Most cost effective HP+ modifications?

[pothole]

Originally Posted by ProjectM96

True weight make a big difference. I think I read somehwere 0.2-0.3 second 0-60 improvement for every 100lbs lost. Problem with lowering weight-I drove without the engine cover carpet. I removed the carpet on top and the carpet behind the lower driver/passenger seat.

The car sounded horrible. It did not sound sporty at all. Those 5-10lb carpets make a huge difference in how good the engine sounds.

I thought of replacing front spare tire with Fix-a-flat spray, but idk how it effects my rim when trying to get a new tire? Has anyone used fix-a-flat? And I believe there are only 2 or 3 aftermarket rims for this car that are actually lighter than stock rims unfortunately.

All too true re taking the carpets out. Just makes the car sound rough as hell, doesn't it?

I drove round in the stripped out track-prepped BMW for three years. No spares, no gunk, just winged it.

Actually, I've never had a flat...

[Mrmaddbrad]

Originally Posted by ProjectM96

True weight make a big difference. I think I read somehwere 0.2-0.3 second 0-60 improvement for every 100lbs lost. Problem with lowering weight-I drove without the engine cover carpet. I removed the carpet on top and the carpet behind the lower driver/passenger seat.

The car sounded horrible. It did not sound sporty at all. Those 5-10lb carpets make a huge difference in how good the engine sounds.

I thought of replacing front spare tire with Fix-a-flat spray, but idk how it effects my rim when trying to get a new tire? Has anyone used fix-a-flat? And I believe there are only 2 or 3 aftermarket rims for this car that are actually lighter than stock rims unfortunately.

Haha well then take the weight from some where else :P Also, fix-a-flat is supposed to work if you also carry a bike pump and tire pressure gauge with you. The tire will still be flat after you fix the hole unless you reinflate it... But in reality, just get insurance that provides "free" towing. Tow it back to your house, take the tire to be fixed in another vehicle, call it good.

Flats are so rare, that i don't think the 20lb spare tire is worth it..... I've never had one, just avoid pot holes....

But the carrera 5 spoke wheels weigh A LOT less than the turbo twists that come with most boxsters...

[Overdrive]

Originally Posted by Mrmaddbrad

Haha well then take the weight from some where else :P Also, fix-a-flat is supposed to work if you also carry a bike pump and tire pressure gauge with you. The tire will still be flat after you fix the hole unless you reinflate it... But in reality, just get insurance that provides "free" towing. Tow it back to your house, take the tire to be fixed in another vehicle, call it good.

Flats are so rare, that i don't think the 20lb spare tire is worth it..... I've never had one, just avoid pot holes....

The oversight here is when one is travelling and isn't anywhere near home, which we have a few members on here who do, and is usually when life decides it's time for you to experience a flat tire. Jäger just recently went on a road trip over the summer that he shared with us on here, and he experienced a rear flat on the craptastic highways of OK not even halfway through his round-trip journey. And he had that car packed to the gills, but he didn't leave home without that spare.

One of those reasons why I don't beat myself up too much about not going with a 987...I still have a spare.

[Johnny Danger]

Originally Posted by ProjectM96

I looked at all the power adding mods available for the Boxster and added the HP claims all together. I excluded superchargers and turbochargers.

I got $90 per HP. Parts include performance intake, low temp thermostat, underdrive pulley, headers with sport cats, secondary bypass pipes, performance muffler, ECU upgrade, Pedro's Plenum upgrade, added 2HP for desnorkel and iridium sparkplugs.

I say most cost effective mods are ECU upgrade combined with performance intake and bypass pipes. $1700 for 20-25HP according to claims. That is about $78 per HP.

I can assure you that the above mentioned equipment alone will not achieve 20-25 hp . Not at the crank, wheels or otherwise .

[ProjectM96]

Originally Posted by Johnny Danger

[/B]
I can assure you that the above mentioned equipment alone will not achieve 20-25 hp . Not at the crank, wheels or otherwise .

Idk. I just looked at the dyno videos for the ECU upgrade and secondary cat bypass pipes from fabspeed motorsports on youtube. They did add roughly 17-20HP with the exhaust and ECU as well as a BMC Air Filter. Was guessing a Evo or Agency Power Cold Air Intake would add 2-3HP more than a BMC performance Air filter so that is how I reached 20-25HP.

As Fabspeed advertises.
8HP and torque for bypass pipes
10-12 HP for ECU Upgrade
Up to 5HP on BMC Filter(my guess is more like 1-2)

[Johnny Danger]

Originally Posted by ProjectM96

Idk. I just looked at the dyno videos for the ECU upgrade and secondary cat bypass pipes from fabspeed motorsports on youtube. They did add roughly 17-20HP with the exhaust and ECU as well as a BMC Air Filter. Was guessing a Evo or Agency Power Cold Air Intake would add 2-3HP more than a BMC performance Air filter so that is how I reached 20-25HP.

As Fabspeed advertises.
8HP and torque for bypass pipes
10-12 HP for ECU Upgrade
Up to 5HP on BMC Filter(my guess is more like 1-2)

No offensive, but Fabspeed would love all of us to believe that their by-pass pipes and ecu program accomplishes those figures. Realistically, however, once a person has completed his or her upgrades, a good ecu tune more or less "tweaks" the air/fuel parameters . In turn, this can create better engine response and fuel efficiency . The actual gain is hp is negligible . As far as the effectiveness of bypass pipes are concerned, one can shed a good deal of weight from the vehicle, as well as open up exhaust flow which is caused by the restrictive nature of oem secondary cats. Again, this equates into a very little actual hp gain . It's probably the drop in BMC filter that gives things a slight bump . LOL !

[ProjectM96]

Is BMC really that good? I hear lots of good things about it. Much better than a K&N filter, right?

[Overdrive]

^^^Note: Johnny is clearly stating that he is using the EVO intake purely for sound enhancement and not a performance enhancement for the car. One should always take the manufacturer's numbers with a grain of salt until you see it for yourself.

I would say, just my personal and not nearly expert opinion, that the most effective modifications are also some of the most expensive, and aren't going to net a ton of power. Jake Raby has developed some great improvements that both bulletproof the engine and increase its performance, but you're looking at a really high cost for it, at which point you're going to want to keep that car and get your money's worth. From what I see and read, Jake's done some incredible things, and for them you'll pay an equivalent price.

If you're not that attached to the car then for the same potential $20,000 you could be spending, you might as well combine that with a trade of your Boxster and knock out 1/2-2/3 of the cost on a new Corvette Grand Sport. It's no Porsche, but it's also not going to take much to pull an easy 50 more horses out of the thing when it already has more than double the Boxster's grunt. That was just for the sake of example.

What I didn't mention in my first post in this thread is where that plumbing change idea came from. Pedro's garage, where Pedro has come up with some great and pretty cost effective mods for the car, is another good place to look. Again, you're not going to get gobs of horsepower, maybe you'll get 20, but you'll get as much out of those horses that you do have as you possibly can when you start chipping away at Porsche's compromises. Have a look if you haven't already.
www.pedrosgarage.com
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