so i accidently bought a car and started a challenge team last night. have questions.

sleepyhead the buffalo said:

So:  quicker steering box, dual element ply front, and single element ply rear?

Hehehe

I will say that it can understeer on long sweepers, esp increasing radius sections. Ian, the 180 degree right hander at the mid point of the course is where I noticed it most, but also in the two big left handers a bit.

But it is easy to combat that by throwing the car into a turn with trailing throttle oversteer and then catch it with the throttle again.

The car has incredible turn in and response, and it transitions really well. Since the understeer doesn't show up until steady state cornering (and let's be honest, there is very little steady state cornering in autox), that's why I think it is easy to not notice.

I do want to post some photos too however:

The tow bar Ian made is excellent. Functional, strong, easy to assemble, and looks good. Plus it bolts to the factory bumper mounts and we don't have to remove the front bumper to use it.

This makes pulling the car behind a minivan a very easy thing (just don't try to do a u turn in rural Michigan on a 2 lane that isn't quite wide enough...)

Here's the main issue with smaller rear tires... But as long as we use larger tires whenever the car is on the street we should be ok.

Here we are trying to set the timing but finding a pulley with way too many sets of marks on it... We still haven't found the right marks.

Here's a bad shot of the car with a 747 junkyard in the background. The location was remote, but freaking cool.

Seriously I think there were at least 10 747s in various states of 'decommissioning' on the site.

I'm pretty sure we never figured out the correct pointer and marks on the balancer either. I timed it by ear in the pits.

Dusterbd13-michael said:

I'm pretty sure we never figured out the correct pointer and marks on the balancer either. I timed it by ear in the pits.

Well, you did a good job! I might have to resort to pulling the #1 spark plug and finding compression TDC the hard way.

Neat Stuff, Fellas!

Pulled out the front suspension yesterday. We need to get our shock situation figured out.

Pulling the blown one was easy, but the good one that kept trying to reextend during disassembly was a beast:

Here's me using zip ties to try and keep in compressed. Didn't work.

Next I got angry and used a rachet strap:

Worked!

Why am I removing a good Bilstein from the car you ask? Because it's not in budget if the nitrous kit is to be in budget. And we think nitrous > Bilstein.

We are looking at improving the design of the front spring though, since the cheap shocks are just slightly different in diameter than the bilsteins.

Left horns are best horns!

Lots of work over the past couple weeks, not a lot of posting. So here's a big photo dump of stuff we've been working on:

Found TDC the hard way and set timing officially. Ended up advancing a couple degrees and really cleaned up the low end of the rev range. Still really hard to tell exact timing because even with a chopstick on the Piston there is about 4degrees of crank movement before we can feel movement. We tried to set our lines on the safe or "retarded" side of those 4 degrees. I bet we are darn close to 10-12 degrees advance at idle, which is the stock spec.

Next we turned our attention to making front suspension spacers. We didn't like the way the coilovers top mount was just clamped to the shock body, and we wanted something more secure. Here's our plan:

Aaaand it took us way too long to implement this, but we got it done and I think it's a good solution. 

Now the spring sits on the spacer and the original unibody top perch, and the shock still goes through the middle. We no longer have adjustability other than just reducing the size of the spacer on one side. But once we corner balance it doesn't need to be adjusted anyway.

Race height:

We were getting no fluid at the rear calipers. But there was fluid at the front of this guy. So we removed and took it apart. The Piston had been jammed too far down and cocked in the cylinder. Since we're pretty sure this is a cheapo the tolerances may not have been adhered to during manufacture... Anyway, I manufactured my own spacer out of an old washer to prevent the Piston from bottoming out anymore. We also found out that the knob says clockwise for more pressure but that is 100% incorrect. Clockwise for less. According to Amazon reviews of what looks like the same valve we are not the first to discover this.

Reinstalled, rear brakes bled just fine! Woohoo working brakes.

Next we swapped the shifter out. The one on the right is from Patrick, he gave it to me for budget $free when I was out at his place and mentioned the shifter we had was a mess. 

There is so much slop in all the rods, holes, plates, etc we were not confident the new shifter would be any better. 

Boy were we wrong!!! I was able to adjust the new shifter so the r-1st selector arm was just ahead of the 2nd-3rd arm, and combined with spring pressure in the shifter the 1-2 shift is now as simple as just pushing straight forward on the stick. Then 2-3 is just straight back. We can find all three gears easily and you can be almost positive you're in neutral when you're looking for it. 

Thank you so much Patrick, this is a huge driveability improvement. 

Im going to have to look close at the flat tow setup you made. Have a couple that will need diy solutions for moving between shops.

To piggyback on Robbie's post.  We made insane progress the past 2 weekends.  The sorting process is almost as laborious as the build process (I can't imagine building and sorting a car of this caliber from scratch in a single year/driving season).

To begin, as Robbie indicated, we had to revamp the front spring/shock design.  The starting design was solid, but the parts required to execute to perfection were out of the budget.  So Robbie and I noodled on it for a little while, and got to hacking.

Here's what we ended up with:

With entire assembly installed:

The new design greatly reduces complexity at the expense of eliminating adjustability intent of prior design.  However, servicability has gone through the roof, and we can now just jack up the car and swap shocks/springs with 2x 9/16 wrenches.  In the future we will try different spring rates, so this is quasi future proofing the car while making it more reliable than the collar/inverted tube design we had (shocks were upside down, and consequently blew out).

Here is how the car sits with a driver in it.

Never get tired of this angle...

Which brings us to our next update:  Drag slicks.  As you can see in the above picture, we were test fitting the rear slicks and wanted to see what it looked like on the ground.

Being from Detroit and in the car industry, there is a lot of racing here at the shop/office.  With that being said, getting help with parts and go-fast goodies is one of Detroit's strengths.  One of my colleagues (Kyle) offered up a used set of Hoosier D06 Drag slicks in 26' diameter on the free.  However, the tread on one of them is "meh" so we might actually opt out for the 28" slicks we got from Dallas back in NC.  I purchased a set of Weld wheels with 28"x 10.5" from Dallas while picking up the car.  This was an incremental purchase and they did not come with the car.  Since they did not come with the car, it was not in the budget.  To correct this I was able to sell the Weld wheels the slicks came on for entire amount spent, so the slicks will be budget free!

While on the topic of drag racing, as Robbie already outlined, we were a little uneasy about our shifter situation with respect to making good shifts on the drag strip.  Robbie and Patrick got us sorted there, so I won't add anything to that except here is another angle of the dangle.

While Robbie was under the car making adjustments on the shifter, I decided to make myself useful and redo the connections on the fuel pump.  They started to corrode due to some of the weather the car has encoutered on the way to/from the track.

Also needed to create some clearance on the rear lower shock mounts.  This is the closest thing to the ground, so gaining any space we can is ideal since our autocross setup relies on 23" tires (read small).

Another random shot of the new front spring/shock setup (no pics from before sadly...).

Hey Rob, whatcha doing in thar?

Why are you so smiley?!  What's so funny?!

Ohhhhhhhhhh, I see now...might wanna turn that bottle off dude...

One of the biggest improvements we made will no doubt be the addition of nitrous for the drags.  Again, with Detroit being a big racing town, I was able to cruise over to FB Marketplace and score a $200 NOS Powershot square bore wet nitrous setup.

After much research, we decided on a momentary switch actuated by your thumb on the shifter (in lieu of a WOT microswitch) was a better solution for our setup presently.  We may want to NOT actuate the nitrous at WOT while we launch/pedal the car; and/or actuate the nitrous at not-WOT.  Lets hope the gearbox/clutch/driveshaft and motor are up to the task...

Kit fits like a glove, the fuel pressure regulator had an additional unused port, so we bought the right fitting and hooked up the fuel, now to just run the wiring. Nitrous line was included in the kit, so plenty of line to run, but will have to hide the additional line under the dash.

My cousin Trent getting in on the action with his outstanding attention to detail and wiring skills.  Good lord it came out to be quite the clean install underhood.  10/10.  Minus the solenoids, you can't even tell it has Nitrous.  With the aircleaner on, you may not be able to tell at all...

Robbie said he felt like a fetus for the 2+ hours he was playing dash monkey.  It was quite the task drilling the diamond plate and wiring up the shifter with the cage and seat installed.

The shifter came out great and Robbie did a hell of a job running everything.  Pics below is basically all done (minus hiding extra nitrous line).

The car was originally built with Nitrous in mind, so the car came with Autolite 104 plugs (1 step colder) so we just had to pull the plugs and regap them down to 0.035-0.040".

Very proud of how everything turned out on the N20.  The button/shifter is perfect and ergonomic, the underhood install is perfect and clean, nitrous bottle mounted next to driver to make sure the driver can reach the valve (not to worry, nitrous blow down tube is vented through the floor in case of malfunction).

RACEC4R said:

Robbie said he felt like a fetus for the 2+ hours he was playing dash monkey.  It was quite the task drilling the diamond plate and wiring up the shifter with the cage and seat installed.

 

I warned Michael and Dallas how much of a pain it would be to do any interior work once the cage was installed!!! That dash MAY be stainless diamond plate...

My picture dump was interrupted because I had to jump on a plane.

Here is solenoid wiring in progress using scrap wire from old projects. Save those connectors folks!!

And then completed:

In reply to Robbie :

Well not quite complete, we also cleaned up the wire going through the firewall. Here's a pic that includes the fuel line routing:

Robbie, what...uhhh...what are you doin there?

(More on this later)....

Love that angle grinder disc caddy!

In reply to maschinenbau :

Thanks! It's made out of a piece of a harbor freight furniture dolly (I buy them just for the casters) and two studs from an old box of bolts. The bolts might be from a 5.0l Ford.

Last night I finished the gas gauge install (a gas gauge doesn't seem important in a race car until you are diagnosing a stutter during turns for an hour or two before someone says "it sounds like it's running out of gas" ask us how we know).

So since I had this old gauge sitting around doing nothing, in it goes! Also, we first hooked it up with power from an always hot source, not a source that was controlled by the battery cutoff switch. So this gauge was sitting in the garage, on, for about two weeks. I noticed last night when I grabbed the gauge and it was slightly warm...

Anyway, now it's in, and on its own switch, and it looks like we need to add some gas...

On:

Off:

We chose to install at the rear of the car because that is where we fill gas. And having the gauge back there will let us know how much is in the tank as we are filling. We don't really need to see it while driving. Also this hole in the unibody was very nicely sized...

Robbie said:

Last night I finished the gas gauge install (a gas gauge doesn't seem important in a race car until you are diagnosing a stutter during turns for an hour or two before someone says "it sounds like it's running out of gas" ask us how we know).

Yep.