Project; Whizzy Pop Slingshot

[Gixer1460]

8 hours ago, wombat258 said:

I run 9:1 on 11psi, with 98RON fuel. Target AFR is 11.9 at full boost. Higher boost requires lower AFR. Timing should not be over 28 degrees. 

Generally agree with that apart from 'higher boost requires lower AFR' It doesn't and in fact it can make the situation worse. You are pumping fuel in hoping it will cool the cylinder and prevent detonation but most will be ejected and end up burning in the turbo which in extreme cases take all the tips / edges off the turbine wheel. The only safe way to run big boost is either lower compression or better fuel - end of! My bike got mapped to 1 bar using regular 98 unleaded but to go higher we used 120 octane leaded race fuel - ign. timing was unchanged, CR stayed 9.5:1, AFR remained stable and fueling adjusted against boost via MAP sensor but no detonation. It hurts paying for that fuel, but power costs and how much can you afford?

[Danm54]

Perfect, I'll give the valves a clean up and a check over but they are seating right.

 

The wastegate has been like that since it came back from John, I've never touched it assuming that it was set correctly.

Didn't pay attention to boost pressure on the dyno day either, the boost gauge on the bike always resets itself at about 0.6 bar so you never see the peak boost pressure, just thought it was fucked and needed replacing.

 

What sort of afr range so I be aiming for then, is 12.1 ok for higher throttle openings and rpm?

 

Thanks

[wombat258]

I respect your opinion but it is well documented that lower AFR reduces octane demand of turbocharged engines. It does not overheat the turbine. I have raced at 11.9 AFR with no det or overheating and the engine  and turbo look great. My race car has serious aero and fully loads the engine on race tracks for extended times. But hey, if you believe in your theory stick with it. If you want to go serious boost though, or have an inefficient turbo with no intercooler, you will have to use high octane race fuel. I am happy at 270hp so no need for high boost and the headaches that go with it.

 

[Gixer1460]

1 hour ago, Danm54 said:

What sort of afr range so I be aiming for then, is 12.1 ok for higher throttle openings and rpm?

For me with the level of boost you are aiming, at it will be sufficient with another point down if things get a bit marginal, some may disagree.

[Gixer1460]

1 hour ago, wombat258 said:

I respect your opinion but it is well documented that lower AFR reduces octane demand of turbocharged engines. It does not overheat the turbine. I have raced at 11.9 AFR with no det or overheating and the engine  and turbo look great. My race car has serious aero and fully loads the engine on race tracks for extended times. But hey, if you believe in your theory stick with it. If you want to go serious boost though, or have an inefficient turbo with no intercooler, you will have to use high octane race fuel. I am happy at 270hp so no need for high boost and the headaches that go with it.

 

Its not theory - its tested 369hp with some to go - it only stopped as the undersized injectors max'd out! You are, lower CR, lower boost, lower octane, lower lambda and lower power. If it suits your application then go with it - i'm not knocking it but if a cut needs stitches, a plaster ain't going to be sufficient!

Mine was built to make power, turbo flow is good for potential 450hp , 8 injectors (now with 75% more flow) and an intercooler. If increased AFR's are the cure, why use E85 or Methanol - both have considerably less power potential than petrol even when run rich - its because the octane rating / anti det. properties knock petrol out of the field and you can run as much boost as the engine can tolerate to make power.

[Danm54]

Headers version 3, going to drop 2 & 3 into the v, one either side.

Thoughts?

[Gixer1460]

Not a fan! Lot of pipe will lose heat energy = less to spin turbo. Look like std. dia. pipe? Smaller than usual helps gas speed. You asked! LOL

[Danm54]

Haha, didn't think it looked right myself which is why I stopped and asked.

 

Should they collect sooner? The normal draw through headers have a lot of pipework before they collect so not sure how much difference it actually makes.

[Duckndive]

5 hours ago, Danm54 said:

Haha, didn't think it looked right myself which is why I stopped and asked.

 

Should they collect sooner? The normal draw through headers have a lot of pipework before they collect so not sure how much difference it actually makes.

The Early Bottom exit Mr Turbo headers "As Pic" were quite short compared to the later side exit version's....

 

[Danm54]

Thats similar to what came off but I need to fit a rad in front so have to keep the 4 pipes flat to the frame.

 

When I started I was just going to pull the 2 inner pipes back but that left a long pipe straight down after it.

 

Maybe I need to alter the up pipe so it doesn't drop as low, could collect them higher then take it sideways earlier.

[Danm54]

Take 2 

[Danm54]

More header bits have arrived

 

 

And some damn expensive pistons

 

 

Stacked out with work again so these will have to wait until next week.

[Danm54]

Progress today

 

 

 

Cylinders 2 & 3 next.

 

Barrels and pistons are with Wards waiting to be bored.

Cylinder head has been checked for flatness on a CMM, its 5 microns out so I think its flat enough...

[Danm54]

Finished the headers, spooned one of them when I cleaned too much inside and broke through, sorted it ok but it could look nicer.

 

 

Got a full sized rad in with plenty of wheel clearance so should keep it cooler now

 

 

Made an adaptor up to get from the twin 38mm to the 51mm, wont go into the v-band but its good to hold it while its tacked. Got to move up yet so I've got some trimming to do

 

 

[Danm54]

So progress is slow as I've just started my own company, going to be tight on cash for a bit but may get some full days on the bike whilst work comes through.

 

So this afternoon was cc time

 

 

Need to dig out the calculations from last time then see where I stand on the comp ratio.

[Danm54]

Used the copper base gasket I had made a couple of years ago and with a 0.18" head gasket I'll come out with 9.14:1 comp ratio and 1.77mm squish.

[Danm54]

Little comparison between the new and old pistons, both MTC turbo. New ones have loads more meat on them.

 

[Danm54]

Got a mate to pop over and give me a hand on with the barrels, put the pistons in while they were on the bench then dropped the gudgeon pins and buttons in whilst holding the barrels up.

Tricky but fairly easy with 2 pairs of hands.

 

[Maggo]

Love the headers!

[Danm54]

Its arrived earlier than expected!

 

 

Can crack on and get the engine back together now.

[busa ash]

good luck with your new venture mate , and bikes coming along nicely 

[Danm54]

On Thursday, January 26, 2017 at 10:45 AM, busa ash said:

good luck with your new venture mate , and bikes coming along nicely 

 

Cheers Ash, getting enough work to get by with a few days off to play as well. Monday is looking like engine rebuild day!

[Fula28]

Good for you Dan, Allways a positive thing to hear going it alone and being your own boss it's tough but rewards can be huge in time.

[Fula28]

 Motors com No nicely too, Do you think you had boost spike during  Dyno time maybe.

Edited January 28, 2017 by Fula28

[Danm54]

Considering the bleed valve for the wastegate was wound fully in, its a possibility.

Had a couple of tight intake valve clearances and the MAP sensor went down during tuning with John so the engine didn't get an easy time.

 

Biggest problem at the minute is waiting for people to pay their bills but considering I'm only 3 weeks in and done a maximum 4 day week its looking good.