10 5's velobike

[mark105]

nah i was going to run suck through. would have to figure out fuel pumps and so on if i was to go blow through. plus from what i have read superchargers love methanol through them and it keeps them cold. although it should stay pretty cool as it will be at the front of the bike anyways.

ignition will be the fun part with running meth will have to figure out how to advance up the timing.

[Steelies]

cool. PUN

do you need any oil or some such in the fuel mix or ais the SC happy chomping down straight alcohol?

[Rookie]

Na SCs just love meth, ala blown bent 8 spec.

[Steelies]

nice. makes me think of the one time you try lubing your skateboard bearings with CRC

[mark105]

super charger has its own separate sumps for oiling its self so it can just chomp down on straight burnable stuffs and loves it.

[Toucan]

Mean

[Yowzer]

Well this looks interesting

[KIRK]

make sure you get a Gilmour girls belt

[Vintage Grumble]

If you need a toothed belt cut, i'm your man. We got shit loads of them and a cuttering machine here.

[Rookie]

As in cut to length? am registering interest...

[Vintage Grumble]

Well no, they come is set lengths, and we cut the width, they are sold by the MM. I have a list of what we stock somewhere, will try find it if anyones interested. Mind you, I think his pulley is multi-V, which we dont do.

[RUNAMUCK]

I'm feeing happy in my pants! (Superchargers have that effect on me)

I'm unsure how well the seals in the charger would handle Methanol. But if you put "Meth" into google images this is how happy running it can make you;

You're going to see that face looking back at you in the mirror every time you open the throttle.

On a more serious note though, I'll dig out the formumla for calcing your boost soon.

And I'd stick with the multi rib belt to drive it. They're very effective. Maybe run BD tensioner to tension the belt. (Durotorquw stz)

[RUNAMUCK]

OKay Fizz,

The number work like this.

Take your desired boost figure. (Lets say 14.7psi)

You take your boost number, and add it to atmospheric pressure. So 14.7+14.7=29.4. Devide that by Atmospheric pressure =2 this gives you your boost ratio. Then take the max amount of air your engine will consume. So 300cc, divided by 2 (four cycle engine) gives us 150cc. Get a redline of say 5000, 5000x150= (I don't have a calcuator here atm)

Multiply that figure by the boost ratio, at that give you the amount of air required at 5000 to make 14.7psi. Which is double cos in this case your boost ratio is 2. Then take your air volume @ your PSI, and devide it by your blower displacement. 300cc then you can work out whata speed your blower need to be doing to provide enough air to make that boost @5000 engine revs.

Since your blowe pumps 200% of what your engine can breathe, you'd get one atmosphere at 1:1 ratio. BUt the formula would also work if you decided that you only wanted to run 10psi. Remember that roots blowers start to make heat when the boost gets right up. (It's more the action of compressing the air that does it, moreso than the actual speed of the blower.

We also don't know how effecient your blower is. Tne toyota blowers never seem to produce real world boost numbers as hig as the drive ration should mathamatically generate. So fuck knows how good the AMR chargers are. Another school of thought I read somewhere was that it's better to drive a small blower faster, than a big blower slower. As at low speed the rotors have more time for air to leak past the rotors. BUt I reckon thats horseshit. Especially with new style superchargers which run tighter tolerances. The only other drawback with a bigger blower, on a smaller engine is the increased parasitic losses. But the gains in tourque far far far far outweigh those.

If my above raamblings are hard to follow, I stole the formula from here http://datsun1200.com/modules/newbb/viewtopic.php?topic_id=9997&forum=1&post_id=35090#forumpost35090

So you can mull over it in it's complete entirity.

Best you upgraade your valve springs too. With a bar of boost up it's gunga, the inlet valve will be wating to float sooner and easier than they already do.

[Seedy Al]

I love science

[mark105]

so this is what i am thinking. i am also using this to jot down notes.

8+14.7 = 22.7

22.7/14.7 = 1.54

300cc/2 = 150cc

3500x150 = 525000

525000*1.54 = 808500

808500/300 = 2695

2695/3500 = 0.77

so by my calcs i need to be 0.77 under driven to make 8psi of boost 3500rpm, i dont rev my bike much more than 3500-4000 rpm at current and i want to be making 8psi at those rpms. should make it scary enough i think. blower is on its way, mock up pics this weekend.

also mr Kirk did you get that sthil?

[RUNAMUCK]

Those numbers look pretty right to me.

The only thing that might fuck them up would be if your blower isn't very effecient. (You'll see less boost) Or, your engine is a bit asmatic and the boost will finish up being higher.

I've actually been thinking about your build all weekend. (I had today off too) When you're tuning it, it might pay to run a muffler so you can hear any pinging/detonation before it destroys the engine. Since you aren't running monster RPMS, it probably wont benifit from fucking with the advance too much, But likewise, since you're only increasing the torque, you might need to up the final drive ratio a bit to up the top speed. (Or were you just hoping for more mid range?)

Much over 8psi, you should seriously consider running methanol. (Because you can) Just increase the size of your jet by 40%.

[mark105]

it is defiantly geared fast enough. i just want to get there much faster with the short straights of the velodrome. methanol is def on the cards. which by the way where is the easiest place to get meth from? i actually have no idea. i will build a longer exhaust as i do plan to put the wideband on it for initial tuning so i can at least get it close with out riding load on the engine and just make a clamp on style muffler as once it is tuned its coming off for sure.

[RUNAMUCK]

I wouldn't know where to get it up there, but maybe some speedway guys might know? I think you can get it in 20tlr lots, but if you gotta buy a 209, maybe find a racer and get them to sell you 20 litres? PLus it absolutley must be stored in an airtight container. Shit is hygroscopic as fuck, and turns to shit if the air gets to it. (but you'd already know all that I would expect)

I also wouldn't know what stoich is for methanol either. Long term, a tuned length pipe for max torque would be awes too.

[Testament]

stoich for meth is about 6:1 but you can run as rich as 4:1

[UTERUS]

I have some mystery meth sitting on the shelf, seems like a good idea to run my tru test on it?

It's been there for like a year in a plastic container, should i worry about water or just slam it in and hope for burnouts.