2003 Suzuki GSX-R1000

Well, after spending more time on the 750, I found a couple of things that didn't really suit me. First, it felt like it had no torque unless you were up into 8-10k RPMs. On the track, this is a non-issue. On the street, it means you never get out of 2nd gear anytime you might need a quick squirt (i.e., commuting). The 748 was worlds better in this regard, having instant drive pretty much everywhere. The second big bummer was the ergonomics. The more I rode the 748 and the 750 back to back, the wider and more unwieldy the GSX-R felt. Inline-4 riders are generally used to having their legs splayed wide, but I just couldn't get comfortable with it in the end.

After hearing all about the 2003 GSX-R1000, and how much narrower it felt in the tank width department, I finally went to see what all the fuss was about. Jumping on an '03 750 and '03 1000 back to back showed just what a difference there was. Aside from the width, they've managed to make the seat much more comfortable. I found the 750's a little too pointy, as well as too soft. It was a dramatic change from the wide, and very hard Ducati seat. The 1000's is wider, but still softer than I prefer...

Anyway, at this point I'd already sold the 750, and was in the process of selling the 748 (looking for a 996SPS). I ended up buying the GSX-R1000 of course, and have since sold the 748 - which I miss already. There's definitely another Ducati superbike in my near future.

On the ride home, much to my joy, I discovered several bits of goodness:

I think this bike is much nicer looking than the '02 750 - the black wheels and frame are nice, as is the overall darker color scheme. The dark bellypan is a bonus also. I couldn't help myself, and took some pictures of the bike while it was still nice and shiny...

A trip to Thunderhill showed that the bike was capable of running respectable times, even on the stock Bridgestone tires. I didn't have much faith in them at first, but when pushed harder and harder, they definitely impressed. They don't hold on like a DOT race tire such as the Dunlop 208GP, but they're certainly better than other high-performance street tires like the 207RR.

The power of course was incredible, even putting the 750 to shame. But again it was the suspension which impressed. After getting the sag dialed in, a few clicks of compression and a few clicks of rebound sorted things nicely in the front. Out back, 3 clicks of rebound seemed to make things stick (although in the bounce test, the backend looked rather slow). The only problem I had was with the bike not wanting to finish the corner, and not wanting to fall in fast enough. I've since raised the forks a few mm (basically as far as you can go while still allowing the clipons full grip on the fork tubes), which has improved things a bit. I think the rear really needs to be raised, however. The next project is going through the suspension completely.

The very small list of modifications to date include:

November 21, 2003

After putting some miles on the bike (~1,400), I took it down to G-Force Performance to get it dyno'd. Frankly, it made silly power: 152.6hp, and 80.1ft-lbs of torque. It's no wonder why it's a much nicer bike to ride on the street - at around 3800rpm, it's making more torque than the 750 did at peak!

Here's the dyno graph:

December 4, 2003

No one's ever happy with the power their bike makes, no matter how much it is, are they? Something about too much never being enough. Ah well...so I decided to go with a bolt-on can. I figured the stock exhaust was pretty damn good, and was already made of titanium (i.e., light), so the can was likely to be the bottleneck. I picked up an Akrapovic carbon fiber unit, and am well pleased with the construction (not to mention the fruity, but not obnoxious, sound).

It was back to G-Force to see what it did, and if I'd need to remap for it. With just the can, no remap, no nothing, it made 156.9hp and 81.7ft-lbs of torque. Hard to argue with +4.3hp and +1.6ft-lbs of torque for basically zero work. Power and torque were up everywhere, with no loss at all. Here are the graphs:

Why just the bolt-on, and not a full system? Well...

  1. Cost. The price differential between a full system and a bolt-on was about $1000. I'm not made of money...
  2. SET valve. I plan to ride the bike on the street and at trackdays, not race it. As such, I appreciate the boost in low-end torque that the SET valve gives. Looking at dyno graphs from other '03 GSX-R1000's with full systems, it's obvious that the SET valve works. Even Akrapovic's own dyno testing on their Evo system shows substantial bottom-end loss in the pursuit of top-end power.
  3. Ease of swapping. Since I plan to run trackdays at Laguna Seca (where noise is severely restricted), being able to swap the stock can back on quickly and easily is a major bonus.
  4. No need to remap the fuel injection. I wasn't actually sure that this was going to be the case, but was hoping it would be. With a full system, I'd definitely have to do it.
  5. Value. Again, the stock header is so good, a full system versus the bolt-on would give very limited extra power, and only at the very peak RPMs.
I dug through the dyno graphs G-Force had on file for '03 bikes like mine, and found some interesting data. A bike with a full TiForce system and BMC air filter made 162.xx hp after a full custom map on a PowerCommander IIIusb. Another with just a Yoshimura bolt-on made 160 hp - no filter, no PowerCommander. The Yoshimura setup made much better power in the lower to midrange (think SET valve), and only lost out to the TiForce setup beyond 11k RPMs. Two horsepower at the very top of the rev range? You can see why I opted for the bolt-on rather than the full system (and subsequent remap it would require).

Another point of interest was comparing my graph to the Yoshimura-equipped bike. The graphs were identical up to 10k RPMs, where the Yoshimura just held onto the power a tad better (to the tune of 3hp). This person hadn't done a base run, however, so it was impossible to tell whether this was a function of our bikes or the exhaust cans; it'd be interesting to find out. Given the projected use of the bike, however, it's not very critical to me.

May 26, 2005

Well, time for an exhaust swap. Not because I think the bike needed it, but because Keigwins at the Track, who I instruct for, is now sponsored by Leo Vince. I received a beautiful titanium full system, with ultra-high mount can (so I can continue to haul students around as passengers).

First and foremost, the system is very nicely put together. The tubes are nicely welded, the insides are cleaned of flash, and there are no screwy, flow-restricting tight bends. The kit went together easily, and most importantly for me, the fit was perfect. There was no interference at the oil pan (which the headers hug quite closely), no touching of bodywork, no rubbing of radiator or oil cooler, etc. It may as well have been a factory part.

After installing the exhaust, I slapped on a Power Commander IIIusb. I ran it with the base map for a stock bike (not the zero map) for a couple of days, and then took it in to be tuned with a custom map. Turns out the base map was actually too rich almost everywhere! Not what you'd expect, but there you go.

So, how'd it do? Here are the graphs:

So what have we learned here? Well, the bottom line is, there was a gain of 2.1hp beyond about 10.5k RPMs. While nice, there was a big loss of power and especially torque between 4k and 5.5k RPMs (think SET valve). So, my original assertions were basically right on - for racing where you'll be spending all your time in the upper RPM range, a full system will do somewhat better. For street riding and trackdays, however, the expense just isn't worth it. The stock systems are so damn good, it really doesn't make sense to go with a full system for the street or occasional trackdays. Weight isn't even an issue with these bikes, as the stock system is already titanium. And, while I didn't weigh them back to back, I'd guess that the stock system (not including the SET valve motor and cabling) with the bolt-on might be a bit lighter than the Leo Vince full system. Crazy, I tell you.

The Power Commander mapping was definitely a good thing. If you're not going to remap your fuel injection, don't even bother with a full system - you're probably going to make worse power than the stock system, or at least a stock system with a bolt-on, anyway.

Also, take dyno graphs for what they are - only some of the data. For instance, while the power/torque curve isn't perfect, remember this is only at WFO. This doesn't necessarily reflect part throttle openings. What I'm saying is that while riding the bike, you don't feel most of these anomolies. And, if you're WFO at 4k, you're probably in the wrong gear...

Finally, it was noted that a high-pipe setup like mine is definitely not ideal for power generation. These setups, like the underseat routes, tend to compromise some on ultimate power (some more than others). One of these days if I get REALLY bored, I'll see if I can find a standard low-mount mid-pipe to bolt in, and see how much that high-pipe is costing power-wise. Don't hold your breath, though...

In summary, while I'm happy with the result, if I had paid $1200 for the exhaust, $300 for the Power Commander, and $300 for a custom map, I'd probably be substantially less so. Bolt-ons really are the way to go, for this bike at least. If your bike's stock exhaust isn't titanium, and/or just downright heavy (i.e., ZX-7R), a full system like this may make much more sense, however...

Last modified: Thursday, 26-May-2005 23:30:45 PDT
Questions/Comments/Problems: Paul H. Yoshimune