Spec Boxster Build

[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.

[thstone]

Finally got around to installing a new 997 shifter ($250). This shifter isn't officially a "short shift" kit but the throws are about 25% less than the stock Boxster shifter.

My Boxster shifter has 210,000 miles on it (came with the blown engine chassis) and the bushings are so worn that the shifter just kind of flops around. This makes it hard sometimes to find the right gear on the racetrack.

Replacing the entire shifter and not having to mess with the bushings certainly saves time. And as you can see, my car doesn't have a center console so this job went really quick, like 45 mins (and I was definitely in no hurry).

The result is 150% improvement in shift quality! Not only are the throws a little bit shorter but the shifts are firm and crisp!

997 shift assy


Old shifter


New shifter

[thstone]

Well, with summer and hot temps coming I decided to take a look at the front engine cover. I have found that this cover radiates a huge amount of heat into the cockpit. On a cold winter day at Willow Springs, this is great. On a hot summer day at Willow, its like having the heater running full blast.

I bought some automotive insulating foam (EZCool - Automotive Car Insulation) and put two layers on the inside of the front engine cover panel using high temp industrial spay adhesive for bonding. This insulation is EXTREMELY light and the weight of the two layers was only about 4 oz.

I'll report back next weekend after racing at AutoClub Speedway if this helped to reduce cockpit temps.

As you can see here, the chassis has substantial insulation lining the interior of the engine compartment:


That is, everywhere except for the front engine cover - no insulation! Of course, in a street car this is normally insulated by the heavily insulated engine compartment carpet behind the seats.


Two layers of insulation;


The final product. Installed perfectly.

[rastta]

Originally Posted by thstone

Well, with summer and hot temps coming I decided to take a look at the front engine cover. I have found that this cover radiates a huge amount of heat into the cockpit. On a cold winter day at Willow Springs, this is great. On a hot summer day at Willow, its like having the heater running full blast.

I agree on the cabin heat. My boxster came with an integrated cool shirt system - but I took it out for the weekend we both drove since my wife had an instructor and I didn't want the hassle of taking it in and out.

Car was really hot as there are no air events in it anymore. Not being that familiar with the car - I didn't know that this piece comes off. Insulating it should work well. I might have to give this a try.

I'm also working on a way to draw air back into the cabin. I'll post pics when I start working on it.

[thstone]

Originally Posted by rastta

I agree on the cabin heat. My boxster came with an integrated cool shirt system - but I took it out for the weekend we both drove since my wife had an instructor and I didn't want the hassle of taking it in and out.

Car was really hot as there are no air events in it anymore. Not being that familiar with the car - I didn't know that this piece comes off. Insulating it should work well. I might have to give this a try.

I'm also working on a way to draw air back into the cabin. I'll post pics when I start working on it.

I also use a cool shirt system but still wanted to reduce the heat load in the cabin. To get some air into the car, I opened up the air vents under the front cowl. Its not a lot of air but it helps.

[rastta]

Originally Posted by thstone

I also use a cool shirt system but still wanted to reduce the heat load in the cabin. To get some air into the car, I opened up the air vents under the front cowl. Its not a lot of air but it helps.

That's what I'm going to do - I'm going to take a square duct - this one in fact



and put it in the passenger side air vent under the cowl - it should fit right in. Then connect a hose to it and have the hose come out under the steering column area. Also debating about putting one of these in-line - and have it controlled by a switch on my dash. I'll see how it does without a fan and go from there.

[thstone]

This week I received a $1,000 gift certificate towards a set of Forgeline Wheels for being selected "Rookie of the Race" at the PCA Festival of Speed in April. Always nice to be recognized.

[RedTele58]

Way cool!

Rick

[BruceH]

Very cool, congratulations

[rastta]

Very nice - congrats!

[thstone]

How to Go From 3rd to 8th in the First Five Corners

Since I started racing in February, I have found that I still have quite a bit to learn! No surprise there.

This video is from AutoClub Speedway on the roval. I qualified 3rd out of 10 so I have good basic driving speed but I'm still learning to negotiate traffic. I don't want to sound like I am whining but not one is cutting you any slack out there so you have to be fairly aggressive to make a pass - or to even keep the pace. If you are sitting back or get behind a slow car, you drop back like lead weight.

So, here for your enjoyment is an example of how NOT to start a race. I start 3rd and drop to 8th in the first five corners (about 1/3 of a lap).

What went wrong? Just about everything.

First, the pace speed at the start was right at the rev limit between 2nd and 3rd gears, so you'll see me shifting from 2nd, hit the rev limiter, shift 3rd, too low of RPM for a good take off, shift back to 2nd, on the rev limiter again, and so on. So I lose momentum on the start and lose a few positions as we accelerate down the front straight.

Second, I get held up a bit behind a 911 who is having a mechanical problem. Watch the world stream past me.

Third, with all of this happening, I fail to defend the inside line and get dive-bombed into Turn 3. Maybe this wasn't the best pass for the other driver to make but I saw him coming and gave him racing room. Again, I should have defended that line so he couldn't come up on me.

Fourth, I get squeezed at the apex of the next turn and have to slow and the car on the outside moves ahead. This was exactly what the other driver was supposed to do - force me to the extreme inside (while still giving me racing room) which allows him to roll through the corner faster on the outside.

All of this is incredibly exciting from the driver's seat and I'm having a blast out there even while I'm getting creamed.

Enjoy.



https://www.youtube.com/watch?v=HbavOhobKB8&feature=youtu.be

[jaykay]

Looking good Tom!