metro6r4
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| posted on 25/10/14 at 06:30 PM |
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Nitrous oxide Vs Methanol injection
hi guys has anyone got any experience with methanol injection. I am starting to look into both methanol injection and nitrous oxide systems. However I
have my reservations about using nitrous as there seems to be as many risks as gains using it. I guess some information about my setup will help. The
car is a global gt light which is being used for drag racing. Currently I am having a naturally aspirated cbr engine fitted, running after market
engine management. The car is more or less being rebuilt from the rear bulkhead back. The car will run shell v power with added octane boost. The car
is being future proofed as much as possible ready for turbo charging when funds allow but at the moment I want to find out what is possible, what the
drawbacks are and how much money I need to stash away from when I go for my next round of upgrades.Any experience advice or suggestions on ever type
of system are greatly appreciated.
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snapper
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| posted on 25/10/14 at 08:48 PM |
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Methonal injection is more of a detonation prevention
Methonal as a fuel has the benefit of allowing very high compression ratios for big power but no use for the road
Nitrous has more oxygen so with more fuel will give a boost in power but for only as long as the gas lasts
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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Badger_McLetcher
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| posted on 25/10/14 at 09:50 PM |
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Typically I wouldn't think you'd use methanol injection unless you've got a forced induction set up or an ungodly compression ratio
- as snapper said it is a detonation prevention method. It's a similar story with octane ratings as well - unless the car has a high compression
ratio, or is FI and mapped to make the most of it, it'll not provide you any benefit. Nitrous also needs the fuelling to be sorted to make the
most of the extra oxygen.
If disfunction is a function, then I must be some kind of genius.
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MikeRJ
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| posted on 26/10/14 at 10:46 AM |
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If you want to make decent power with methanol then you'll be using it instead of normal petrol rather than injecting it on top.
Although methanol has lower energy content than petrol, the stoichiometric ratio is much lower, somewhere between 5:1 and 6:1 compared to petrol at
14.7:1. This means you inject about 2.5 times as more fuel, and you can also run a much higher compression ratio if you are running straight
methanol.
There are many downsides though; methanol is toxic (including exhaust fumes), it corrodes many metals, it burns with an invisible flame which is a
problem in the event of a fuel spillage, it's hygroscopic (attracts water) and it can break down engine oils. Fuel usage will be much higher
than with petrol, so you may need larger tanks. Obviously it's not as easy to buy as petrol either.
[Edited on 26/10/14 by MikeRJ]
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metro6r4
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| posted on 26/10/14 at 02:26 PM |
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I am going to be having the engine mapped on v power with added rock oil octane boost.
When the turbo install is completely planned out and I have the cash stashed away the current plan is to use methanol injection to allow a higher
boost setup.Boost will be set up on a progressive control system allowing difrent boost settings for each gear.I was planning on using 50% methanol
and 50% water.With the right setup I have been told that is hould be able to extract over 300hp using water meth injection safely and 400hp if I want
to push it.
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Ivan
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| posted on 26/10/14 at 03:08 PM |
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From your original post it wasn't clear if you were talking about methanol substitution for petrol or methanol + water injection into the inlet
tract to act as an additional charge coolant and detonation suppressant on engines that are running close or over the detonation limit.
For the latter water/meth injection is an excellent palliative to preserve your motor but won't in it's own right add power except by
enabling even higher turbo boost levels or reducing retard on the timing. You still need a charge cooler which in drag motors would normally be a
water/air type with the water tank filled with ice and water.
Nitrous on the other hand adds oxygen to the cylinder and demands sufficient fuel to to be added to burn that oxygen hence makes more power. It is
also an excellent charge cooler. Where it goes wrong is if you don't add enough extra fuel an/or retard the ignition sufficiently causing an
overly lean mixture and detonation destroying pistons. Provided you get the fuel/nitrous ratio right (which isn't difficult in a properly
designed installation) + ignition retard right there are very few downsides to nitrous oxide injection in a drag situation, as with the right
controllers you can manage injection timing to match how much power boost you require in the run to keep you on the limit of traction. You can also
use it very successfully with turbo charging and it can also be used very successfully in a normally aspirated motor and also with meth/water charge
cooling.
So none of the options are mutually exclusive - it's all a matter of getting your build and installation right.
If I were building a drag monster I would start with Nitrous and when I reached it's limits switch to Turbo + nitrous. The type are engine mods
needed are basically the same for both although turbo might need a lower CR than Nitrous if boost levels climb above 1.5 bar.
[Edited on 26/10/14 by Ivan]
As an after thought - if I were spending that much money I would add exhaust temperature probes to each exhaust tract and constantly monitor exhaust
gas temps to ensure that mixtures were spot on all the time.
[Edited on 26/10/14 by Ivan]
So the logical progression is NOS first then when you reach it's limits add turbo.
[Edited on 26/10/14 by Ivan]
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ian.stewart
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| posted on 26/10/14 at 03:32 PM |
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Methanol is also exceptionally corrosive to most of your fuel system, Go Nitrous if you want cheap power, use the right controllers its very good, and
quite safe as long as you follow the rules, Things like fuel filters are essential and checked regularly,
Something different, Very different..............
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metro6r4
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| posted on 26/10/14 at 07:10 PM |
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the current development plan of the car is as follows
1)install the new engine and run with a modest state of tune while future proofing were ever possible
2) rectify any issues with the current setup
3) a few aero upgrades and a few cosmetic changes
4) turbo charging the engine to running a highly modified set up with low compression pistons and all supporting modifications
should we not reach our target of 10 seconds or less without nitrous then I will add it as a final stage but I do not want to unless absolutely
necessary as the owner of the garage I rent doesn't want it in there unless absolutely necessary.I can install it but I will have to pay more
rent as it will put the insurance up quite a bit. I am hopping with the current round of upgrades that I can seriously reduce the times enough that I
won't need it with the turbo upgrade anyway.
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froggy
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| posted on 26/10/14 at 07:48 PM |
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What does it run the 1/4 mile now ?
[IMG]http://i144.photobucket.com/albums/r187/froggy_0[IMG]
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metro6r4
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| posted on 26/10/14 at 08:22 PM |
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the best time it ran with the old Yamaha r1 engine in was a mid 12 but that was with a big wing and down on power
the old engine never did run great. Since then I have had blanking plates made to lose the rear wing as the wing stays supported the rear clamshell
and moved on to a decent set of slicks we think with the rear wing removed it would have lost at least half a second of my times had I not blown it up
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froggy
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| posted on 26/10/14 at 08:31 PM |
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I don't see a wing costing much time over a 1/4 mile as the bike engined stuff is all about the first 660 ft given their low terminal speeds .
[IMG]http://i144.photobucket.com/albums/r187/froggy_0[IMG]
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metro6r4
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| posted on 26/10/14 at 09:01 PM |
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it wasn't a small one and you could feel the drag at speed it may be less I don't know but it was certainly slowing the car down
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froggy
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| posted on 26/10/14 at 09:12 PM |
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Pretty normal for a bike engine to feel like that as 150hp soon runs out of steam acceleration wise at 80-90 mph in relation to how it gets to 80 mph
[IMG]http://i144.photobucket.com/albums/r187/froggy_0[IMG]
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metro6r4
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| posted on 26/10/14 at 09:23 PM |
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it will be interesting to see what it handles like without the wing I have a smaller spare should it be allmover the place.i doubt the old engine was
even making 120hp to be honest I think its going to be an animal with the near 200hp it should have when all the work is done and the new engines
ready to rock
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