LocostUSA.com

True. In Tong's case, every tube that crosses the car left-to-right has a center-line mark put there during the construction phase, and checked periodically to make sure it remained accurate. Should be pretty easy to transfer that to a set of toe bars. Doing it 'after the fact', I would probably attempt to recreate the center-line on the underside of the floor.

Thank you!



I used a coleman racing rack. they are now offering custom length racks for not much more than their normal racks and even aluminum housings - great options for a locost build

I had a the car out for a heavy weekend of Evo autocross school on saturday & a PCA Autox on Sunday in Packwood - car saw 40+ runs and it ran really well. only a few minor hiccups - my incomplete starter wire from the starter button to the starter came out of its electrical tape... and my exhaust turndown fell off at some point from its few tack welds and got driven over.

Trailer worked great and after fiddling with some tire pressures and where to load the car on the trailer my little wagon towed the car without a hitch up and back

All loaded up


unloaded up at packwood


my little video camera didn't record my runs for some reason so I don't have any on-course video to show off

car is a blast to drive, still a handful to get used to but that many runs really helped build my confidence in the car and get me to know how to drive it a bit better.

I'm also still trying to figure out how to use the insanely clunky racepak software. apparently i'm not the only one as everyone on the racepak forums loves the dash and hates the software. it's maddening in its complexity



this is a trace of lateral G (green), RPM (red), & Throttle position (blue) for one of the runs. I was able to find a few spots where I was being a lot lighter on the throttle than I should have been, a spot where I up-shifted ~1200 RPMs short and also that I inadvertantly had my redline set lower than I thought! It's pretty cool to be able to have the GPS course laid out and then to look at the less-thought about items like what my coolant temps looked like.

the best thing is that it shows with my ugly over-driving it's good for at least 1.7 Gs in a corner and 1.1Gs in acceleration

A few tweaks this week and back up for another two-day weekend next weekend

That is an interesting trailer. I wondered why the axle was so far forward. Does the trailer pivot on the axle. Looks like there is a release handle up front. I assume you just drive the car on till the weight on the car pushes the front end down?

I didn't know the race pax recorded all that info. That's a cool little feature. How did that 1.7G feel? Sucks about the videos.

Oh and thanks for the info on the steering rack.

you got it - the trailer tilts back so the car can be driven right up on it and then as the cars center of gravity passes the pivot point it tilts back down. I had the trailer made longer than I needed to get a better angle of approach so when the car is really low I'll still be able to get it on the trailer without a lot of effort.

it's amazing how much data the racepak will record - thats just the basic stuff that comes stock out of the dash and from the ECU. I'm plotting for some shock movement, & steering sensors and a few other things so I can know exactly what the car is doing.

It's pretty crazy going that hard sideways, it felt great . Compared to a lot of the other fast autox cars its a lot more comfortable to drive fast as it doesn't have a turbo wake up or crazy aero effect yet so it can be driven progressively harder instead of having to drive it crazy hard or it just doesn't work like some cars.

I'll be sure to get videos from next weekend!

I kind of figured that. That's a very clever idea. Can you take some pictures of the pivot point and the latch used up front? I may build one of these trailers just for the locost. Alot better then having to drag out ramps. Thanks again.

How much does that trailer weigh? It looks really nice.

What engine/transmission is in your Audi? I'm still curious if my Jetta can tow the locost when it's done...

Its an allroad so its ether a 2.7l twin turbo or a 4.2l v8

thank you! somewhere around 1150lbs according to the scale weight from the manufacturer




turbo nailed it - it's the 4.2 v8 with a 5 speed auto behind it. towing much more than about 1500lbs with a jetta is going to be tough - you'll need the euro hitch and even with a vr or a 1.8t (or the 2.0t) you're going to be asking a lot out of those with that extra weight behind it.

So late but not forgotten - here is the video of my roomie driving at the last event in packwood

http://youtu.be/aqZORaRjzFg

Still having trouble with the way the data logging takes a few seconds to start. I hooked up the VSS on the transmission and got that working and have the logging start on that but there is still a dead time where it starts up. I'm going to see about wiring up a rocker switch that feeds in and enabled & disables the telemetry. It wouldn't be an issue at all on a race track but on a 60 second autox course it's a pretty measurable portion of the run and it really weirds out the GPS.

new (proper stock) redline worked nicely. less rear camber did NOT work well, rear was all over the place - I had the ride height up to match the front - unfortunately that means i'm getting positive camber in compression. I lowered the rear down to where it should be to try that but corded one of my tires before I had a chance to try it out. oh well, next weekend...

aside from the rear skittering around like it had ice skates the car ran well all weekend.

I'm considering trying some kevlar/fiberglass for the rear deck & fender pieces (deck splitter, gurney flap, whatever it's called) and also looking at ways to get my front end lower, I think i'm going to have to redo my front arms - which of course gives me a good excuse to go to spherical joints and get rid of those giant rod ends on the outboard.

After cording the A6s I went back to my used FE compound 22x10x13 hoosier slicks. I ran them a lot lower on tire pressure than the first outing (teens instead of ~30 psi) and was able to actually get some heat into them.

on top of that the rear suspension being in it's proper movement range meant the car worked appreciably better - like how I have been expecting it to work.

the previous weekend i was out when I corded the A6s I was off ~4 seconds from the fastest guys. last weekend I missed FTD by 9 thousandths.

One of the newbie competitors brought a photog along so I had some out of car pics - which was good since I forgot to bring the card for my video camera...


DSC_0199_2 by Evan&Monica, on Flickr

over driving those brakes a bit after the straight

DSC_0598_2 by Evan&Monica, on Flickr


DSC_0581_2 by Evan&Monica, on Flickr

The car is still about 2 inches higher than i'd like it, I'm going to have to at the very least redo either the pickup points or the control arms to resolve that. I think that will be a winter project. I picked up a tire in an unusual spot during the run and bottomed one of my rear shocks - both things to sort out as well before I head out to the next outing.

It towed the car without a hitch? Now that's a little wagon with mad skills.

I sure enjoyed the ride you gave me. That's one strong running Locost.

Time to get the car ready for it's last few events for the year.

I've been wanting to get the car scaled for a long while and haven't been able to setup any time with friends that have scales. I figured it would be worth figuring out my own set of scales in case I wanted to try different setups. Well I sure didn't want to spend ~1500+ on a good used scale setup.

So off to amazon and looking for high rate bathroom scales. I found some scales rated at 400 lbs a corner for a good price. Went about making some levelling pads for them as I know how important dead flat is for corner weighting a car.

Finally got everything setup today and got the car scaled and mostly cross weighted - I accidentally rolled the car forward off the scales instead of back onto the boards on my last go before checking my last fine adjustment and called it a day.

75 bucks worth of scales that are surprisingly accurate & consistant, 45 bucks in metal because I bought it at lowes instead of going to the metal yard, 5 bucks in wood from the scrapper at home depot and some chair levelers I had left over from another project and I have scales and pads that I can reuse use for the longacre 12x12 scales if I ever want to upgrade.



close up


Car weighs 1302 as it sits, no hood & half tank of gas. ~54% rear bias as it started - better than I expected.

After I ballasted for myself and did the cross weights rear bias went to about ~58% and I was able to get to ~50.8% cross weight down from ~54.5%

Car with me in it is ~130 lbs over minimum weight. I'm planning on dropping 50 lbs for next season. Switch to aluminum wheels should get me ~36, aluminum front hubs and hats should get me another ~10-15, aluminum hats and calipers in the rear should be another 10-15. so that will leave me ~10-25lbs over minimum weight. I'm sure the front & rear aero packages will add a few pounds so I"ll likely have to go looking to lose a few more pounds on the car. probably the passenger seat & harness as well as some shorter springs all around.

Next up is bump steer. I looked at various options to measure it from the more standard piano hinge plate and dial caliper(s) to the newer method of using a laser, a mirror & some geometry. After scouring town for a laser and a small mirror i'm going to give that a shot. requires a lot less tools and should be accurate in capturing bump & camber curves.

Nice numbers.

What did your wheelbase turn out to be?

Thank you sir, I'll have to check the numbers again but I believe it's currently 96"

Did bump steer tonight. LOVED the simplicity of the laser/mirror setup.

I did the low cost version of the ART system



mirror clamped on the rotor and a nice pink laser (only place I could find one anywhere in town was the pet store in the cat section...)



I knew my rack was too short and would cause bump steer. issues - looks like that's very true. I shuffled spacers up and down to find the best mid point and settled on that. I still have toe out in bump and little to no toe-in in droop transitioning to toe out - all standard issue with a rack that is too short.



I also dialed back my anti-dive to 0% - I'm not getting as much weight transfer to the front as i'd like - with brakes only doing 1.1G compared to ~1.7 lateral something is up and I'm hoping it's a combination of too much anti-dive and the now-better cross weights.

now back to solidworks aero testing

Are you willing to share your model? I have an offer to do some aero work on a Seven and then Car9, but my SketchUp models are not suitable and I don't have good bodywork yet anyway...