E53 Headders/ Gears?

[Daddy_Warbucks]

Here is what I got back from KMS for the gear change in the X5 for both diffs:

We can sell you front and rear final drives with 4.10 ratio for $2745 total, plus $1600 core charge. The $1600 would be refunded upon return of your original final drives.

This replaces the 3.91 gear drive that is currently standard in the 4.6si.

nb. This is equivalent to a 5% HP boost, or (for me) 26 HP.

[statdoc]

Originally Posted by Daddy_Warbucks

. The math can be a bit much if you havn't taken a college thermodynamics class: http://www.vortechsuperchargers.com/...oler_paper.pdf

Thanks for the link, and the warning. I am sure there are at least a few of us here who could struggle through it. If not, we can ask for help.

[Daddy_Warbucks]

Indeed, G-Power does make a custom set of headers for the X5 4.6si (actually they fit certain models of the 4.4, 4.6, and 4.8). The part number is 560.1521.86 and they sell for $3,364 euro plus $195 euro shipping. Located at www.g-power.de . I've seen pictures... they look pretty good.

What I do not know is if they fit right up to the US catalytic converter. I have a note in to them to understand this (nb this is actually of no consequence to me as I can have custom connection piping and/or modifications to the existing system to basically fit anything at a reasonable price. The average guy, though, will want a simple, bolt-up solution... and I'd like the answer to that question).

[Daddy_Warbucks]

I ordered a set of 4.56 gears for my X5... exchange basis, and they should be here by next Friday. I ordered a set of headers from germany through a friend that lives there. THey were very expensive, but they are bolt-up too, and contain the entire set of pipes all the way to the mufflers.

[bigfish]

Thanks for the info, let me know how it feels after the new gears and headers. I just got back from the track and I could have used some additional low end power!

bigfish

PS. How much did the gears run you??

[Daddy_Warbucks]

The gears were $2,745 total plus a $1,600 refundable core charge (eg write a $4,345 check, they send you a set of differentials, you swap them out and send them your differentials, they send you $1,600). That includes shipping one way (to you), so you have to pay the shipping back to get your refund. They weigh about 100 pounds each packaged. The trouble with new gears for the X5 appears to be the front differential. They have a pretty wide variety for the rear, but only currently make a few ratios for the front.

The headers were $3,700 plus $180 for shipping. I've seen them on an X5 already (a custom G-power) and they do sound pretty good.

I'm getting to the end of mods for this thing... I'm going to investigate the intercooler next... I don't know about you, but I notice a good sized increase in HP when the temperature is 60F instead of 80F... even though the charts would tell you that at such a low boost, the heating effect is small. The numbers done lie though... so I think I'll have the British folks make me one... and then install a boost management system (instead of the Dinan). A wet NOS system might be fun too, but I don't want to "over stress" the motor...so will probably shelve that.

I did hear that multiple German conpanies make stall converters with stall speeds in the 1800-2000 RPM range... which would be a dramatic change from the current 1000 (or abouts). 3000 stall would be exactly perfect (which they do make), because the supercharger is just "engaging"... but it also means you really can't tow anything... and its a bit more difficult to handle in traffic (lurch effect!!!).

More as the project unfolds.

[Daddy_Warbucks]

Two weeks ago, I got the new set of differentials from KMS in Ohio. I opted for the limited slip version of the rear differential because I noticed a little tire slippage upon launch... and we just can't have that! The deepest ratio I could get was 4:11... because of the front differential gear availability (rear gears could go to much higher ratios). It took a full 9 hours to install the differentials... the back took about 4 hours, and the front 5 hours.

You wouldn't think a small gear change would make that big of a difference... but it does. The Supercharger gets into the sweet spot (3000-7500 rpm) much faster now. With the new limited slip rear... the thing really hooks up great too.

The custom stainless steel headers and exhaust system ship from G-power in germany on March 5th. I need to pick them up at ORD in Chicago. I will get them on and report as soon as I can.

I did some research, and the euro 3.0 liter diesel uses a intercooler that fits up under the front of all X5 chassis. It looks like the tubes might almost fit too. I will investigate the project this summer when it warms up. The cooler is about $350, and is a genuine BMW part (check out realoem.com if you are interested).

Of course I have not made it to the ract track yet, but the races I've had on the street tell me that the car is in the very low 13 second range.

[bigfish]

DWB,

Thanks for the update. What did the gears, plus install run? Did you have to exchange your stock gears or did you keep them?

I have Dinan working on my 03 4.6is S3, they are reducing the SC pulley wheel diameter to increase boost. They were very reluctant to do this. They say that the engine is strong enough to handle approx 1 to 1.5lbs of additional boost. However the weakest link seems to be the transmission. They believe with the additional HP and torque the tranny with be the first victim.

I should have my car back next week, I will keep you posted on gains. My next mods will be an inter-cooler (technically it's an methanol and water after-cooler) and boost gauge.

This past summer I went to a event held by Los Angeles Chapter of BMWCCA at California Speedway in Fontana. It was two day clinic that gave equal parts of classroom driving instruction and track time. Each participant was paired with an SCCA driving instructor and we got to take our vehicles out and drive them right to the edge. When the DSC is off and the tires are hot, you can get the X5 to allot more then I thought. You are connected to the in-car instructor via a two way radio in your helmet (really cool) they are constantly giving you input, feedback and instruction. These guys and one girl really know what a car can do!

I talked my instructor into taking me in his car for a few hot laps, I was holding onto the harness the whole time, repeating shit, shit, shit as we went down from the banked turn on to the apron at 130mph and that was at least 50mph faster then we had gone in the X. It was worth every penny and I am planning on doing it again this year!

I was one of two X5's in a total of around 90 other cars, mostly M3's & M5's also a couple of P-cars (GT3 R's). It was a good time, the other X5 had suspension problems and had to retire at the end of the first day. But we earned a little respect from the M drivers over the weekend.

Long story short (to late for that) I hooked up with a couple of guys who custom fabricated their own inter-coolers and were running boost gauges. I am going to work them and also another local shop to see what we can come up with for the supercharged X5!


Bigfish

[Rev Z-Man]

Any of these companies make headers for the I6-3.0L?

[Daddy_Warbucks]

Rev Z-man: Sorry no headers for the 3.0L machine. I kept my eyes open when looking fo the 4.6L because I knew someone would ask. I'm guessing, though, that G-Power would make a custom set. They seem to do it all, including transplanting a 700hp M5 motor into the X5 (GULP!).

Bigfish: Very cool on the intercooler. Please let me know how that goes because I'm interested too. There are several companies that make custom intercoolers... and in fact...the one off the diesel X5 is supposed to fit perfectly (eg the mounting is already on the X5... just below the radiator). You can see this thing with part number on the diesel version in OEMPARTS.COM

As for your questions about the gears... The whole gear install cost about $800. The rear I could have easily done myself, but the front is pretty complicated because the drivers side half-shaft goes through the front differential... and the cross member WITH the motor mounts must be removed to install the front differential. That involves supporting the motor from above with a gizmo that spans the motor compartment and sits on the inside of the fenders under the hood. I could have probably made something to do the same thing, but I was traveling a lot in that time frame and needed my vehicle in one piece. KMS sends you whole new differentials, and you send them yours as cores. MAKE NO MISTAKE... the extra low gearing makes the supercharger get into that sweet spot at 3000+ RPM faster... and we all know what that means!

I need to call Dinan and get them to tune the transmission software a little. Two things I don't like: The transmission shifts a little too slow now (I can get the rev limiter to kick in sometimes...but rare...because it needs to shift eariler in the RPM range), and the transmission needs to up shift when I let off from a full power launch.

I made some Delrin Guibos (spelling?) to replace the rubber ones. I can twist the rubber ones off too easily.

The exhaust system showed up about 4 weeks ago... but I have not had time to install it (I've been working on my sons Merc... he needs it for school). WOW! what a nice set of pipes. The headers, the first resonator, and the two mufflers are all bolt up stuff. The new catalytic converters are a different story. They just give you the (much improved... much shorter) cats... and you must pull off the old cats (collector of the header to the first resonator) and have the piping fabricated and the catalytic converters welded into this piping. I suspect this was done to get around some sort of regulation... I need to have a couple of weeks when I can just take the whole exhaust system off, have the new cat pipes made, and reassemble. Right now isnt that time... but I will have pictures.

I'd be very interested in what Dinan did for that new pulley. Can you measure the diameter? I'd be very interested... I can get one locally. I, too, am interested in a boost gauge... and have looked at some of the add-on graphic controllers for the Japanese cars... thinking I would just use the recording and reporting functions. I really like the Apexi AVC-R, the Greddy Profec E-01, and HKS EVC-5 because of their graphics. No one can give me a straight answer on using one with a BMW... so I may just have to buy the one I like best and experiment.

I recently installed the SMG steering wheel with the shift paddles and love that little mod.

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2003 BMW Silver M5 W/ Deep gears, Exhaust, Software.
2002 BMW X5 4.6i W/ G-Power headers and SS exhaust, Throtte Body, Super Charger, KMS gears, M3 SMG steering wheel.
S3 Software, black-out chrome on silver.
2000 Yamaha White Road Star Anniversary Full Dress #322
1999 BMW 528i
1990 Mercedes 300E
1989 BMW 325i
1978 Kawasaki 650 Street Racer