I don't go to Kal tire unless it would be an emergency, so many other good shops out there. Some of there policies are outrageous as well as pricing. How are the new skins?

 

They're in better condition than I expected. The guy has 3, he sent me the two better ones and kept one that has been previously repaired for his spare. But... something is wrong, either with the mounting, the 3 piece rim or the stem. I was losing air on the old tire and still losing air now. Kind of surprised that Kal Tire did not even bother to check for leak on a $60/tire mounting job. I lost 7 psi, pumped air and down by 4 psi after a 20 km drive from the north to our house in the west.

 

I sure hope for $120.00 they replaced the valve stems... I would think with that rapid of air loss that you have a leak in your three piece wheel somewhere (quite common on some wheels), looks like a trip back to Kal Tire and give em hell. Keep us posted...

 

another wheel related question:

what other tire options do I have if I want to keep my current rims but want to go with tires with more sidewall?

My Modulare M7's are 22 x 10 in the front and 22 x 11.50 in the rear.

It looks like a 295/40/R22 for the front are not that hard to find, but I have no idea what other tire width are suitable for the 11.5 rims. The Pirelli Asimmetrico 335/25/22 are the only 335 series I could google, but I am willing to go 325 or 315 if they will fit properly and available in the aspect ratio that I want.

 

just got a pair of H&R DRA 30mm spacers for the rears of my winter setup (18" Turbo II) and planning to install on the weekend.

quick question because the install instruction is not quite clear on this.

for the H&R DRA type, the spacers came with bolts to attach the spacers into the wheel hub, install instruction says tighten to vehicle spec (120 ft lbs)..

for the standard bolts to attach the wheel to the spacer, it only said make sure to do minimum number of turn, ie

12 x 1.5 = 6.5 turns = approx 10 mm of load bearing shaft length
14 x 1.5 = 7.5 turns = approx 11 mm of load bearing shaft length

here's how the spacers look


is it safe just to just torque it to 120 ft lbs if you have a torque wrench?

also read on other forums to apply copper grease between the spacer and the hub so that it will easily come off when it's time to remove the spacer - will ordinary lithium grease do for this purpose?

and lastly, I've read polarizing comments regarding the use of thread anti-seize, some suggested this is a must when bolting the spacer to the hub and they could be a pain to remove after a while if installed without anti-seize or similar stuff. Others warned against them and they could screw up the torque rating and eventually the bolt could come lose. Can Thread Lock be used (packaging says it will prevent bolts from rusting, and bolts can be removed later with hand tools) for this application?

Tire Rack website suggested that if this anti-seize is used, make sure it is only on the threaded part, and nothing goes into the bolt seat as this could screw up the torque measurement.

I will probably remove the spacers in the spring when I switch back to my summer setup.

Inputs from the "experienced ones" will be appreciated. I am still a newbie when it comes to car stuff as I used to spend all disposable income in audio and aqua hobby ... but I am learnin'...

 

I've always used an anti-seize compound on wheels/hubs to aid in future removal but have never tried lithium grease. Just brush a thin coat on the mating surfaces and you'll be glad you did come removal time. The anti-seize is made for applications just like this, does the job well, and is inexpensive so I'd recommend sticking (no pun intended) with that. Any auto or hardware store will have it for a few bucks. However, I would NOT recommend using it on any spacer bolts or wheel bolts at all - not even the threads as it will likely affect your torque settings. The problem at removal time is not getting the bolts out, it's getting the spacer away from the hub or getting the wheel away from the spacer. I'd also advise against using thread lock on wheel/spacer bolts as well. Yes, you may be able to remove them in the future, but it could end up creating a significant removal problem and probably a few new words for your vocabulary...

BTW - do you mind sharing what you went with for your cold air intake and the filter for your air suspension?

 

Hi Jay,

I went with a foam type filter (RAM Filter) that I bought from ebay a while ago. Some people prefer it over the other more popular brands because it is not oiled, the criticism I've read about it is it does not come with any support and can move around when installed. We just fabricated a simple plate made of .040" aluminum and fastened the elbow to the plate and bolted to the car at the bottom when the factory box used to be. The plate also serve as a barrier for the hot air from the engine bay, much like the Fabspeed design. I am happy with the result, as the install is quite stable. I just added a small K&N air filter to the air suspension breather hose. This and the Leistung resonated cat delete pipes made the GTS more enjoyable. The only items I have left on my to do are the ECU tune and maybe a sprint booster. Planning to do this after Porsche warranty expire. I found a tuner who does ECU tune specifically vehicles in our region (2300 ft above sea level).

Here's the pic before the K&N filter was installed.

 

^^^ I like those filters!

 

That's the first I've heard of an un-oiled foam filter..

And mounted in the engine compartment sorta makes it a hot-air filter eh? The stock ones have two things going for them: (1) they get outside ambient air - which is almost always cooler then engine compartment air (2) they get a ram-air effect at speed - pushing more air into the filter housing.

I can't imagine the stock filters being restrictive, since there are two of them about twice the size of the single filter my BMW M-engine uses for 2/3rds the displacement (and on that engine it's been shown the filter is not the restrictive element in the air-pump called the engine..)

 

the stock boxes..pull from under a little part that's in the front bumper, above the radiator shroud, so I cant see a huge ram air affect going on there. As for ambient air temp...well maybe a little being that air is being pulled from there versus the from fender area. Someone should get some intake air temps at the fender location to see what they are...My multimeter may be able to do this..I'll check.

 

Don, I realize that you know a lot more about vehicles than I (next to none ) do, but looking at the factory box inlet and comparing it to the aftermarket versions gave me the impression that the aftermarket version will allow a freer air movement. The box and filter might be big, but the inlet opening is not that big. For sure Porsche designed it to be more than enough, but based in my experience, replacing it did not hurt. I could be wrong as we did it the same time we did the cat delete - but a lot of people who have done this before attest positive result. We live in one of the coldest regions of the world, so our ambient air is not going to an issue. The location of the aftermarket intake for sure still draw a lot of air from the front fender area, especially when you are moving forward (which I do most of the time)

 

I'll just repeat a comment a mechanic friend often says.. (usually about BMW engineers..) "Do you think the engineers leave 10-15HP laying on the table for anyone with a garage shop to grab?"

What he means by that is - the engineers of German autos usually are actually pretty good at optimizing the performance of the cars they make. I haven't done any dyno tests on Porsches.. but I've done LOTS on BMW motorcycles and some on BMW cars.

In no case have I found an overall performance improvement with simple things like changing the type of air filter. I have observed on occasion, a minor change in high RPM power - at the expense of lower RPM power/torque - usually with changes to the exhaust. The thing is - unless you're racing the car all the time - that extra power at near max RPM does you no good, and you frequently sacrifice driveability at real world RPMs.

The worst case I saw was a "performance" exhaust for a BMW bike. It did give about 2HP at max RPM (in addition to the usual ~70HP) - at the same time, it took away a full 1/3rd of the HP in the midrange RPMs - where the bike is actually used. It was so bad (and it wasn't a fluke - I tested about 4 of these systems) that the manufacturer of the exhaust quietly withdrew it from the market.

Most German engines are pretty well optimized to how we drive them every day. Things like exhaust and intakes are cheap to get right vs wrong (the incremental cost is almost nothing in manufacturing) - so it's hard to really improve on the factory setup. The engineers at the factory have decades of experience to draw on and the most advanced test facilities. There are some restrictions they live with such as noise levels, but despite that, they really do a pretty good job.

What actually makes more HP is bigger/more valves, or higher RPMs, or simply a bigger engine (or the sin of forced induction.. - supercharging or turbos )

I rather suspect that if you were to do back to back dyno runs, same vehicle, same dyno, same day - on the stock intake and the replacement intake, you'll find you lose power with the replacement. That's if the dyno is run correctly, and is setup with a fan large enough to simulate the ram-air effect you get moving a car through the air.

That's just my guess.. based on seeing cone shaped intakes drawing air from right above a very hot exhaust manifold (cold air is good - it is denser and contains more oxygen, which results in more power..) And as I mentioned - I'm surprised these are dry foam intakes. I've never seen a dry foam filter, and wonder just how effectively it actually removes dirt and dust from the airstream.

FWIW - the BMW Inline 6 S54 M engine makes ~340HP (same as the Cayenne S) out of 3.2 liters (vs 4.5 on the S..) and uses a filter about half the size of ONE of the TWO filters on the Cayenne S. And in lots of dyno runs - it's been shown the factory paper filter is a restriction or causing any loss of power. Cones, panels, foamed, cloth, they've all been tried, and there simply wasn't any more HP produced.. which is why I can't see the factory Cayenne filters being a restrictive element.

YMMV, as may your power..

Best,

 

YES!

I think when a car is designed they define a package. Size, capacity, and target engine output, etc.

So they set out with a defined output target, not to extract every last pony from a design. They want to keep it "conservative" for what the engine "could" do and to enhance the long term reliability of the car.




I would agree that OEMs have more time and research into the performance than most aftermarket companies. And, that changing only one part of a system usually has little effect on its own.

However, OEMs are also very restricted by noise and emissions standards. Their goal is to achieve a specific hp range with specific expectations of reliability and very specific targets for noise and emissions.



Knowing several OEM engineers I totally disagree with this. The engineers are not in charge of the ultimate product in production, the accountants are. Companies penny pinch the crap out of things. If they can save a fraction of a penny on an item it may save millions of dollars of total production cost. If it costs the car 10hp, but was still within the original design targets, and saves a million bucks on production, they will do it. This is when we can go back in and add a $15 part and gain 10 hp on something.

The trick to this is that what worked on one car does not work on every car. Auto enthusiasts are know for simply trying to apply one solution to every car they buy.


Cold air intake is a great example. In one car the factory packaging may have had to sacrifice the ideal intake spot to fit some other parameter. Might be a location where a cone would be ideal, the factory just can't do it for noise and emissions. But then people try that on every car and in many cases take air from a less than ideal spot.



Also consider from a product life cycle and marketing standpoint. If the manufacturer knows they can produce a 300 hp engine for the same cost as a 200hp engine, but research shows that the consumer will buy the 200hp version, this is where you start. Year one, 200 hp motor. When sales slow, you offer the 240hp version. Eventually working your way up to the 300hp version if you need to or charge a premium for it. Has very little to do with what the engineers can do, but more what the marketing department can do.

 

good posts guys! Good points from both sides....

I think some manufactures, ie. BMW seem to extract great power from their engines..for example, the E60 M5..I was actually looking at this car for a bit...and mods to. I was very surprised that not much power was being seen from aftermarket components, ie. CAI, exhaust, headers, etc. In fact some people were actually losing horsepower from adding certain mods. So it seemed BMW did a great job extracting and optimizing components of the engine to maximize it's power from the factory..which I think is great.

BUT then are the EVO's Supra's, etc., that gain 15 whp from an intake, 70 whp from a straight pipe and exhaust, 20+ or more whp from a good tune. All on stock motor components...so to say that the engineers would not leave some on the table is not accurate...they left ALOT on the table.

I see new Z06's picking up huge gains with just intake, headers and exhaust and tune...plenty left on the table...100+ whp.

I agree with the drive-ability argument...I've experienced it first hand myself..most cars are optimized for everyday driving. Adding some mods to some cars, maybe doesn't matter and perhaps makes drive-ability worse. For example, guys who complain about losing some low-end torque when putting an exhaust on their Cayenne S, which I've seen a few times just being here a few months.

I think in this case you have to consider what you're modding....Would I spend a lot of money b/c I think an intake and catback would gain me even a few HP and TQE on a Cayenne S...no. That's why I bought a Trubo! The money I do spend on mods will most likely not go unnoticed. In this case, for my CTT..I appreciate P-car engineers for leaving that power on the table so I can have fun adding it back and having fun while doing it!

 

Cole,

Interesting discussion. I will admit I don't have any dyno experience with modified Cayennes.. does anyone have legit dyno info? (And not from a manufacturer of modifications, it's way too easy to skew a dyno plot for fun and profit..)

It's possible Porsche is more conservative (it might explain why they have less then 400HP from 4.5L.. on a BMW that would be close to 450-500HP..)

When I see some legit dyno plots (same vehicle, same day, same dyno & operators, A-B comparisons by "uninterested" parties..) I'll happily retract what I said.

What doesn't change is - the intake on a Cayenne S appears more then adequate for the amount of air that engine is pumping through it. On a normally aspirated (AKA "NA") engine the airflow is restricted by the smallest opening in the path air takes through the engine. I would hazard a guess that the valves are the biggest restriction. If you look at the size of the intake and exhaust and then imagine the size of the valve opening, it becomes pretty obvious that this is where the bottleneck is. And that is a quite expensive thing to optimize (changes engine geometry, max-RPM, even parasitic loads due to high-lift cams..)

Maybe Porsche should consider hiring BMW engineers as consultants.. As noted, BMW seems awfully good at extracting more then 100HP/liter from many of their naturally aspirated engines. These engines and cars have to meet the same noise requirements and emissions requirements that Porsche does. In general, even the M series engines are fairly reliable and unless grossly overpowered via forced induction (some people make in excess of 600HP from the 3.2L S54 engine with aftermarket turbos and superchargers) they don't blow up all that often.

On BMW forums that I moderate - the most common reply when people ask how to get more power from their NA M3 engine is - LOTS of money and forced induction. You could and people have, spent thousands of dollars on intakes and exhaust, and removing catalytic converters - and end up with no more useable HP and no more area under the torque curve.

BMW doesn't leave anything on the table that is cheap to grab. Given the even higher profit margin Porsche has on their cars - I'm surprised they would, but guess ya never know..

Of course with forced induction, all bets are off - you can PUSH more air through a restriction, and that's what a turbo or SC does. To get more power - just push more air and feed it more fuel.. (until things start melting down.. ) It was true 45 years ago with a Judson supercharger on an MG engine.. and it's still true today.

HP/Weight in my garage (excluding vehicles in the driveway - BMW wagon and the Cayenne, and my snowblower): 7.1lbs/hp. Average 0-60 - 3.75 seconds. - That's an '01 M-Coupe and an '07 R1200R.. if we toss the snowblower in, it's simply awful..