Quote:
Originally Posted by pokeybritches
3. There are threads about losing power with the Gruppe M and RPI combo. Do a search across all of the BMW forums.
5. I still don't understand why you want to upgrade the cooling system. The reason no aftermarket system exists is because there's no need for one. Get one if you start having cooling problems. An AA tune won't cause cooling problems.
8/265 = 0.030
You're looking at a 3% increase in power. Until you start to see temps rise, forget the cooling system. Not necessary.
The 3.0si doesn't even come with an oil temp gauge. If you want to upgrade something, get a gauge that tells you what your oil temp is. That way you can watch it stay in the middle and smile as you think about all the money you saved.
6. Price is way too high for the bumper.
7. Why do you need larger brakes? Are you reaching the thermal limits of the stock system? Start with different fluid and pads. If that doesn't solve your brake cooling issues, then and only then increase the mass of the rotors with a BBK. Larger brakes will actually hurt performance. More unsprung weight, more rotating inertia... the car won't react as quickly over bumps... and the system is no longer OEM so it can't be serviced at the dealership. Larger brakes WILL NOT decrease stopping distances. Your tires are your limit. The only time a BBK helps is on the track, when after repeated high speed stops, the rotors start to get red hot. A BBK rotor is more massive, and thus has a greater thermal capacity. "More massive" is a bad thing any other time except when at the track, after many hot laps. They hurt performance.
Basically they will be a fancy cosmetic mod with no real use, unless you plan on doing repeated (more than 10 in a row) 140 mph to 20 mph stops on the road back to back. Treat the brake "upgrade" like the cooling system upgrade - don't do it until you have a need for it. Otherwise it's a waste.
8. Tires - why would you want to go with a smaller diameter tire size?
9. Don't get the OEM cast wheels. They are overpriced and there are much better (lighter) options out there. If you have $13000 to throw down, get forged wheels. Forged wheels reduce unsprung weight and rotational inertia. Some say for every pound you reduce off your wheels, it's the performance equivalent of reducing 10 pounds off the car. If you get wheels that are 5 pounds lighter each than stock, your car will feel like it's lost 200 pounds. Personally I think that's a bit optimistic, but you will still see noticeable performance gains. DO get forged wheels. DO NOT get any BMW factory wheels.
10. If you're going through the trouble of painting your car, get the factory aero kit. I'd paint it carbon black to be unique, but your color choice is up to you.
11. Rather than reupholstering your seats, get Recaros and have the installer put the weight sensor for the side airbag in the passenger seat. Recaros can save you 80 pounds or more.
If I was going to throw down that kind of money, I would get a limited slip differential with higher gearing ($3k tops from Performance Gearing), lightweight Recaros (depends on how much you want to spend), forged wheels ($4k), max performance summer tires ($1k), AA tune (??), and save the rest. If necessary, get the aero kit and paint the car.
Why are you so against putting a limited slip differential in the back or changing the final drive? With all of the mods you've listed, a base 3.0si could out-accelerate and out-handle it with 3.64 LSD.
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Well, where to begin
.
So, I will have research the Gruppe M thing, but there are also comments that the aFe/RPi combo could cause power drops. The general opinion is that The Gruppe M/RPi combo usually causes a power increase. In any case I might just get the Gruppe M only. We will see.
I still have not decided anything on the cooling system and chip tune. So lets say that goes into the backup list for a while.
I also said that I was not sure about the bumper price. But As I explained in a earlier post, as my father OWNS the BMW dealership I reckon I can get the bumper at cost and have it fitted for free (have never paid for anything there anyway
).
I am not sure about larger breaks, BUT I would like to put some grooved or drilled disks on the car, purely for cosmetic purposes. I DO NOT have overheating issues with the breaks. I will look into the BMW Performance Brake Kit, IF it fits the car, again I will buy it at cost and have it installed for free (there's a money saver for you
).
Where did I say that I want to reduce my tire size? The 18 inch rims are a standard on the Z4 3.0si, at least here, and if you are referring to the 225/35 R 18 88 W Front tire size, I just feel that it is going to look more symmetrical, no other reason.
As for the rims, the BMW Performance rims are certainly lighter than the stock ones. As I already said, they will not cost a lot for me, and to tell you the truth I have never liked another brand's rims more than the BMW Performance rims.
The reason I want to pain the car another colour is to bright it up a little. Black is bit of a sad colour for me, and until recently, at least in Bulgaria, black was the base colour for all of the new BMWs. So as you can imagine there are a lot of black BMWs and I want to get out of that category.
I do NOT want to change the seats, just to remove the red from them and from the car. I kill for electric seats and I am not going to take them out now
. Furthermore, the only sport seat that I would consider putting in that car would be the BMW Performance seats, and that is IF they fit at all. And still this is just I MIGHT CONSIDER, I am not saying I will do it.
To tell you the truth the USD 13 000 that is currently the cost for the mods is almost exactly the discount I got when purchasing the car, so basically, if I had gone and bought it from another place, I would have spent that much on top of the USD 20 400 that I spet for the car and would have had any mods on it.
As for the LSD, I read somewhere that the stock diff on the automatic gearbox is something like 3.71. I know its not much over the MT, but I also read that some people were having problems with their replacement LSDs. I am not sure about this one, but will look further into it.