eyesoreracing
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| 07-02-2009 07:36 AM |
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Welcome to MotoIQ everybody!
I'm going to run the official Project Silvia thread here to post updates and plans, swap ideas, take requests and answer questions.
First, let's start off with a short update, since most people haven't seen anything about the car in at least 5 years since I stopped doing updates in Sport Compact Car. If you imagine the car in the exact state it was in 5 years ago, and then add 5 years of sitting in the sun behind Mazda R&D, directly under the landing path of John Wayne airport, you'll get a very sad looking mental picture. That's pretty much reality.
Stickers peeling off in the sun, flat black paint faded to grey, rusty Brembos, spiders living everywhere, dash cracks the size of the grand canyon...
About a year ago I jump started the poor bastard, warmed it up and went out and layed stripes. She still works, and she's on the road to recovery.
I'm working on two different sets of stories for the car right now. First, I'm going through the original project car stories and updating them based on a few more years of experience. Back then, we knew, for example, how well the JIC suspension worked for the first week. Now we know how it works after years of abuse. I'll be filling that info in and posting updated stories as fast as I can.
At the same time, I'm working on a few new stories. A couple of interesting maintenance tidbits to help a 300,000-mile old Nissan withstand the rigors of track abuse (I've been though a lot of wheel bearings, and I've figured out what you need to do to make JIC's last), and a few more engine mods as well.
On the engine side, I've been frustrated with the amount of shifting I have to do at tight tracks like Streets of Willow. As wide a powerband as the Disco Potato turbo provides, it still needs more torque to let me stay in 3rd gear in some of the tighter corners. I've got an S14 head that I'll be swapping on. The variable intake cam timing should help bottom-end breathing without hurting my top-end performance. I have yet to see anyone do a direct A to B test of an S13 head vs. and S14 head with no other changes. I'll bet I'm not the only one curious about the outcome...
Thanks for reading, and I'll post more as quickly as I can...
-Dave |
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sticky667
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west covina
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| 07-02-2009 11:42 AM |
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is this the $2,000 budget car? or maybe it was 3k? it's been a while |
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eyesoreracing
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| 07-03-2009 09:10 AM |
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Yea, we're talking about this car:
When we first bought and converted the car, we did it for $3,000. That was the car, bodywork and SR20DET drivetrain. I'm not certain you could still get a half cut cheap enough to repeat that price, though. Even by the time we went to print with that story it was already questionable if we could get another half-cut cheap enough. Those were boomin times...
Of course, in the state its in now, the car costs more like $10-12K. That's expensive for a car with a Krylon paint job and a barely-functional electrical system. On the other hand, it's pretty cheap for something that will outrun Shiv Pathak's Lambo gheyardo around Laguna Seca.
-Dave |
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eyesoreracing
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| 07-03-2009 09:39 AM |
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Question from the peanut gallery on the bumper fire story:
Dave - you had mentioned at one point in that magazine about putting together a Koni/Ground Control suspension for an S13 (don't know if it was the SCC car or not). I'm about to install a setup made of these components and I'm curious exactly how yours evolved. Spring rates, which dampers, etc.
-Rittmeister
Damn fine memory you have there Rittmeister.
I did finally do the Ground Control suspension for my girlfriend's Sil80. The final setup goes like this:
Front:
Koni 8641 1453 SPGC strut inserts in front (the GC specifies Ground Control's own valving.) These inserts can be put in a stock strut housing, if you're comfortable with a little cutting and welding. I didn't have any stock housings, so I used Ground Control's housings.
Ground Control coil-over sleeves.
7" long, 2.5" ID, 300 lb/in eibach springs
Ground Control camber plates
Progress adjustable anti-roll bar.
Rear:
Koni Sport 300ZX shocks (necessary to go with the aluminum Z uprights I used back there--you can use 240SX shocks if you stick with the heavy stock uprights)
more Ground Control coil-over sleeves,
More Eibach race springs (can't remember the rate at the moment)
more Progress adjustable anti-roll bars.
Overall, I'm very happy with the results. The JIC setup on my car is still better on a smooth track, but on a bumpy track or on the street, the Ground Control setup is superior. There are quite a few other differences between the cars that make direct comparisons difficult, especially the difference in body rigidity between the hatch and coupe. Having both, I can say the difference is HUGE.
-Dave |
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smartbomb
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| 07-04-2009 01:17 PM |
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Are you going to fix the front brake bias issue that made me fly off the track? What about diffs? I don't like the Quaffe, it makes it hard to recover from power induced oversteer because the back of the car starts to wag around. Other than that, I love your car although the JIC's could use more low shaft velocity control, but they are sorta inexpensive dampers. |
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eyesoreracing
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| 07-06-2009 09:43 AM |
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Wow, Mike, it would be hard for you to be more wrong! Let me count the ways...
1: In most situations, the brakes are actually slightly REAR biased. I think you drove it in the rain, though, which meant there wasn't enough weight transfer to reach the point of rear bias. In that kind of situation they're front biased. I just ran Mazda Raceway Laguna Seca with some too-old Pilot Sport Cups that had no grip, so I had a similar experience. I flat spotted the front tires pretty badly that day. On good tires, though, overly aggressive braking tends to lock the rears, with predictably exciting results...
2: You're smoking pole on the diff. The Quaife is awesome in this application. If I put a tighter, clutch diff in the car, it would lose the sharp turn-in that it has now. A Quaife has virtually no pre-load, so the rear tires don't try to force the car to go straight as you turn in. That's a huge overall benefit to the car's handling. I have not had any issues with unpredictable wagging, but we might be dealing with different driving styles here.
If you jump off the throttle mid-slide, the Quaife immediately goes back to being an open diff. This can suddenly give the rear too much grip, snapping the back of the car back in line. Usually, it snaps back so fast that you overshoot and start a big tank slapper.
The trick is not to puss out and just power the slide out to its natural conclusion.
Now, if I were trying to drift, the Quaife really is the wrong diff. When you try to snap from one drift to another, the way the diff opens up off throttle causes it to snap too hard and makes it really hard to catch the second drift. Recovery transistions, I think, would be a lot smoother with a clutch diff.
3: Actually, I think the JIC's have TOO MUCH low-speed damping, and I have the dyno sheets to prove it. Somewhere... I think what you were feeling is the undamped tire bounce caused by the dampers' refusal to budge on small inputs. |
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smartbomb
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| 07-06-2009 02:37 PM |
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1. If your prop valve was calibrated correctly, it would help more in low mu surfaces. Under these conditions a prop valve makes the most difference. In the rain it had way too much front bias.
2. IMHO Quaffe diffs blow. A Salisbury diff thats tuned correctly to the car, driver and suspension kicks ass. You have to try a dialed in OS Gikken or a Cusco RS where the lock curve is dialed back as well as the initial breakaway torque and maybe some clutches are deactivated depending on how the car is working. Although the OS and Cusco have the most flexibility as you can adjust the lock up curve slope, Almost any Salisbury diff can adjust initial breakaway and deactivate clutches to affect the lock curve and total lock.
The Quaffe, slews around some degree of lockup and being an open diff. This is great on the front of a AWD car or a FWD car but on a higher powered RWD car, it gets into this weird wiggle. Thats I problem I have when I drive modded FDs, your car and any car without initial break away in the diff. Maybe it is my driving style but other people complain about the same thing. On a RWD car I late apex and get on the throttle hard, especially on higher powered turbo cars. If the car starts to step way out and I modulate the throttle, the dance starts.
The trouble with most mechanical clutch type Salisbury LSD's is that they come set at the factory for drifting with a fairly high initial break away and an aggressive lock curve. This tends to make them slow around a road course and tend to have a tail out cornering attitude as well as push on turn in. I think this is because most good mechanical diffs are Japanese and in Japan perhaps most people who get an aftermarket LSD get it to drift.
Take the time to set up your diff correctly and you can go 2-4 seconds a lap quicker over an unset up diff and get on the throttle earlier and turn in well. The car will still drift smoothly and with stability.
3. JDM Dampers with lots of low speed control? That would be a new one on me, you will have to show me the dyno sheets. On the other hand, lots of low speed damping force isn't the same as low speed control or sensitivity or repeatability in the frequency dependent low end of the curve. Remember I was telling you how critical control in the knee zone of the curve between 2-4 ins velocity is? This is the feel I am talking about.
To be fair, I haven't driven your car for a few years though and the only time I drove it on the track was in the rain under really bad conditions, green unwashed track and heavy rain before all the slick stuff could wash away. |
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Sootfoot
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San Diego, CA
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| 07-06-2009 06:28 PM |
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If this thread is an indication of the content we'll see on this forum it will probably be worth paying attention! |
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Wes
MotoIQ Staff
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Wisconsin
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| 07-07-2009 11:20 AM |
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This thread makes my head hurt.... |
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eyesoreracing
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| 07-07-2009 11:57 AM |
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I still think you're remembering your general distaste for Quaifes and applying it to my car. Mine does none of the stuff you're talking about. On the JIC's, here's a plot of the front dampers. Red line is near full stiff, blue line is near full soft (I had to disable the clicker to put them on the dyno, so I can't speak in terms of clicks.  JICs are not the super-linear crap that most Japanese shocks are, which is why I like them better than most Japanese shocks. Still, the adjustment range is pathetic, and I run them at full soft nearly all the time. Can you see what you want from this plot, or do you want to look at a potato graph? -Dave |
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smartbomb
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| 07-07-2009 12:12 PM |
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Thats not a bad curve or force, except that's a piss poor adjustment range. Now i know why the shocks that Joey and I had on our EVOs sucked, like you turn the adjusters and nothing happens. The shocks feel like steel rods.
I wonder how the adjustment works, I bet its christmas tree preload and not orifice size. |
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eyesoreracing
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| 07-07-2009 02:22 PM |
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Back to the brake bias question, I get what you're saying about the prop valve, but I suspect there are other, more important factors at work that might be muddying the brake bias issue. Specifically, I think the car is having a hard time keeping all four tires loaded all the time. That solid-rod feeling you complained about on the EVO JIC's? Same deal on my car. As a result, the car tends to bounce on the tires on a lot of surfaces where the suspension is reluctant to move over small surface imperfections, and I think that bounce is responsible for momentarily unloading a tire, here or there, under braking. That leads to premature lockup, and it can happen at either end of the car.
You might be right about needing a different proportioning valve, but I think that would be hard to tune without first getting the damping sorted. I don't want to chase a damping problem with brake tools...
I think the huge sway bars might also be contributing. When I was flat spotting tires at Laguna Seca, it kept happening at the same spot as I was braking for the corkscrew. I was braking in a straight line, but there is a camber change just before you turn in, and with my huge bars, that was causing the inside front wheel to unweight enough to lock the tire (again, the tires were too old and had lost all their grip anyway, so there wasn't any brake feel either). I think a softer, more compliant suspension would improve braking, but at what cost?
Maybe I should swap Sarah's Ground Control suspension onto my car for a track day and see how that works out. Wonder how she would feel about that...
-Dave |
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smartbomb
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| 07-07-2009 05:53 PM |
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The curve is good, it just needs some tweeking. I wish the damn shock adjustment worked. Time for some KW's! |
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eyesoreracing
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| 07-07-2009 10:05 PM |
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Latest Project Silvia update is live. Check it out:
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blackdbl0si
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| 07-09-2009 11:59 AM |
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Posted By Wes on 07-07-2009 01:20 PM
This thread makes my head hurt....
 I missed these guys... |
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yo vanilla
MotoIQ Grease Monkey
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Appleton, WI
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| 07-16-2009 03:19 PM |
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I can't believe you still have the car. I'm going to re-read a few project silvia articles now just because of this! |
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eyesoreracing
MotoIQ Super Genius
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| 07-19-2009 03:11 PM |
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Here's a little something about how to not throw away your JICs when they start looking worn out.
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eyesoreracing
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Posts:139
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| 07-26-2009 07:35 PM |
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The S14 head swap is officially on the front burner (aka workbench).
Here's a tip: see that pice of particle board under the head? I dropped wood screws through the spark plug holes and screwed the head to that board so I can move it from place to place without having to worry about scratching the deck surface.
I also just got the intake manifold I need to go with this head (straight from the Spriso warehouse, thanks Mike!)
Before you go bolting a new, old intake manifold on your car, be sure to look inside and see what kind of crusyness is in there:
ew...
I spent a few minutes visiting Mark at MD Automotive and scrubbing the manifold in his hot solvent tank. The insides look clean now, but even after all the scrubbing, the manifold still looks dingy and old. Easy trick here is just to get your aluminum bits as clean as possible, then hit them with aluminum-colored high-temp engine paint. The paint seals the porous surface so your greasy hand prints will wipe off next time. This makes a HUGE difference 3 years after you put the engine in the car, as it will still look clean and new. Just don't hit the engine with any brake cleaner, or the paint will melt off!
more updates as real progress occurs...
-Dave
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Rittmeister
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| 07-28-2009 09:40 AM |
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Can't believe it took me this long to see this... Dave, I won't vouch for my memory. We corresponded a few times via email, both when you were with SCC and after - my real name is Kent. I also remember talk in the mag (during a general project car update, coverage of the status of all the project cars at that time) of a chassis swap, but clearly that hasn't happened. I went with 8610s in the front, Eclipse shocks in the rear (externally adjustable) instead of S13 shocks - I'm using the stock upright. 400 lb/in front, 300 lb/in rear springs, Vorshlag upper spring perches and Tein pillowball upper mounts all around. The setup has only been on for a few weeks but I've been kicking myself for not doing it a long time ago. It handles FAR better than my old strut/spring combo and yet the ride quality is significantly improved. Other mods include an S15 helical diff, ST sway bars, and an S15 T28 with supporting mods. I suppose I followed your formula pretty closely, except where my teacher's salary dictated less expensive solutions to the same problems. On the other hand, I did do the chassis swap - my first car just got too rusty.  I'm very grateful to see that the Silvia is still breathing, and I'll look forward to seeing more updates, especially the head swap. My personal holy grail is a VQ35DE engine and tranny swap, but the likelihood of that happening is pretty low. |
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eyesoreracing
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| 07-28-2009 10:04 PM |
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I was going to do a chassis swap to a very clean, straight, one-owner coupe with crank windows and no A/C. I went all the way to Seattle to buy it, drove it down here, and then procrastinated for 3 years. Meanwhile, I built this car for my girlfriend:
and after making it perfect enough for her taste, I lost all interest in chassis swapping just to achieve niceness. Nice, clean cars are a huge pain in the ass. Krylon gives you freedom to park anywhere, to drop wheels off the track, and to never wash your car. I sold the clean, 1-owner car without ever doing anything to it.
Your suspension setup sounds pretty cool. What generation Eclipse shocks are those? I assume they're Koni Sports? And they bolt to the cast-iron S13 rear hub, not the aluminum 300ZX hub?
-Dave |
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