Something else about stalling: lots of carbureted and early fuel injected cars had a hydraulic damper to keep the throttle from slamming all the way closed. You might make up a bracket and install one of those. 2nd gen RX7's have a nice adjustable one and the bracket screws to the side of the throttle body, greatly simplifying making new bracketry. It looks like this:
Curmudgeon wrote: Something else about stalling: lots of carbureted and early fuel injected cars had a hydraulic damper to keep the throttle from slamming all the way closed. You might make up a bracket and install one of those. 2nd gen RX7's have a nice adjustable one and the bracket screws to the side of the throttle body, greatly simplifying making new bracketry. It looks like this:
The Strombergs have a bypass valve that opens up under decel and dumps air straight from the air cleaner to the intake manifold, bypassing the butterfly. I was told they were for emissions reasons and I like the popping that results from disconnecting them, but maybe I should reconnect the things.
Looking at the pictures from the first autocross, the Pink Panther has a little too much body roll so I am installing a front sway bar. And before anybody suggests that it will just understeer, remember that I have an adjustable rear sway bar and can change the motion ratio of the rocker suspension and stiffen it up considerably. I used some aluminum stock and angle pieces to make mounts and brackets to hold a stock MGB-GT front sway bar to the new frame and suspension.
And I replaced the soft rubber bushings with aluminum ones:
Here it is installed on the car:
And I made the drop links out of .75" square tube with nuts welded on to hold the heim joints:
There is a lot more detail on my blog
Speaking of motorcycle shocks, adjustable motion ratios, etc., how is all that working out for you? I've been tempted to explore that direction, but figured my car was probably to heavy since the only successful executions I had seen were locosts. But your car is heavier than mine, so if it's working, I might re-open that possibility.
I'd like to hear more about it as well. I dont remember seeing much abOut setting it up in the blog but I may have missed it.
DILYSI Dave wrote: Speaking of motorcycle shocks, adjustable motion ratios, etc., how is all that working out for you? I've been tempted to explore that direction, but figured my car was probably to heavy since the only successful executions I had seen were locosts. But your car is heavier than mine, so if it's working, I might re-open that possibility.
So far the shocks have been perfect, but I have only 4 autocross runs to go by. We run on a very bumpy surface and the damping seems to be very, very good. The car didn't crash over bumps, bottom out or act weird. I'll know more as the season goes on.
I'm running motorcycle shocks on the MG project (I say running but more acurately should say parking). I've not had the pleasure to drive it, however It will weigh in the 1500lb range with driver so I'm on the bubble for 4x MC rear wheel load area. that said they may work ok for you Civic Dave as you probably will be installing them with a MR that is low enough that their spring rate remains high. Mine are installed at ~2.5hz (E/Dmod car) so I'm using a wheel rate of ~400lbs out of a shock that has a spring rate of 800lbs. I get ~3" total travel out of the suspension. Things to remember when using MC shocks. Unmodified they are short stroke (~2" for most), High spring rate (600-800lbs), and have lots of pre-load (My R1 shocks have ~150lbs minimum pre-load which works for me as I need to maximize shock travel for my desired spring rate). If you can install them at a MR that works for your application then they are pretty well damped shocks that a VERY cheap and quite adjustable. My front shocks are CBR600F4i shocks and even have remote resivoirs. Dave whats your wheel rate target (in HZ) and what are your front and rear corner weights? That information can tell you if they will be suitable.
In reply to nocones:
Sorry about the tangent, and perhaps a separate thread is needed. BUT- that's some great info there, nocones. Are there any web pages that outline MC shocks, stroke, and stock dampening rate?
edit- there is a webpage that does calculate geometry rates, BTW. Not sure what specific infomation is needed, and if the calculations will produce that or not....
I've been toying with the idea of a 2000lb car with inexpensive shocks, 500-700lb spring rates in the front, 300-500 lb in the back. Heavier than a Locost, lighter than the Pink Panther.
I'd love to make said car a GRM challenge car that's capable of winning at a national Solo event.... 
alfadriver wrote: In reply to nocones: Sorry about the tangent, and perhaps a separate thread is needed. BUT- that's some great info there, nocones. Are there any web pages that outline MC shocks, stroke, and stock dampening rate? edit- there is a webpage that does calculate geometry rates, BTW. Not sure what specific infomation is needed, and if the calculations will produce that or not.... I've been toying with the idea of a 2000lb car with inexpensive shocks, 500-700lb spring rates in the front, 300-500 lb in the back. Heavier than a Locost, lighter than the Pink Panther. I'd love to make said car a GRM challenge car that's capable of winning at a national Solo event....
Let's just say "me too" except replace this: "I'd love to make said car a GRM challenge car that's capable of winning at a national Solo event...." with this: "I'd love to make said car a GRM challenge car that's capable of driving to work every once in a while and running tens pretty much at will...."
I broke the MC shock stuff out to a new thread. Motorcycle shock discussion
I think I solved a laundry list of problems today: 1.Spinning inside tire-Took the diff to Asperline on Monday and they found the LSD clutch discs to be worn out. Discs were replaced and shimmed for minimum slippage. 2.Engine running a little too warm-Took rad to shop to get converted to dual pass style rad. Now coolant is forced to go across the cooling surface instead of taking a shortcut down side tank. 3.Power loss-Installed Aeromotive fuel pressure regulator and changed oil in carb from straight 30 to synthetic ATF so the dampers can open more quickly-seems to have worked, throttle response is improved. 4.Coolant overflow-Purchased Moroso Coolant overflow resevoir from www.fasttoys.net (also got pressure regulator from them). 5.Potential understeer from front sway bar installation-adding front sway bar stiffened front suspension frequency from 2.19 Hz to 2.44 Hz. I changed the rear motion ratio from 1.42:1 to 1.37:1, and this changed the rear suspension frequency from 2.53 Hz to 2.65 Hz. I still have the rear sway bar to adjust balance. 6.Unknown timing-My previous mod to the timing marks was tested today. Using a timing light, I was able to determine that the car has 10 degrees initial advance and it's maxed out to 40 degrees by 3000 rpm-coincidently, this is exactly what the guys on the Jag forum say that my engine should have for performance.
If you are running this weekend, it's better off that you made it good, it's the end of the world you know ;)
I may need an oil cooler but have no good place to mount one, so I built these radiator clamps out of steel and will use them as templates to get some aluminum ones built. They clamp onto the rad and hold the cooler behind the lower spoiler opening.
I had a very bumpy abandoned runway to test out my changes the other day. The new front sway bar and changes to the rear motion ratio seem to have done exactly what was expected-there is much less body roll and quicker reacting handling but it's also less forgiving. I went from full soft to full hard on high speed compression and the car felt most controlled somewhere in the middle. I tried stiffening low speed compression on the back only and the car went from planted to tail happy pretty quickly. Full stiff on the rebound seemed to reduce traction but adjusting to the middle felt right. I suspect the whole set-up is just a little too stiff for the very bumpy surface but I'm pretty optimistic for Nationals. I am concerned about the lack of traction off the line and under hard braking. The car has 93% anti-squat and I can raise or lower that with an adjustment of the top bars on the 4 link, I think I want to try lowering the AS number to improve braking performance. I also have an oil leak and the back of the rear spoiler and expansion chamber of the diffuser seem to have sucked up every drop of it-a good sign that the aero is working, I think. And it looks like I will have to vacuum out the interior of the car after every event because it fills up with small rocks kicked up by the slicks. Here are a couple of short videos, pardon the audio, I forgot to plug in a mic: acceleration test http://www.youtube.com/watch?v=9Yqpc0-8k8U slalom test http://www.youtube.com/watch?v=SZPos62DFw0
Yeah, I can see that testing on a surface so different from the one you're trying to tune for can be a pain. Good thing you've got the knowledge & experience to fill in the blanks. Still loving the car, good luck! I wish you'd been able to take it to Lincoln, I'm curious about how it would have done..
friedgreencorrado wrote: Yeah, I can see that testing on a surface so different from the one you're trying to tune for can be a pain. Good thing you've got the knowledge & experience to fill in the blanks. Still loving the car, good luck! I wish you'd been able to take it to Lincoln, I'm curious about how it would have done..
I'll be there at the end of August, is that good enough? But seriously, the car is fresh out of the fab shop and almost nothing is normal is standard so there is much to go wrong. If, for example, my first event had been Lincoln, I would have made 2 runs and would have had to pack up and go home because of the problems that cropped up. I prefer to get the bugs worked out locally so I am sort of ready for the big show in Lincoln. I am happy to say that the stuff I built was all awesome, only the engine was a problem-no suprise, it's been sitting in a shed since around 1980.
I needed to fill the gap between the floor and the diffuser so I took a sheet of aluminum and made room for the lower bars and diff to poke through and put it on. Here is the before:
And after:
That's tremendously arousing.
Remember when testing on various surfaces to log the settings and reactions. It could help you in the future. A buddy keeps all of his notes on a tablet PC and will set up his car when he gets to the event for the conditions.
John Brown wrote: Remember when testing on various surfaces to log the settings and reactions. It could help you in the future. A buddy keeps all of his notes on a tablet PC and will set up his car when he gets to the event for the conditions.
Yes, I printed up some data sheets to record everything but I'm finding it very difficult to have time to write verything down and get data like tire temps and such. I have to train my wife how to take tire temps and adjust shocks.
The Pink Panther's second event went much better than the first. The new front sway bar, rear suspension adjustment and undertray all worked very well plus the car didn't leak any oil or coolant this time. Perhaps I let the car idle for too long because it ran a little warm on my last run and it tends to stall under braking when the coolant gets above 200 degrees. I actually had time to fiddle with shock settings and landed up being full soft on high speed compression, a few clicks harder on low speed compression and around the middle of rebound damping. I think I can improve turn-in with giving the car a little more toe-out and I am going to adjust the rear 4-link for better braking but otherwise I am thrilled with the handling, which I found to be very much like an S2000. The engine still isn't making the power it made on the dyno so I must find those lost ponies somewhere. Here is 4 really shaky videos of my runs and one really good one, all with data included: run 1 hit cones http://www.youtube.com/watch?v=8kpZxeVvSDM run 2 hit cones http://www.youtube.com/watch?v=Ji-YT_F0VI0 run 3 clean http://www.youtube.com/watch?v=52EOqTlfAlg run 4 stalled on course http://www.youtube.com/watch?v=lONJQIWQTp8 best run with different camera http://www.youtube.com/watch?v=FKU46c_HFqI
At the last autocross, I was very disappointed with the power of the car. The dyno said 290 hp and 288 ft/lbs but my butt dyno said it was a lot less than that. I even called the dyno guy and questioned the accuracy of the equipment. Well, anybody familiar with Stromberg or SU carbs will look at the pictures below and know immediately what the problem was-a torn diaphram. The diaphram raises and lowers a sleeve inside the carb, allowing more or less air in. This diaphram was ripped and so the sleeve wouldn't allow any more than a trickle of air into the 3 cylinders fed by this carb.
I also discovered a big ignition timing problem. I had purchased a new cap and rotor from a "Top Seller" on E-Bay and I should have known the quality of the parts was poor when the rotor just snapped in half when I tried to install it. Well, the cap recently failed as well so I went back to the original Lucas distributor cap. I'm guessing that the knock-off cap and factory cap didn't share the exact orientation on the distributor because the timing was suddenly 20 degrees too advanced. This now makes me question the quality of the thermostats I purchased from the same seller because even with the oil cooler hooked up, the coolant temperature is too high.
Yeh, if this season goes well, I'm going to try to fit EFI over next winter.
I cant get enough of the pink panther. sooo many good things going on in this thread. Its inspiring to those of us who are just getting their feet wet with metal fab and prepping a car for the track.
Tim et al - please find a way to get this car into the mag...even just IHROTM or something.
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