Milwaukee Midget

[wisdonm]

Have you re-thought fuel injection? Straighter inlet manifold runners and computer tune ability may give you enough of a power increase.

To lower the front end, just move the bottom spring perch to the bottom of the A-arm. Use longer grade 8 bolts and spacers until happy. Shortening the springs, with a cut off wheel, would be a more aero method.

Wrap the A-frames and springs with racers tape, if legal.

[Milwaukee Midget]

Have you re-thought fuel injection? Straighter inlet manifold runners and computer tune ability may give you enough of a power increase.

Everything is on the table at this point.

To lower the front end, just move the bottom spring perch to the bottom of the A-arm. Use longer grade 8 bolts and spacers until happy.

That's what I've already done - it would be sitting about an inch higher if I had left it stock.  Longer spacers and bolts - that's the next step, but I'll need to take care of my wheel well clearance issue before I drop it any further.

I did stop by Bob Bleeds shop - he was out, but I want him to take a look at the panel alignment, the wheel wells, and get his input on tightening up gaps and creating tire clearance.

[fordboy628]

Midget, Marcello:
You’re so close--only need about 10% more.
Some ideas in addition to what has been suggested above.

Aero
Since closing the grill and/or radiator seem to be against the rules, fit a radiator with exceedingly close fin spacing or maybe some damaged fins.  Close off any other internal flow paths from behind the grille except maybe a “cold” air duct inlet for the engine airbox.     Some of this has been done.   More attention will be devoted here.
Lower the car, maybe a bit of rake, too.   This has already been done, the max that was easily achieved.   More needs to be done.   MAY require shorter front tires to improve the rake . . . . .   Talking about lowering the front to the point where it's on the ground at launch, because of the high speed lift.
Tire pressures?    Probably should have been running the higher pressures all along . . . . .    Well, you learn as you go . . . . . .
Were the windows rolled up?    Yes.   Probably going to check if there is any lexan window deformation at speed.

Power
In the dyno session I seem to recall that you just chose the better of the inlet and exhaust configurations that were at hand.  Both of these may respond to refinement and tuning for the generally hotter conditions at Bonneville.   Undoubtedly true.   Have to get more experience with jetting the carb for the severe Density Altitude differences @ B'ville.   What are the inlet and exhaust tract geometries at present?    It's a non-standard combination for the engine's displacement, based on what is currently accepted as gospel for BMC's.   None of which I care about.   We made tuning choices based on dyno results . . . . .   Do they work together?    Yes and no, er, it's complicated.   I picked the inlet length for one peak torque rpm and the header primary length for another, slightly lower peak torque rpm.   I did this to flatten the torque curve and give a wider usable bhp curve.    Now that Midget has gotten a year with a bunch of good runs, and the car and concept have proven competitive, probably going to do a couple of things to raise the bhp output and narrow the useable power range.    One will be to tune the inlet and exhaust tracts to the rpm at top speed.   Probably narrow the working range from 2200/2000 rpm to 1700/1500 rpm.    With the close ratio gearbox he has, and the narrowed powerband, probably looking at a push start . . . . . .
Icewater intercooler?   Definitely, on both fuel and inlet air, if legal in GT.
Front end toe minimized.   At factory minimum now, probably going to try less.    
Slow down the water pump.  It’s probably cavitating at 8k anyway.    Already done.   His original setup, (and what most Spridget racers use), spun the water pump at 13,000+ rpm at 8000 crank rpm.   As I'm sure you will agree, that's crazy.   Back in the build diary are photos of the gilmer belt setup I designed and machined to fit this application.    It uses a 3/8 pitch toothed belt with a 15/28 under drive ratio for a .5375 w/pump to crankshaft speed.    At 8000 crank rpm, 4286 water pump rpm.    I wanted to get it a bit lower, but 32.96% of the original water pump rpm is way better.    It also uses a wider than needed water pump pulley, so that an additional accessory drive can be fitted.    Say, uhmm, a dry sump oil pump . . . . . . .

Interested Observer,

All great ideas, some/most of which have been partially used.

Going to come up with a strategy for reducing potential brake drag.   Also going to reduce trans/diff losses by going to lighter synthetic lubricants coupled with lowered fluid levels.

I am confident that the Grenade's output can be raised to about 103/105 bhp reliably.   Since the 1310cc F/Prod SCCA engines are making 106/114 bhp/litre (depending on whose dyno numbers you believe . . .) we might be able to achieve that level.   Since the 999cc has better breathing capability coupled with lower flow demand, we might even do slightly better.    I want to remain realistic though, no Nascar or F/1 budget here . . . . .

As always, thanks for your thoughts.
 
Back to Fordboy

[fordboy628]

Back to improvements

And keep the front (disc?) brakes -- just disable them.  That way you don't have to screw around with them every run.  (Street Roadsters all have lights and horns, bet a lot of them don't work.)  As easy as it is for you to get in and out of it, I don't think you'll be making short hops to the store.  At 123 MPH, the back brakes ought to work in a mile.

A think that a driver controlled "line-loc" to the front brakes only would keep the pads backed off the discs.  (If this is allowed . . .)  Being able to control it from the driver's seat allows 4 wheel braking to slow the car in that last mile.   I think it was Hurst that originally made them.    Just a 12 volt solenoid valve for a hydraulic circuit . . . . . .    They are still listed by Summit/Jegs/etc . . . . . .

 
Formerly Dragraceboy

[fordboy628]

How is it possible for this Corvette to be running in D/GT with this scoop and spoiler?   (photo in reply #13)

http://www.landracing.com/forum/index.php/topic,13087.msg231134.html#new

https://lh5.googleusercontent.com/-LYcaecSF8AU/UhT8vDIiNUI/AAAAAAAACRs/GWBUZEDjRus/w1239-h929-no/P1100005.JPG

Just asking.   Not trying to upset anyone.

Question Mark & the Mysterions

[Tman]

Yes, you can add springs to keep the pads off the disks. Tony/magoromic has discussed this in his threads

[wisdonm]

He's also got a double damned air dam.   

The standard answer in road racing would be "It's OK, it's a Corvette".

[Tman]

How is it possible for this Corvette to be running in D/GT with this scoop and spoiler?   (photo in reply #13)

http://www.landracing.com/forum/index.php/topic,13087.msg231134.html#new

https://lh5.googleusercontent.com/-LYcaecSF8AU/UhT8vDIiNUI/AAAAAAAACRs/GWBUZEDjRus/w1239-h929-no/P1100005.JPG

Just asking.   Not trying to upset anyone.

Question Mark & the Mysterions

"Air dams (4.CC.1) identical to factory optional equipment may be added"

[Stan Back]

But, but, but there's no need for front brakes on that car at the speed it's running.  Just internally disable them.  $0.00.

[lsrjunkie]

Great point Stan! I took the same advice from you on my car.

[Milwaukee Midget]

You can run any class you want with anything you want.  It's just that if you wind up in impound, and it doesn't meet the book, don't count on getting into the record book.

[Tman]

But, but, but there's no need for front brakes on that car at the speed it's running.  Just internally disable them.  $0.00.

I agree Stan.

[Milwaukee Midget]

Call me chicken, but I kinda like the idea of brakes. 

I'm thinking backdating to Bugeye drums and backing them way off.

[Dr Goggles]

If yr gonna get a monkey to drive it take out all the "over and above" safety equipment you can, sheesh our car just has backs,it makes the Colonel nervous ,I'm fine with it........

[Milwaukee Midget]

If yr gonna get a monkey to drive it take out all the "over and above" safety equipment you can, sheesh our car just has backs,it makes the Colonel nervous ,I'm fine with it........

It goes beyond stopping the car.  We put 400 miles on the Dodge dragging the Midget back and forth over 4 days.  The Dodge can stop on a dime, the Midget - not so much.  The easiest way to tow it I found was to keep a bit of brake on while in tow, which kept the rope from becoming slack and prevented me from slammin' into the tow vehicle.

Yeah, a longer tow rope, but the point is that in an emergency, it needs to stop as quickly as the tow vehicle.

A tow bar is questionable because the steering is severely limited and I don't think it would follow the tow vehicle well.

In the case of a tank, you're front is exposed, and it makes sense to keep the aero around the front tire clean.  Brakes on the front are of no aero concern with the Midget, and if I can keep 'em and be assured they aren't dragging, it's silly to get rid of them.

Yeah, I'm kinda stubborn on this one, but NASA used to send monkeys into space, and not all of them came back.  I want a better track record than that.