Spec Boxster Build

[thstone]

Originally Posted by Little "t"

Good job Tom, I'm looking forward to Willow this weekend, we are going to do some serious damage!

Little "t" and I will be back at Willow Springs battling the field this weekend! Look for updates here.

[The Radium King]

looked like there were some pretty rough pavement breaks that were unbalancing your car as well.

[thstone]

Originally Posted by The Radium King

looked like there were some pretty rough pavement breaks that were unbalancing your car as well.

The reason that I think that the majority of the oversteer was driver induced is that other times (as you can see in the video), I make the turn through that same corner cleanly.

In racing situations/conditions, I am finding that consistency is a challenge because everything continually changes due to the existance of the other cars. This is the biggest change from time trialing.

[The Radium King]

and perhaps a slight throttle lift-off in times of uncertainty through a corner (traffic, rough pavement) will lighten the rear and loosen it up.

[thstone]

Here is some racing video from yesterday's 12-lap sprint race with the POC at Willow Springs Raceway.

With a 12-car Spec Boxster field, I qualified 4th, then dropped to 5th on the first lap, moved up to 2nd when the 2nd place car spun coming out of Turn 9 allowing me to pass the P2-P4 cars. Then I was passed and moved to 3rd, and finally was passed by the points leader and ended up finishing at 4th.

Funny, but if I said that I started 4th and ended 4th you'd think nothing much happened - sometimes its not where you start or end but what happens in between that makes it all worthwhile!



Stone POC BSR Race WSIR 4 12 14 - YouTube

[com3dorm3]

Nice one! ... the adrenaline definitely kicks in during the black Boxster moment.

[BruceH]

Nice driving! Great footage

[thstone]

Here are a few pic's from the California Festival of Speed...

Traffic moving well on the 405 but there is sure to be a big back up at the Turn 3 offramp...


About to pass Doug at 130mph...


Racing through the infield with a 911 on my tail...

[thstone]

Baseline dyno performed this afternoon...

[JAAY]

is the car not strapped down?

[thstone]

Originally Posted by JAAY

is the car not strapped down?

Here you can see the strapping in front and behind the rear wheels (front chocks were added just before the runs).

[thstone]

Installation of the Top Speed Pro 1 (from Texas) catback exhaust started today. This will net an 18lb weight savings.

Chose the catback exhaust because the spec rules say that you have to keep the stock headers and I am going to keep the cat's since it is still street and smog legal.

As you can see from the photos below, access was pretty easy with the 4-post lift and having the rear bumper frame previously removed as part of weight reduction. Will finish tomorrow morning.

[thstone]

Finished install this morning. Looks great. Will drive it later today and post sound impression.

Will also get a comparison dyno this Friday and post HP increase.

[thstone]

Went for a drive this afternoon - love this new exhaust! Its not so loud as to wake the dead but it definitely give the car a roar that was missing in the stock muffler. Definitely a keeper.

[Nine8Six]

Originally Posted by thstone

Went for a drive this afternoon - love this new exhaust! Its not so loud as to wake the dead but it definitely give the car a roar that was missing in the stock muffler. Definitely a keeper.

I was convinced you guys got hit bad as well RE noise restrictions (circuit wise). You sure yours passes? Still got the cats right?

[trygve]

Every track is different as far as limits and enforcement go. For northern California, they now have 103db limits at Sonoma and Thunderhill. Laguna Seca is the worst, with each date getting a different sound limit; most dates are stuck at 90db-93db, and the county doles out a select few (incl. ALMS, Moto GP) at 105db. So glad they built golf course homes near a classic race track!

I had my Spec Boxster sound-checked at Laguna Seca with no cats and the Boxster S muffler, and it was 87db. The louder systems can exceed 103db, but most people get mufflers designed to stay well within the 103db limit, but have run into trouble with some systems that have filler that degrades over time and gets louder. Lucky folks who go places with no limits get straight pipes!

[rastta]

Originally Posted by trygve

Every track is different as far as limits and enforcement go. For northern California, they now have 103db limits at Sonoma and Thunderhill. Laguna Seca is the worst, with each date getting a different sound limit; most dates are stuck at 90db-93db, and the county doles out a select few (incl. ALMS, Moto GP) at 105db. So glad they built golf course homes near a classic race track!

I had my Spec Boxster sound-checked at Laguna Seca with no cats and the Boxster S muffler, and it was 87db. The louder systems can exceed 103db, but most people get mufflers designed to stay well within the 103db limit, but have run into trouble with some systems that have filler that degrades over time and gets louder. Lucky folks who go places with no limits get straight pipes!

Sonoma has now reduced sound to 100dB. Laguna only offers 90dB to HDPE's now - they have reduced it from the 93 dB. Thunderhill is still at 103dB.

I've never seen anyone get hit at Thunderhill over the 7 years I've gone there - and there have been some really loud cars. Same with Sonoma - but that may change with the new reduced limit. As for Laguna - it's by far the worst - but i've seen some pretty creative setups to meet sound

[Eric523]

All of the tracks in SoCal are open sound. This year the only track we hit with a restriction is Laguna and we will have a 105db limit there since we are running with the Pirelli Cup series full of cup cars.

[Nine8Six]

Interesting info. Knew about LSMR's low restrictions. I had friends over who were (complaining) saying 'most' of the circuits in the USA are now having pretty hard restrictions :/ He races fast & loud +200hp superbikes, in his case it is a nightmare. Good to know that it is less of a problem for some cars

In EU, some have already set their 'additional fees' for emissions (no cats = you are screwed). Not going to mention who as the policy haven't yet been implemented but according to some of the rumors... it looks like it is going ahead. Wouldn't be surprised you guys are going to be hit right after with "green" additional track side taxes

All good reasons to make extra cash huh... same goes for raising the dB for when some organizer pays more to rent the circuit. Somehow unfair for the smaller teams....

[thstone]

Sorry for the cross-post but I wanted to maintain some continuity in this thread.

Here are the results from the exhaust install:

1999 2.5L base engine, 135000 miles, underdrive pulley, LWFW, spec clutch, otherwise completely stock. ONLY the catback exhaust was installed, stock headers and cat's still installed (early cars like this only have one cat per side). No cat delete pipes. Nothing else was changed between the two runs.

Each major vertical gridline is 10 hp. Lefthand vertical axis (HP) not labeled for competitive reasons. A/F Ratio scale has been adjusted.

The green line is the stock muffler, the red line is the Top Speed Pro 1. The squiggly red line is the A/F ratio with the Top Speed exhaust. We did not measure A/F ratio with the stock muffler (other green line is flat).

Net result: +7hp @ 6150rpm. Peak +2 hp. All of the gains come above 5800 rpm. No appreciable difference in hp up to 5800.

I find the sound of the Top Speed catback to be awesome throughout the entire RPM range, though sound preference is subjective. The Top Speed exhaust also saves 18 lbs in weight. For $315, its a great deal.