The simple upgrades that made our Porsche 997 faster on track

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Update by Tim Suddard to the Porsche 911 Carrera project car
Jan 26, 2023 | Porsche, FIRM, 997, 911, Porsche 911, Tire Rack, hawk, Florida International Rally & Motorsport Park, Bridgestone Potenza RE-71RS

Could we make our Porsche 997 better on track without destroying its street manners?

That was our goal with this project. We picked up this 2007 Porsche 911 with the intention of having a car that could do it all, from the daily commute and classic car tours to morning meetups and, yes, the occasional track day and autocross.

[Does trying to improve a car run the potential of ruining it, too?]

We wanted it all: speed, comfort, practicality, reliability and looks. Could this one car do it all?


As soon as we fetched the car, we had one big job to tackle: replacing the old, aged-out tires. We mounted a fresh set of the Bridgestone Potenza Sport, a proven, high-performance model with high marks from Tire Rack.

Why not make the initial jump to a 200tw model? We figured we’d get the car more or less back to stock for those baseline runs and impressions. Where Tire Rack puts the 200tw tires in its Extreme Performance Summer class, the Bridgestone Potenza Sport lands in the Max Performance Summer class–so it trades a little bit of performance for street manners.

We found these tires to be very well suited for road use: civil, grippy and with crisp steering.

We also ran these tires at the Florida International Rally & Motorsports Park, our regular test track. Our own J.G. Pasterjak, who handled the driving, came away impressed after just that first simple upgrade. “The car is so good that there is no way to do anything to make it better without ruining it,” he reported while running a 1:23.15 lap.


Of course, more could be done: “You might want to put a slightly larger or wider front tire on the car and/or a bit more negative camber in the front.”

To fit more tire onto our Porsche 997, we replaced the stock Lobster Claw wheels with flow-formed Apex SM-10 alloys: 18x8.5-inch fronts and 18x11-inch rears.

We wrapped those tires with a sportier model from Bridgestone’s catalog: the Potenza RE-71RS in 245/40R18 (front) and 295/35R18 (rear). Now we’re stepping up to a 200tw model–and a competitive one, too.

[200-treadwear tire test | Bridgestone Potenza RE-71RS vs. Falken Azenis RT660]

We also changed the oil, fit a new air filter, and sent the car to the alignment shop.

For brake pads, we replaced the originals with the Hawk HP+, a familiar model that Hawk reformulated in July 2018. The new compound promises less pad wear, less rotor wear, less dust, less noise and more temperature resistance.

During our first session with the new track setup, we started out with 32/34 psi cold tire pressures. That’s lower than Porsche’s recommendation of 37/43, but we knew that those pressures would quickly rise as we recorded laps.

During that first outing, the balance felt good, but the grip seemed to be lacking. The cornering loads also didn’t seem equal across the entire tread.

Based on past experience, we felt that the tires simply had too much air in them. We bled the pressures down to 31 front/35 rear hot and picked up another second with just that one change.

The outside edges of all four tires were the warmest, but that seemed to be a result of not having enough static camber. The treadwear now looked good.

The data said that 31/35 hot was a good combo, as cornering speeds were up pretty much everywhere, particularly on fast entries. Credit that to better feel and predictability. The additional grip sped up corner exits, which produced more top speed down the subsequent straights.

Based on the data and our experience, for track use we’re going to roll out with 28 front/32 rear cold pressures; then we’ll adjust after that first session with a target of 31 front/35 rear hot.

Oh, they’re fantastic,” J.G. said regarding the Bridgestone’s track manners. “I think they would go off some after a couple laps, but that second lap is awesome–like a Yokohama, but it needs less slip angle to work well.” Good steering feedback, he added.

As we did initially, during this return visit we ran back-to-back hot laps. The goal was simply to get a fast lap–think time trial more than endurance racing.

The Hawk HP+ pads performed well during this session. “They felt good,” J.G. said. “More bite than the stock pads but about the same total braking force.

They actually seemed to have a bit more bite when they were cold than once they got some heat in them. So, your very first hard stop could sometimes trigger ABS when you weren’t expecting it. But once they warmed up, they had a nice pedal, and I didn’t drive them long enough to fade them.”

But they might not be civil enough for everyone, as they’re noisy at light applications when warm and dusty all the time. He’d give them a 7.5 out of 10 for both road and track use.

With all that weight in the rear, he continued, it takes slightly longer to load the front tires, so he needed to make an initial brake application of about 85%, then sneak up to 100%. The release felt very nice, though, and the data shows that the pad displayed predictable trail-braking manners.

Our max braking g was a little lower than I’d like it to be,” J.G. explained, “but maybe that’s just being bit conservative with an expensive street car.”

The work done for this test–including the new Bridgestones on the wider Apex wheels plus the Hawk HP+ brake pads and performance alignment–dropped our Porsche’s fast lap from 1:23.15 to 1:21.45. Optimizing the tire pressures trimmed our fast lap to 1:20.23.

Before the work, our Porsche 997’s lap times at the FIRM landed between those of a new VW Golf GTI and a current Subaru BRZ. Even though the Porsche is still fairly stock, it’s now running with cars set up for track work, including our Triple Threat ND Miata and Toyota MR2 Turbo–cars, we should add, that can be driven a little harder with less worry of balling up something at the pricier end of the spectrum.

[The Grassroots Motorsports ultimate guide to track car lap times]

But J.G. added that more could be done to lower those lap times: “I bet shocks would do it some good. It hated curbs.”

Upgraded dampers could also help with another issue. “I’d say, at this point, the friction part of the brakes isn’t the issue,” he said. “The car has a slight instability on hard initial application, but I think that’s more chassis and inherent 911 stuff than brakes. I’d love to be able to play with bias, but without changing a bunch of parts, these are darn good brakes and quite user-friendly.”

More front grip could also help lower lap times. Maybe another degree of camber is the magic ticket there. Moving to GT3 adjustable control arms will get us there.

So, where are we? Without hurting street manners too much, we cut 3 seconds off our lap times.

The downsides? The brakes are noisier and dustier than before, but at least we now have a reference point.

More work to come? Likely. But at least now we have a 997 that can handle some track work without taking an offensive hit to its street manners.

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Comments
docwyte
docwyte PowerDork
1/26/23 10:28 a.m.

I run 32F/34R hot tire pressures in my 996 Turbo.  I start out with cold tire pressures of 24F/26R on NT01's.  Hate to tell you I told you so about the brake pads, but, well, HP+ pretty much stink at everything.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
1/26/23 10:53 a.m.

Next article: "How some bolt-on suspension upgrades make a $28,000 2023 Miata perform as well as a modified 15 year old 911 with over 300 hp" :)

Colin Wood
Colin Wood Associate Editor
1/26/23 11:31 a.m.

In reply to Keith Tanner :

Might be worth putting that comparison test down in the ideas book.

CrashDummy
CrashDummy Reader
1/26/23 11:38 a.m.
docwyte said:

Hate to tell you I told you so about the brake pads, but, well, HP+ pretty much stink at everything.

What am I missing? J.G's quote in the article was "...these are darn good brakes and quite user-friendly.” 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
1/26/23 11:38 a.m.

They do share one thing: Miata drivers have been getting their butts kicked by minivans since day 1.

https://grassrootsmotorsports.com/articles/soccer-moms-revenge/

 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
1/26/23 11:40 a.m.
CrashDummy said:
docwyte said:

Hate to tell you I told you so about the brake pads, but, well, HP+ pretty much stink at everything.

What am I missing? J.G's quote in the article was "...these are darn good brakes and quite user-friendly.” 

“They actually seemed to have a bit more bite when they were cold than once they got some heat in them. So, your very first hard stop could sometimes trigger ABS when you weren’t expecting it. But once they warmed up, they had a nice pedal, and I didn’t drive them long enough to fade them.”

But they might not be civil enough for everyone, as they’re noisy at light applications when warm and dusty all the time. He’d give them a 7.5 out of 10 for both road and track use.

CrashDummy
CrashDummy Reader
1/26/23 11:50 a.m.
Keith Tanner said:

Next article: "How some bolt-on suspension upgrades make a $28,000 2023 Miata perform as well as a modified 15 year old 911 with over 300 hp" :)

I'm curious what the total cost to recreate this 911 is at the moment. Are we in the same ball park as the "triple threat MX-5" or is the Porsche way more expensive for the same lap times because Porsche? I don't think Andy has done anything to that Mazda that would really hurt its street car manors too much. 

I think the ND2 has great potential as a future low-budget track car but right now it's hard to justify spending a little more to get the Mazda when you could grab a C5 Z06 slightly cheaper. That's if track is your primary focus. I'm sure the Miata is a nicer place to sit. 

CrashDummy
CrashDummy Reader
1/26/23 11:58 a.m.
Keith Tanner said:
CrashDummy said:
docwyte said:

Hate to tell you I told you so about the brake pads, but, well, HP+ pretty much stink at everything.

What am I missing? J.G's quote in the article was "...these are darn good brakes and quite user-friendly.” 

“They actually seemed to have a bit more bite when they were cold than once they got some heat in them. So, your very first hard stop could sometimes trigger ABS when you weren’t expecting it. But once they warmed up, they had a nice pedal, and I didn’t drive them long enough to fade them.”

But they might not be civil enough for everyone, as they’re noisy at light applications when warm and dusty all the time. He’d give them a 7.5 out of 10 for both road and track use.

I guess I read that as "obviously there are compromises with any pad that needs to work on the street and on the track but these are pretty good" rather than "they stink at everything". If the GRM crew continues to experiment, I'll be interested to hear if they find a pad that they think is an upgrade on both the street and on the track. 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
1/26/23 12:08 p.m.

In reply to CrashDummy :

Andy's car will still be quite good on the street. I'm pretty familiar with everything he's got on the car other than his choice of sway bar, and about the only downside to that will be a little more head toss. I've done thousand mile days in NDs with the same spring/shock setup and with the same wheel/tire size package. Based on my experience with a stock 997.2 S, the Miata could very well ride better.

You don't need to start with a new Miata to get that ND, they haven't changed appreciably in the past four model years. The $28k is for a brand new, fully warranteed car and nothing Andy has done should void the powertrain warranty. 

GRM hasn't disclosed what they paid, but Tim hinted that he got a 20% discount on a $50k car. So if you're not Tim, you're at $50k. The cost of most of the mods aren't disclosed, but I'll bet total cost in mods for the Miata and the 911 aren't that far apart. Tire cost going further will be about 50% higher on the 911.

The C5 Z06 has been the "cheap speed" answer for some time, but the newest ones are 19 years old now so they're going to be a different ownership experience than a new Miata. I'm not sure they actually are any less expensive than a new Miata anymore, and the bottom end of the C5 Z06 market is higher than the bottom end of the ND2 market at the moment. You can still get a C5 Z06 for $20k, but only if you like salvage titles.

CrashDummy
CrashDummy Reader
1/26/23 12:23 p.m.
Keith Tanner said:

In reply to CrashDummy :

The C5 Z06 has been the "cheap speed" answer for some time, but the newest ones are 19 years old now so they're going to be a different ownership experience than a new Miata. I'm not sure they actually are any less expensive than a new Miata anymore, and the bottom end of the C5 Z06 market is higher than the bottom end of the ND2 market at the moment. You can still get a C5 Z06 for $20k, but only if you like salvage titles.

Maybe I'm looking in the wrong place for used ND2s! I did a quick autotrader search within 500 miles of me in CT. Cheapest manual ND2 was $24,200. Club models (do you need this to get the LSD?) started right around $26K. Same search for C5 Z06s showed good cars starting around $25K, although some went way up from there. If the sub-$20k Z06 ever really existed it doesn't anymore but the ND2s don't look like they've depreciated much at all in my area. I'll be sticking with my NA for now while keeping an eye on what ND2 prices do going forward.  

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