My setup - odd jet ratio - Friday night discussion

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DaviesDJ
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My setup - odd jet ratio - Friday night discussion

Post by DaviesDJ »

Hi guys, always enjoy a Friday evening discussion and thought I would get some opinions on my current gas setup in the Landy. I currently have a WON fixed hit wet system with DIY (working) bottle heater, 2x cross fires on a plate under my Eddie 600 carb. The nylon tube goes directly down from the bottle out of he floor along the chassis rail into he engine bat, the solenoids are mounted on the car studs with fuel and nos Y peice splitters. Total length of tube from nos solenoid to crossfire jets is about 6-9 inches including split. My fuel pump is a facet gold flow item- feedin mounted to the chassis rail below, there is a regulator- which is one of those cheap items with a dial from 1-5 on the face - I have it set to 4 but have not checked the pressure with a gauge properly- "regulator" is between the pump and Fuel T to NoS. currently running 200 jet now and 90 jet fuel, and wih pressure in he bottle (this time of year) at about 700-800 PSI I getting AFR of 10 (lowest possible). When pressure in the bottle is 900-960 the AFR creeps to 10.3 Ish. I wondered why my fuel jet is so small!! Am getting a good kick of power but need an expert really to assess if it feels like 100HP!! Think if I would go higher I will add a controller. But what jets has everybody else used with this type of pump!! Think my fuel regulator is pants! Is this jet ratio uncommon? I hear it should only be 2:1 in Hugh pressure injector pumps? Do you think I may have a problem with gas delivery?? No misfires or back fires - when I pull my foot off after a power run I get a cheeky little soft "pop pop" from the exhaust.

Any suggestions as to my funny mixture ratio, or is it actually not unusual with a facet pump (ignoring my regulator as I don't honk it works - eBay dial job)

Looking forward to opinions (esp perry) a love a Friday chat

Cheers

Dave


Spent so much on trial and error!

mgbv8
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Post by mgbv8 »

At that AFR I'm not surprised it feels soft. The pops in the exhaust is just excess fuel burning off.

Lets do the basics first!

What fuel pressure into the fuel solenoid?
Are these Wizards of Nos solenoids and how old are they?
Total length of nitrous line from bottle to solenoid?
What type and size of nitrous line?
What type and size of lines from solenoids to crossfires?

The jet ratio does have some basic rule of thumb stuff attached. Typically on a low pressure fuel system of say 5psi you would normally jet 1:1 nos to fuel.

With EFI pressures you start at 2:1 nos to fuel.

But these are only a guide as you will need to do some testing to arrive at your ideal jet ratio.

And theres plenty of testing that can be done to check fuel and nos flow without having to do running tests.

Lets have the answers from the above and we can start tracing any problems.

My initial thoughts would be blocked nitrous filter, maybe a fuel jet that has been bored out, blocked nitrous line or a kinked line, maybe even a faulty fitting that has crushed the end of the nitrous line.

Lots to talk about DJ ;)

Perry Stephenson

MGB GT + Rover V8

9.62 @ 137.37mph

Now looking for 8 seconds with a SBC engine

http://www.youtube.com/watch?v=nVscbPHgue0&list=UUqIlXfSAoiZ--GyG4tfRrjw



https://www.youtube.com/watch?v=eg3avnsNKrc&index=2&list=FLqIlXfSAoiZ--GyG4tfRrjw

DaviesDJ
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Post by DaviesDJ »

Cheers Perry mate! Will take som measurements today but unfortunately don't have a fuel pressure gauge to hand!! (I know!) but will source one and know I have needed to for ages! The solenoids are all less the 12 months old and have only seen 2 refils (11lb) and of course they are from WON!;-) the nitrous line is standard nylon SB 150 (5mm external I think??) and the fuel line is standard WON sb 150 nylon, will make the measurements today! And check for kinks. I was thinking about over tightening of the olives, I didn't put my back into it and I am hardly sly Stallone (as you know after meeting me;-)) but I did tighten the nitrous olives up quite tightly with a ring spanner, not thread stripping tight but firm you know. Could this have an effect?? I will get the measurements done today - and try and source a fuel gauge! I will post a pick of the setup also if this is helpful??
Cheers
DJ (quite like that "handle":-) - sad git I am!!)
Spent so much on trial and error!

DaviesDJ
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Post by DaviesDJ »

Spent so much on trial and error!

DaviesDJ
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Post by DaviesDJ »

Total distance of bottle to pulsoids (nylon tube) is approx 7.5 feet
Spent so much on trial and error!

mgbv8
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Post by mgbv8 »

7.5 feet of 5mm o/d nylon will choke the crap out of the nitrous flow. It should make a 100hp of flow if you havent nipped the olives down too hard.

If you have some decent digital scales and some nitrous in the bottle you can do a simple flow test. Weigh the bottle accurately. Get bottle to 850psi. Then disconnect the line from pulsoid to crossfire and do a full flow blast for 5 seconds only. Then weigh the bottle again and tell me how much ligther the bottle is??


Before you do this, pull the inlet fitting off the nitrous solenoid and see if the white filter is discoloured or blocked?

If you take off the nitrous lines and look in the end of the pipe you will be able to see if the inner bore has been made smaller by over tightening.

Perry Stephenson

MGB GT + Rover V8

9.62 @ 137.37mph

Now looking for 8 seconds with a SBC engine

http://www.youtube.com/watch?v=nVscbPHgue0&list=UUqIlXfSAoiZ--GyG4tfRrjw



https://www.youtube.com/watch?v=eg3avnsNKrc&index=2&list=FLqIlXfSAoiZ--GyG4tfRrjw

DaviesDJ
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Post by DaviesDJ »

I think I will first see with a gauge what my fuel pressure to the solenoid is. Then once that is a known factor I will re-route the black bottle to nos solenoid route. Think it takes quite a convoluted route! Have you ever set up a system using a facet gold flow pump?? In your experience what sort of ratio do you end up running?? NOS solenoid filter looks like new on inspection by the way. Ohh projects projects!! Stuart and I were welding the locost/westfeild chassis today! Going to run a High CR on that as a race engine- and it will have NOS but will ceramic coat the chambers to prevent detonation and run a separate NOS wet fuel supply of pure toluene. Have you seen this?

Cheers mate

DJ
Spent so much on trial and error!

mgbv8
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Post by mgbv8 »

If you have nylon line for fuel and nitrous you need to find a short route inside the car. The nylon is too easily damaged when run under the vehicle. If you weant to keep it all external then fit -3 braided for both.

I did used to run a 75 shot from the stock SU pump when the MG was a 3500.

Since then I've always run a separate fuel system for the nitrous fuel and always with a rotary pump. Mainly Holley red or blue now, but I did run a Carter pump for a few years.

At present I run the jets at 1:1 ratio but with 12psi of fuel pressure for the fuel solenoid which runs AFR around the mid 11's on a hard run. I can trim the AFR by tweaking a psi at a time when I'm testing.

Why would you want to run toluene? Is this for det suppression?
Wont a strong mix of toluene wash lubricant out of the bores?

If you are running stock compression ratio with the nitrous just take out 2 degree's of timing per 50 shot as a base line setup and keep the AFR 1-2 points richer until you have fine tuned the engine.

Use BP ultimate or V Power or even by a tin of Power Pour to mix with the fuel for racing if you are worried about detonation?

And for a 100 shot I would go one stage colder on the spark plugs for a trial.

Perry

Perry Stephenson

MGB GT + Rover V8

9.62 @ 137.37mph

Now looking for 8 seconds with a SBC engine

http://www.youtube.com/watch?v=nVscbPHgue0&list=UUqIlXfSAoiZ--GyG4tfRrjw



https://www.youtube.com/watch?v=eg3avnsNKrc&index=2&list=FLqIlXfSAoiZ--GyG4tfRrjw

DaviesDJ
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Post by DaviesDJ »

Already have cooler plugs on he Landy, and modified them to ease the likelihood of detonation, probarbly gone too far as I am only at just over 10:1. Toluene is a nic branched aromatic IMHO that is easy for me to get hold of does wash the bores due to is relative viscosity so I put a drop of 2 stroke oil in even mix when trailing it. This is not really for the Landy- I just use that to test it to check it works. My track/strip project (buildig) will run about 13.5:1 maybee more to flatten out the cam- I plan to use NOS on top of that hence the toluene - would use methanol but be stoichiometry of that means it has to be vey rich I Bellevue and obviously it's corrosive to standard lines and is an accumulative toxin, rely end is also nasty but not quite as bad;-). As you know mate I am a new we and if you think that is a daft idea do say- the Landy will see the strip come January but the 4.9 project will be ready in about a year (lol!!) - thought that toluene would just be a good way to add a nos blast while at very high Cr - although the dynamic CR probarbly wouldn't be that high. Thanks for the tips about the lines. Where are you based mate?? I am in brum now but do a lot of tinkering in northants.
Spent so much on trial and error!

mgbv8
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Post by mgbv8 »

DaviesDJ wrote:Already have cooler plugs on he Landy, and modified them to ease the likelihood of detonation, probarbly gone too far as I am only at just over 10:1. Toluene is a nic branched aromatic IMHO that is easy for me to get hold of does wash the bores due to is relative viscosity so I put a drop of 2 stroke oil in even mix when trailing it. This is not really for the Landy- I just use that to test it to check it works. My track/strip project (buildig) will run about 13.5:1 maybee more to flatten out the cam- I plan to use NOS on top of that hence the toluene - would use methanol but be stoichiometry of that means it has to be vey rich I Bellevue and obviously it's corrosive to standard lines and is an accumulative toxin, rely end is also nasty but not quite as bad;-). As you know mate I am a new we and if you think that is a daft idea do say- the Landy will see the strip come January but the 4.9 project will be ready in about a year (lol!!) - thought that toluene would just be a good way to add a nos blast while at very high Cr - although the dynamic CR probarbly wouldn't be that high. Thanks for the tips about the lines. Where are you based mate?? I am in brum now but do a lot of tinkering in northants.

I'm in Buckingham DJ. 5 mins from Silverstone.


Give us some engine specs for the landy and the project car DJ ??

Perry Stephenson

MGB GT + Rover V8

9.62 @ 137.37mph

Now looking for 8 seconds with a SBC engine

http://www.youtube.com/watch?v=nVscbPHgue0&list=UUqIlXfSAoiZ--GyG4tfRrjw



https://www.youtube.com/watch?v=eg3avnsNKrc&index=2&list=FLqIlXfSAoiZ--GyG4tfRrjw

DaviesDJ
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Post by DaviesDJ »

Bit further away the I thought! Never mind:-) th Landy is basically a TVR 500 short block- stage 3 heads skimmed down- composite gaskets - TVR 500 cam - advanced 2 degrees - Eddie performer manifold with 600
Carb and crossfire plate - mega jolt EDIS ignition- tubular 4-1 manifolds - AFR in y peice - all fully internally balanced - ARP stud kit - SD1 flywheel weight.mthe westfeild/locost will be (in progress) - cross bolted- 88mm stroke offset ground 4.6 crank knife edged - NASCAR 6 inch rods - ford modular flat tops- Buick 30" heads with 1.77 and 1.5 valves - ceramic coated valve backs (in progress) - 290-300 degree cam - roller rockers - chambers welded and coated- fabricated crossover manifold (undergoing coating) and either ITB or quad webers - pods for crossfire jets in the runners (welded in) - Buick tin CHG
What you reckon?
Spent so much on trial and error!

mgbv8
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Post by mgbv8 »

DaviesDJ wrote:Bit further away the I thought! Never mind:-) th Landy is basically a TVR 500 short block- stage 3 heads skimmed down- composite gaskets - TVR 500 cam - advanced 2 degrees - Eddie performer manifold with 600
Carb and crossfire plate - mega jolt EDIS ignition- tubular 4-1 manifolds - AFR in y peice - all fully internally balanced - ARP stud kit - SD1 flywheel weight.mthe westfeild/locost will be (in progress) - cross bolted- 88mm stroke offset ground 4.6 crank knife edged - NASCAR 6 inch rods - ford modular flat tops- Buick 30" heads with 1.77 and 1.5 valves - ceramic coated valve backs (in progress) - 290-300 degree cam - roller rockers - chambers welded and coated- fabricated crossover manifold (undergoing coating) and either ITB or quad webers - pods for crossfire jets in the runners (welded in) - Buick tin CHG
What you reckon?



What is the CR of the Landy engine?

With that basic spec in a Westfiled I cant see why you would want nitrous unless you will have some serious tyres with serious traction because its going to blow the rear tyres off all day long mate.
We have a westy that comes to the Pod now and then. When he eventually got the tyres and suspension sorted he pulled a big wheelie and broke his front suspension as he landed. So wheelie bars need to be on your list I think.

Perry

Perry Stephenson

MGB GT + Rover V8

9.62 @ 137.37mph

Now looking for 8 seconds with a SBC engine

http://www.youtube.com/watch?v=nVscbPHgue0&list=UUqIlXfSAoiZ--GyG4tfRrjw



https://www.youtube.com/watch?v=eg3avnsNKrc&index=2&list=FLqIlXfSAoiZ--GyG4tfRrjw

DaviesDJ
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Post by DaviesDJ »

You have no idea how big the smile is on my face:-)
It's a little heavier then a weary as it has steel panels and 17 inch wheels and I will put high profiles on.
CR in the Landy is about 10-10.2-1 approx
Spent so much on trial and error!

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