Ive been trying to read as much as I can about going to a larger bore throttle body on an R53. I haven't much mod wise with my engine. And it is down anyway waiting for the electric water pump mod this coming weekend.

But here is what I have so far.

- 15% pulley

- Goodyear JCW Gator belt

- NGK 54058 Tailor Magnetic Core Wires

- NGK BKR7EQUP

- Modified CAI

- Soon Electric Water Pump (means SC PTO free)

- OEM JCW 380cc Injectors

- One Ball Exhaust

- New O2 Sensors

I still have other mods like a header and other exhaust work, maybe jumping up to a 17% SC pulley. I'm trying to get as much dont without the need to pull the head for work, or going to larger injectors, or a cam, etc... then afterwards I can go get a tune to put it all together.

So is it going to be worth it to even consider going to a larger bore throttle body? 61-63mm with what I have now? Also any estimate of what power I might be putting out with said mods? thanks every one.

 

Most people just havn't had good luck with them, esp. the larger ones, like the 63mm you mentioned, I have the Dynan (59mm if I remember correctly), I like it, but if it ever failed I'd go back to stock instead of trying to replace it.

I played with both for a while, and while the Dynan seems to work very good w/ the Sprintex, with the M45 I found the upper RPM's to be slightly smoother, but there was a slight loss of torque down low, but again not enough of a benefit to warrant the cost at all, the only reason I even tried it was that I wanted to do "something" while I was still under warranty at the time.

 

Thanks bro... Thats what I needed to hear. The R53 MCS and JCW use the same throttle bodies. So maybe it stands to reason the forced induction doesnt need any more help getting air into the engine and an n/a engine would.

 

I didn't do this mod, so you can't either :P

Did you ever get the JCW software done for the 380s ?

 

No... there isnt a MINI dealer in this area. And Im not sure what they would charge or if they would give me a hard time about doing it.

 

Oh...they would charge you all right!!
But if they are willing... DO IT. Shorter term...more power...longer term...save you a few $$$ since you will not cook your cats.....and you should see more mpg too...good step if you are not going to go with a custom tune.

 

What do they usually charge for something like this?

 

as for a larger throttle body, the downsides and upsides have to do with valve sizing. There are several heuristics for sizing a valve for a process as you would like to have control, especially when it is a throttling valve. A larger valve will allow for less restriction up top, but will not be able to control flow rates as precisely down low for a given valve design. It works better on something like the sprintex as the sprintex needs that extra flow volume. The throttle body is actually why people have to modify the BPV when using the sprintex. It pulls so much air that the restriction of the throttle body actually causes enough of a vacuum after the TB to open the BPV.
As with lots of things in an engine, you can have low end power and control, or top end power. Choice is yours. Just pick which ever one fits your driving style and use of the car best!

 

Have heard anywhere from .5 to 1 hour labour....
But call first....some dealers have one particular person that known how to do it....and the practice does not seem to be universal....heck some dealers to pulley installs on gen1 cars....some are so far in the dark, they install an OEM belt on a car with a pulley...then wonder why it squeels......

 

I just need the JCW ECU flash. Everything is already on the car.

 

I was referring to the fact some newer dealers are boarderline incompetent with gen1 cars.....
Many techs just have not dealt with them in newer dealerships....and I have been told you need to "know your way around the BMW computer" to know how to upload a JCW tune on a non JCW car....but many dealers do it...some offer it...to help owners improve the drivability of their nodded cars....one tip...you say you have a 19%...the JCW pulley is about an 11% reduction....so you MIGHT run better... Thanks to the added fuel...but no guarantees... The JCW is MORE aggressive to get the 200-210 HP out of the same motor as the s (basicly)...so hopefully it still runs good with the extra timing.... Folks seem to do OK with a 17%...so you will be OK if I had to guess.

 

+1 - take a day off and travel to a dealer who knows what they are doing...

You are missing a whole lot by not having it done. Bump it to the top of your to do list. Best 100 bucks you will ever spend next to the SC pulley.

 

I will see who the nearest dealer is and give them a call and see what they say.

Well it looks like Seattle MINI is out. They want you to buy the MINI Works package for 6K before they will flash it. So they are a wash.

 

You are right, but you have got to be kidding me about the bpv opening. The inlet and throttle body combo are worst off then first imagined. So many improvements to the Sprintex design can be made..

Ron