depends what is deemed safe at the time, like said, turbos a bit of an unknown to how it will perform on this engine.

Chip

iTrader: (3)

I cut it at 3/4 or more, but TBH the difference between nearly full and only half is going to be almost fuck all as once you reach 8 psi on that engine, at a point you are well into the threshold, you will be at 16 psi a fraction of a second later no doubt!

Stavros

Bullett

iTrader: (2)

Chip-3Door
thank you very much,i will keep reading this but it has helped alot.now its whether to go with the gas or not. if its safe and not an engine killer i may well do as not many fords run it.

Chip

iTrader: (3)

Got a picture of a skyline inlet handy?

IIRC the GTR is good for a single injector setup which should keep things cheaper and simpler.

Chip

iTrader: (3)

I only know of one ford thats died as a direct result of nitrous, and that was Rod Tarry's old engine when it made so much torque it pulled the block apart, it was still NOWHERE near melting or det or any other problem as it was setup very well by Mark Shead, it just exerted more force than the block could take.

Stu, and particuarly Karl and Sheady, have ALL used nitrous on the YB and any of them would be ideal for setting it up for you, im sure there are plenty of other tuners competent with it too, but those are ones that ive spoken to about it in the past.

I think all of the above will only use wizards of nos kits though, so bear in mind your choice of tuner when you decide what kit to buy.

Bullett

iTrader: (2)

Chip-3Door
you are a legend mate,i really appreciate all the advise.
as for rod's car,well thats a different ball game.he is in a league i could only dream of with that car.and you expect to get the odd failure when you are pushing the bounderies that far.

the only downside i may have is i may have to get custom driveshafts made if i want to run the quarters,4x4's tend to shit them

Chip

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Im afraid I dont know enough about the cosworth drive train to offer much advice there, but Brom makes stuff like that so might be worth a chat to him.

Bullett

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yeah will do,and mike r knows a bit too so im sure i will find something.

Stavros

Skyline inlet is renowned for having (even though it has a very fancy plenum) unequal flow front to rear, but wether that is another excuse for the piss poor "mappers" in the skyline world, I dunno.

I do want to run a single injector setup though, deffo, just to save on costs and pissing about.

About the pic though, in a pure bit of luck, ive a few pics of one in good detail, i kept it as i knew itd come in handy one day...





Im sure stupid PF pic resizer will make em smaller, but they are big pics if you cut n paste link into another screen...

GARETH T

ive never been in any car with nos

lead_foot

iTrader: (1)

Right click on the image and then click view image.

Chip

iTrader: (3)

Yeah, that looks fine for a single setup, put it about 4-6" before the plenum and make sure it corkscrews the nitrous/fuel charge rather than firing straight

Stavros

what you mean by that mate?

Chip

iTrader: (3)

I mean dont fire it straight, as due to it coming out at 1000psi or so, it will just all end up on cylinder six, so "corkscrew" it around the pipework so it gets a better chance of visiting each cylinder rather than go past it, plus it aids with mixing it with the air.

Stavros

So it shoots directly against the opposite wall of the boost pipe?
Or facing into (or away from?) the airflow slightly too?