With a few hundred miles on our new Bridgestone RE-11 tires on an equally new quartet of lightweight Volk Racing RE30 wheels, it was time to bring Project Evo X, our longterm 2008 Evo GSR, back to the testing grounds.
We tested handling and braking only since those areas are what the new rolling stock will most affect. Acceleration testing was scratched. No sense subjecting the overworked stock clutch to further launching abuse for no good reason.
Here's what happened:
Braking (60-0), feet: 108
Slalom, mph: 69.9
Skid Pad, g: 0.93
Braking notes: Nothing new here. System requires a little heat before performance is optimal. No fade at pedal. Distance stable at 108-109 feet.
Slalom notes: Lots of grip but needs sharper response. It's a bit of a slog to get this car between the cones without overwhelming the obviously too-soft suspension. Needs more control.
Skid Pad notes: Counter-clockwise, the GSR can achieve a nice tail-out attitude all the way around. Not so easy to get this going clockwise, however. Still, chassis is sensitive to throttle inputs, which is nice.
Compare the above results to Project Evo's performance in October on stock wheels and tires: 113 feet, 70.3 mph slalom and 0.93 g on the skid pad.
The RE11's sidewalls subjectively don't feel quite as stiff as the stock Yokohama A13s and this is perhaps another contributor to the slightly slower slalom speed. More camber and roll stiffness will be required to extract the latent potential of the new wheel and tire combination. Indeed, the shoulders of the front tires were visually punished after testing, and we're clearly not best utilizing the entire contact patch of these wider RE11s.
It should be obvious what we're going to do next.
Engineering Editor Jason Kavanagh @ 18,404 miles.
subytrojan says:
05:34 PM, 04/ 8/09
Awesome! I hope road course lap times come at a later time. :o) Thanks, Jay!
mrak says:
05:43 PM, 04/ 8/09
that picture something not right..
Why the caliper is touch the wheel spokes?
I guess you should readjust your wheel or caliper set up.
stijockey says:
06:00 PM, 04/ 8/09
Wow, two tenths of a second slower through the slalom than the stock STI.
ace47 says:
03:40 AM, 04/ 9/09
^^ How can it be going slower through the slalom by two tenths of a second when slalom speed is measured in mph?
And no offense but you guys suck at modifying cars. You guys changed the aftermarket intake with another one and changed the aftermarket exhaust because the first aftermarket one was too loud. And yet you are still using the stock clutch and haven't even bothered changing the break pads (I know the brakes are working well, for now). Whats next?
You guys didn't even bother to install a set of coil overs.
I could have probably built a 11 second street legal car by now for the money you guys spent on the above car.
stijockey says:
05:54 AM, 04/ 9/09
oops, my bad. I should learn to read, but you get the idea-69.9 for the heavily modded evo vs. 69.7 for the stock STI.
joefrompa says:
07:06 AM, 04/ 9/09
.2 mph means absolutely nothing considering the cars were tested on different days, besides which Slalom is not truly an accurate picture of track times.
Take a look at the Tirerack's test of the Michelin Pilot Exalto A/S....best slalom speed, slowest track time, out of 4 tires tested on a BMW 325i on the same day.
The one thing that I love edmunds for doing with these posts is showing the absolute ridiculousness of stating one car is faster than another based upon differences of 1mph or .2 seconds in any test. It's all tires and alignment and drivers until you get the same driver on the same day on a track.
redliner says:
08:16 AM, 04/ 9/09
ace47s got a point, but hey, whatever makes you happy. Suspension or clutch upgrades should be next on the list. Or are you guys just waiting for the stock clutch to disintegrate, before you spend a 1k on a new racing clutch.
joefrompa says:
08:18 AM, 04/ 9/09
I'm not familiar with these EVOs; do you know for a fact that the stock clutch can't handle this level of power? Have they reported slipping and I missed it?
Joe
Jason Kavanagh replied to comment from ace47
10:17 AM, 04/ 9/09
ace47, no offense but you suck at your job too.
We've debunked exhaust myths. We've shown how more rubber isn't automatically better. We've added a crapload of power and the stock clutch is still holding it. Doesn't mean we won't change it anyway. We haven't yet changed the intake but there are myths to debunk there too.
What have you read so far that makes you think we're not going to address the suspension? I'm sure if we added coilovers on the stock tires, we'd hear all about it. Probably from you.
This is constant work in progress. You're nuts if you think we're going to the track shootout on stock brake pads.
But keep telling me how I'm doing it wrong, because it's really helpful.
platf1 says:
11:33 AM, 04/ 9/09
I'm with mrak: that's gonna end explosively if that's how close the caliper is to the wheel spokes.
t10 says:
02:27 PM, 04/ 9/09
The stock clutches are a little "iffy" on this car. I'm fairly amazed it's still in place given the power levels, etc.. I can certainly understand not wanting to do hard launch test trials for speed which wouldnt give much new information given recent upgrades.
I'm guessing coilovers are next though. I suspect an upgraded turbo will appear at some point to make it competitive with the GTR, though maybe someone is waiting for a certain division of an industrial conglomerate to release a "bolt on" version which has been rumored to be in the pipeline. In any case it is interesting to see a certain amount of experimentation rather than a bee-line made for the fasterst 0-60 time. I've learned a thing or 2.
colinfiedler says:
08:36 AM, 04/10/09
I am curious what kind of tire pressures you guys are running on those RE-11s. Autocrossing on my older RE-01Rs the tire pressure made a huge difference. I would try the test again at 40-45psi in all 4 tires. Not the best for driving on the street but it should make the slalom numbers better for sure. I am still waiting to drive on my RE-11s sitting at home, first event is next weekend.
subytrojan says:
06:41 PM, 04/10/09
colinfiedler, I believe the testing team uses the manufacturer's recommended cold tire pressures.
If you haven't read their "How We Test" article, now would be a great time to do so. :o)
http://www.edmunds.com/insideline/do/Features/articleId=130988
ace47 says:
04:58 AM, 04/12/09
J to the K- calm down.
"What have you read so far that makes you think we're not going to address the suspension? I'm sure if we added coilovers on the stock tires, we'd hear all about it. Probably from you."
Nope, wouldn't have been me. Suspension change before tyres would have made more sense, to me at least.
As someone already mentioned, the caliper and the wheel spokes are already dangerously close. What happens when you decide you need a better brake kit? What would be easier, get the best kit around and than find wheels that won't hinder the brakes or install a set of wheels then find a brake kit that won't obstruct the wheel spokes? Just a question, I know you probably won't be replacing the whole kit.
Sorry but in my part of the world, the first rule of modifying is, determine the level of power you want to make and then match the braking needs accordingly. Then we go about the suspension, tyres, radiators, fuel pumps, injectors and all that, depending on what we want i.e track car, drift car, drag car or an all round street car. Obviously it differs from yours which is okay. Like someone said, whatever makes you happy.
"ace47, no offense but you suck at your job too."
I'll forgive you for that one.
roadburner says:
08:34 AM, 04/13/09
"The one thing that I love Edmunds for doing with these posts is showing the absolute ridiculousness of stating one car is faster than another based upon differences of 1mph or .2 seconds in any test. It's all tires and alignment and drivers until you get the same driver on the same day on a track."
Exactly, just go to any HPDE and you'll soon see that the driver's ability is a much more important factor with regards to fast laps. I just love those wingnuts who buy a new car and immediately slap several thousand dollars worth of suspension and brake parts onto it; if the truth be known, most of them couldn't use 80% of the capability of the stock car...