Milwaukee Midget

[crew chief]

mr and mrs crew chief send a heartfelt congratulations on a job well done!
That must be the most radical 4 cylinder of all time! Next stop the dyno room.

[Moxnix]

M. Midget, in another life, is a reverb and twang specialist, and can be both heard and seen herein:

http://www.youtube.com/watch?v=ySH_DFygyvM

The guy in the hat. 

A true "son of the cheese" up in WI, and a racer.  Can't beat that.

[Elmo Rodge]

Cool.   It's not a splendid afternoon at the "White Goose Bar" but it'll have to do.  Wayno

[Milwaukee Midget]

Cool.   It's not a splendid afternoon at the "White Goose Bar" but it'll have to do.  Wayno

Well, the steel player left - they always do . . . they ALWAYS do - and we're looking for a harp player. 

[Elmo Rodge]

Cool.   It's not a splendid afternoon at the "White Goose Bar" but it'll have to do.  Wayno

Well, the steel player left - they always do . . . they ALWAYS do - and we're looking for a harp player. 

I'll keep my eyes (ears) open.  Wayno

[desotoman]

91.913 - in 3rd gear - ran out of track. 

Way to go Chris. Congratulations on your accomplishment.

Tom G.

[Milwaukee Midget]

Tom, Max, Frank - everyone - thanks.  It's turning into a better year than last.

Here's what's up.  I've booked 4 hours of dyno time out in Waukesha for the 19th.  They've got a Mustang chassis dyno that I doubt will be threatened in any way by the tire torturing torque of the Midget, but I dare say earplugs might be in order. 

I'm trying to put together the most efficient plan for the time.  I've read about it, but I've never done this before.  Many of you have, and I've got a few questions - some I suspect I'll have to answer myself.

So once again, I stand before the brain trust that is the Landracing.com forum, hat in hand.

What I'd like to do is spill out my plan right here, and if any of you think you've got a better approach or a comment, please post.

We'll be using an O2 sensor in the pipe.  I'll be able to log knock with the XDI software on board.

I want to try 2 pulls with my current timing - maybe more if the numbers are wildly different.
 
First off, I've only got two passes on the break-in oil at Maxton, plus a trip around the pits at Great Lakes Dragaway, and a couple of aborted passes up and down the alley in back of the house.  Should I change it out at this point, or no?

I want to start with the advance curve I just ran at Maxton.  I plan on checking the plugs and valve lash before I head out - optimize both, but no other tuning until I get there.

After that, I want to slowly advance the timing, right up to the point of knock, then dial it back a tick and turn on the knock retard circuit in the software.  I'm thinking that should act as a safety valve, but I need to run it under load in order to set the threshold.  I'm thinking I'll have 5 or 6 pulls at that point. 

After the ignition is set, I intend to pull the carb and change out the venturis to a slightly smaller set (38's to 36's), and see if that helps on the bottom end without hurting anything upstairs.  I'll be watching the analyzer in particular at this point, and comparing graphs.  This would be the last thing I'll want to do for the day.  The bottom end is not critical for Bonneville, but I'm planning on heading to Wilmington next April, and if I can spend less time launching, I can spend more time making speed. 

I'll have to hustle to get that much done in 4 hours, which includes the set-up time.  I don't think it's unreasonable, but do any of you think I'm over reaching?  Am I missing something?

The goals are -

Maximize the advance curve

Determine if my mixture is on, and if not, which direction I should be going with it.  If it's lean, it might end the session early, but right now, it smells rich.  Tweaking a Weber is more a matter of changing out parts than fiddling with screws.  I'm looking for numbers from the sniffer that will direct me to what I'll need at 4200 feet.

Eventually, I'll plot my shift points.

I'm thinking if I can get the info together on the 19th, I can make the changes this winter to the carb, and retest next spring to confirm.

Is there a better approach?  I'm all ears on this one.  I'm trying to keep the goals attainable, and the information reliable.

Thanks, all.

Chris

[Cajun Kid]

Chris, 4 hours should be enough time to make your pulls,,, make sure you have a fan on the radiator and if the dyno guy has a second fan for the engine thay would help to cool as well.

As to the Break in Oil,,, what kind did you use ?  We use Joe Gibbs Break in Oil and we do an oil and filter change after our initial dyno pulls (1 heat cycle, 1 mild pull and about 4 to 6 full pulls)  we never race on the break in oil,,, Based upon the time you have on your engine,,, I would say it would be good to go ahead and change oil and filter before the dyno runs.

I assume you will do dyno pulls in 3rd gear ? (not sure about your rear gear ratio)

Good plan and good luck.

Charles

[Milwaukee Midget]

Thanks for that, Charles.  Don't recall the oil brand, but it was recommended by my machine guy.  If I don't know, it's probably best to change it out. 

4:22's in the diff.

[Cajun Kid]

You should be able to make a 4th gear pull with that Ratio and get good data.

Yes, I would change the oil.   Advance timing 2 degrees after first pull and see how that works, then adjust 2 more. at first instance of knock, abort and back down a degree.  Make sure to cool engine between runs.

Charles

[Kiwi Paul]

What Charles said. Make sure you cycle the engine so that you start your pulls at the same engine/ambient temp. Do you have another set of eyes/ears you can trust to help? I always like to watch the open engine bay during chassis pulls, while the owner/driver is in the car. It`s been a while tho..

[Peter Jack]

All good advise, including your own. You're well ahead of the curve in that you've already developed a well organized plan. The only suggestion I have is that if you have time for a couple more pulls don't be afraid to try something else just to help give you direction. The dyno tends to know the truth! The only other suggestion is that if anything seems amiss at any point don't go on until you know things are okay. The sudden loud noises or stoppages tend to be expensive!

Be aware that if you've never been exposed before the first pull is scary. Good luck and have fun.

Pete

[Captthundarr]

Chris, sounds like you have a handle on it. Maybe if you have a coulpe of spare hands a video of one of the the pulls would be neat to see. With sound good luck.

Frank

[Tman]

Chris, I still have those latches for you.

[JoshH]

"I want to slowly advance the timing, right up to the point of knock, then dial it back a tick and turn on the knock retard circuit in the software."

Are you just going to listen for audible knock? If so, you might not catch when it really starts. You might want to ask the dyno guys if they have knock detection tools, like this:
http://store.apexspeedtech.com/phormula-ks-pro-knock-analyser

Knock sensor can be pretty tricky to set up and its not for the faint of heart, because you have to induce knock to do it. Be careful.