build diary

February 20, 2005:
Every moment of my time has been spent working on the book.
I'm trying to make it entertaining to read as well as technically useful. All this writing has meant that I'm not working on the Seven. Well, sort of. I spent today with the car strapped to the dyno, trying to get back my "missing" power. The second dyno run was 134 hp at the rear wheels, right where this engine should be. However, I had problems with a lot of variation between runs. Odd. The fuel filter was changed and a feed line rerouted as the car was starting to show signs of low fuel pressure again and that helped, but I still never hit that 134 again. It was a bit frustrating - but I gave up and started work on installing the individual throttle bodies that we have sitting on the shelf at Flyin' Miata. It took a bit of creativity to get them to work with the stock throttle cable but I have that sorted now. Eventually I managed to get them installed and the injectors proceeded to leak quite enthusiastically. It turns out that the special fuel rail also includes special little clips to hold the injectors in place. Very cool. Now, before I fire it up, I'll have to install new injector connectors (easy) and plug up a coolant line (easy). Then the hard part starts - can I get it to idle?

I've also been doing some shopping. The snowmobile trailer I used to tow the Seven to the track last time worked fine but it was quite an adventure getting the car on it. I've decided to buy a real trailer for the car. I'd build my own but I'm frankly just too short on time. I found a used one that has a 6x12' deck on it for not much more than it would cost me to build. It needs a bit of love but nothing major. I'm building my own little race team! Now, where can I park it?
entry 793

February 21, 2005:
Did I mention I have better things to do? Today I picked up my "new" trailer.
It needs a bit of love (don't we all?) but it should do the job beautifully. I also managed to get the Seven running on the new throttle bodies. It idles fairly well considering the rough state of tune and makes an intoxicating noise when I blip the throttle. Hee hee hee. Now all I need to do is determine if they're making more power than the stock part, and work out an air filter for them.
entry 794

Dyno time.
With the freshly built engine, I pulled 134 hp at the rear wheels. Woohoo! See it on video.
entry 795
I have better things to do.
But I've wanted to put these on the Seven for soooo long...
entry 796
My new trailer for the Seven.
Nothing fancy but it's perfect for what I need. Dig those wheels!
entry 797

February 25, 2005:
It's been busy at work, but I've been stealing a few moments here and there to work on the Seven.
It's been out for an initial test drive with the throttle bodies installed. Pops and crackles galore out the exhaust as the fuel tuning isn't even close to being correct, but the car runs. I'll put it on the dyno this weekend and see if I can sort things out a little more. There's also a bit of binding of the throttle plates that prevents them from closing 100% when cold, giving me a 2000 rpm idle. Still, the car drives and that's a start.
entry 798

Ready for a road test.
entry 799

February 27, 2005:
Not one of my more successful weekends.
I decided to start off by taking the Seven for a quick blast down the road to see how the fuel was set up. The fuel curves are obviously drastically different, so I pulled over and fiddled a bit. The car then absolutely refused to restart. A helpful Man With Truck took me back to the shop to grab the trailer and I brought it home. It has since repeated the trick - this time right in front of our shop doors - so I'll try it tomorrow morning to see if it's heat-related. I thought I'd found the problem but apparently not.

A mistake on my part meant a small hole in one of the radiator tubes, which stopped any chance of dyno testing this weekend. Well, it didn't have to. I managed to fix the leak but by that point I didn't feel like strapping the car to the dyno. A longer drive helped me dial in the fuel better so now it should be in the ballpark. Is it making more power with the new throttle bodies? I'll find out this week. I certainly hope so, otherwise I've wasted a lot of time.

Some bump steer testing proved to be inconclusive - an inch of rack height change brought about little change in the bump steer. Then, as I reassembled everything, I realised I'd forgotten to adjust the ride height for the boards under the front wheels. So all my testing was done incorrectly as I was at the limits of the lower suspension travel. It was that kind of weekend.

I did get some things accomplished, though. The trailer has now been fixed up with properly adjusted hubs, some frame reinforcements, a new place to hang my ramps and general fettling. It should be a nice little setup for the Seven as the car fits perfectly. Now all I have to do is register it! I also spent some time working on my girlfriend Janel's "new" Miata. It was modified with suspension and pretty much the entire Jackson Racing catalog. The 4" exhaust tip and drone at 3000 rpm was not to her liking, so we put on a stock unit and installed the rear springs properly. Much better!
entry 800

The trailer gets a makeover.
A mounting point for the newly modified ramps, reinforcements in various places and a repaired tire rack.
entry 801
Some bump steer testing.
entry 802

March 1, 2005:
The Seven stranded me today after I fixed the starting problem.
Well, I thought I had fixed it. So those throttle bodies are coming off. I just don't have time to sort them out before the various track days and trips coming up. Argh.
entry 803

March 3, 2005:
After about an hour of work, the Seven fired up happily with the original intake system.
It's a pity I didn't have time to work out the bugs in the throttle body setup. I'll have another shot at them later, probably in late April. Before then I have to finish the book, get the car ready for some real testing and chassis setup at the track and then take it to California. There's a track day at Pueblo next weekend. I'm going to be busy!
entry 804

March 6, 2005:
Partly for the book and partly because I didn't believe it could be correct, I put the Seven back on the scales today.
Yup, it is perfectly balanced when I'm in the driver's seat. Or when a limited slip diff and four dyno calibration weights are in the driver's seat, anyhow. The downside is that the car seems to have gained a little weight. The fuel tank was brimming and the new tires are noticeably heavy. Is that all? Well, other than gravel strategically placed in every nook and cranny, yes. Maybe it's time to start thinking about pulling some weight out of the car. Somewhere. I did raise the rear slightly so that the car sits level when I'm inside.

I spent some more time with the bump steer testing. Remember how I realised that my steering geometry was wrong some time ago? This forced me to move the tie rods below the steering arms, leading to the problems with the rod end limitations. Well, even with with my newly raised steering arms I still needed to either raise them further or drop the rack down. Maybe my measurements were done with the tie rods on the top of the arms after all. I suspect the truth is that I measured to the center of the arms. Regardless, I dropped the rack down about 1/4" (the limit without rebuilding the rack mount) and improved things fairly significantly. It's still not perfect but that will have to wait.
entry 805

The Seven goes back on the scales just to make sure.
It's gained some weight!
entry 806
More bump steer testing with an improved tool.
entry 807

March 8, 2005:
It was kind of cruel to mention that the car has gained weight and not actually mention how much.
It's at about 1310 lbs right now with a very full tank of gas. I had it up in the air today to do a "nut and bolt" check before the track day. I had been hearing a slight noise from the rear end on an abrubt application of power and I suspected the rear end was starting to come free. Sure enough, the bolt holding the nose of the diff had loosened off about 1-2mm. It's tight now. A few other bits and pieces were checked while the car was aloft.

Since the change back to the stock intake manifold, the car has been very well behaved. Well, once I fixed that one bad connection in an injector wire. It feels quite healthy and the weather right now is perfect for tearing around. It's going to be a lot of fun at the track this weekend.
entry 808

A view from underneath.
This is a pretty cool photo - I don't think I've ever looked at the car from this angle before.
entry 809
While checking for loose bolts, I noticed that there's not much clearance between my spring and sidewall with these tires! It's not a problem, but if I go with anything wider I'll need a different offset.
entry 810

March 11, 2005:
Despite the lack of updates, progress is being made.
A quick eyeball of the car led to a full rear alignment (you know how it is) and the trailer is now nicely equipped for the trip to the track this weekend. Lots of photos and information to follow - I'm going to have some fun under beautiful skies tomorrow!
entry 811

March 14, 2005:
That was a busy weekend for the little Seven.
Saturday was spent at the Pueblo racetrack. Last time I was there it was fun but I didn't make a serious attempt to set the car up. This time, a big justification for the trip was to sort the car as well as possible.

The first foray on to the track was a little unnerving. The car didn't feel as planted as it should and never seemed to take a set. My girlfriend Janel (who supplied her Jeep as a tow vehicle again, poor girl) was along with me and started to get motion sickness after a few laps. The performance of the car shocked her. She'd been in it on the street where it is noisy, rattly and full of little zings and vibrations. Given her affinity for warmth and the recent weather, she hadn't been in the car for some time. On the track, the ferocity and violence of the car was overwhelming.

Janel was able to help out with taking some tire temperatures, though. The rears looked pretty good but the fronts indicated a lack of front camber. That's the same thing I had decided after eyeballing them in the past. After a couple of tries this was dialed in and the handling of the car was transformed. The front of the car was utterly faithful to whatever you asked while the rear would move around wherever you wanted. Even in turn one - a high speed decreasing radius sweeper - the car was completely composed. I got a big silly grin.

Other cars at the trackday included several Mazdaspeed turbo Miatas as well as a couple of aftermarket setups. The Seven was able to run away from many of them including a 2000 model with a 14 psi supercharger. The one that caught my attention was a brand new Elise, though. It was the first time the owner had taken the car to the track and he was only running about 7/10ths in the corners. I was only able to get behind him once unfortunately because he was taking people for rides and only doing a few laps at a time.

One of the high points of the day was when I was driving Flyin' Miata's modified Mazdaspeed and I tucked in behind Bill Cardell driving the Seven. We had a great time playing around. I was obviously driving his car harder than he was driving mine but neither of us was hanging around. It's fun watching the Seven move around on the track. There's a surprising amount of body roll but it works well. Bill was impressed with the amount of leg strength needed for the brakes. With the new tires, it's basically impossible to lock up the wheels. I hadn't really noticed because I'm a wuss when it comes to braking. Maybe I'll put slightly different masters on.

Mechanically, the car was almost perfect. The air filter fell off once and pulled a sensor wire off with it. That was fixed in a couple of minutes with no harm done. One of the fender stays started to crack and the fender assumed some odd angles. I've already reinforced one, this was the other. No big problem. Janel came out for a few more laps later in the day and had no more queasiness - either my driving was smoother or she was used to the car. She did notice the car was much faster.

So, a fun weekend then. Oooo, we're not done yet.

Sunday morning I was at an autocross back in Grand Junction. The Jeep was still loaded up. It's embarrassing showing up with a "trailer queen" to an autocross but hey, I'd spent the last day on the track and only been home for 9 hours! I haven't been on an autocross course in three years and it's quite a different matter running the Seven as opposed to my Miata. Even a light launch gave me a lot of wheelspin and it felt as if I'd been fired off a catapult. The runs were pretty frantic and I had a hard time getting ahead of the car instead of just reacting to it. What really impressed people was the slalom - the best part of my autocrossing has always been straight slaloms and the Seven just tore through it. It transitions cleanly due to the light weight and of course those exposed front wheels take all the guesswork out of placing the car. The Seven was mobile enough that I could dance it around fairly well. I had some good competition from a turbo Miata that was driven well and a WRX with enough power to get serious wheelspin despite four huge Hoosiers. I was worried about the Miata but my last run was fast enough to win fairly decisively. Phew - it would have been quite embarassing if I hadn't walked away with that one. A Seven is almost purpose-built for autocrossing.

A good weekend. Some new videos have been added to the site.
entry 812

The new and improved trailer setup.
It's quite possibly the easiest-loading trailer ever.
entry 813
At the track I was joined by Flyin' Miata's new Mazdaspeed.
It's, umm, not quite stock.
entry 814
While it appears the tires are showing lots of positive camber here, the tire temperatures and wear don't say so.
The shape of the rear fenders does hide the position of the rear wheels.
entry 815
Bill took the Seven out for a few laps.
He seemed to enjoy himself.
entry 816
Some happy tires at the end of the day.
entry 817
More videos have been posted!
entry 818
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