[obehave]

Maybe I am going above and beyond but follow me on this one...

When installing a larger TB onto the intake manifold, wouldn't one want to also increase the size of the intake manifold to match the TB? Do we know if the MINI IM is sized to the stock TB or is it larger? And, when the TB is installed, will the IM be bored out a little.

I only ask, we used to do this with our Civics. It just seemed like one went with the other. Maybe a bit overkill, but if/when I get mine, I will probably do the same. Doesn't pay to increase the TB without increase/matching the size of the intake manifold. I wonder if this is why people only say there is an increase in throttle response as opposed to an actual power increase??? Without making the IM bigger, there is still a "bottleneck" present!

Anyone else have any thoughts on this?

An increase in runner cross section will slow intake charge velocity. Also roots blower are dependent on resistance to generate boost. A larger volume will take longer to develop boost.
BUt honestly I don't know how much of a volume change it would take to make a difference. It would almost certainly move your power increase farther up the rev band.

Randy Webb is offfering Extrude Honed intake and IC runner pieces.
Link

I'll be doing that before I get a TB, if I even get a TB.
This very much depends on if the polished parts give anything below 3K rpm.
High rpm driving is not something I do.

 

[obehave]

I completely agree about the peak power! But don't you feel that the MINI could use a little more power on the high end? Meaning, after installing my CAI, I find that the car runs even better in the mid range, but the power climbing really seems to level off once you start to enter the higher rpm range! So I was wondering, since the midrange is so good, does it pay to work on the high end a little?

My 2¢....

That really depends on what you want.
Me personally. I'd like to see the increase between 2K and 5.5K rpms since that's where 98% of my driving is done. I've probably hit the rev limiter a dozen times in 2 1/2 years of ownership. A lot of this is because I have a good feel for shift points and I don't bang the limiter. The rest is because I don't do a lot of track time and I don't street race.

Improving the high end is pretty easy. Doing so without sacrificing low end is much less so.
From what I remember Extrude Hone can use different levels of abrasion. I need to check with Randy on how much material is removed during the process he has specified.

Surprising that you feel that your car tails off at high rpms. Most seem to feel it pulls well right up to the rev limiter.

Time for a high flow header/cat combo for you

 

[obehave]

Good point! Perhaps this is what I need! I am 'patiently' waiting for Milltek on this! I am waiting to hear back when their exhaust system for the '05 MY is ready. Perhaps this is it, I am sucking in a lot more now with no additional ability to get "it" out.

Then again, this may be 'my' problem! I come from DOHC VTEC motors where you build and build and build! Just need to get use to a new way of achieving the same speed!

What cat comes with that and what's the cell density?
From what eveyone has posted the headers are a high rpm improvement and that's about it.

 

[obehave]

Boy, I can't imagine someone saying that lighter aftermkt wheels and tires didn't make much difference. I suppose it depends how much lighter one goes, and how often they plant their foot Seriously, if one can lose 40 to 50 pounds of rotating mass, the giddy-up is greatly improved!

My 16" wheels are 10.75 lbs, and with the tires just over 20 pounds ea, I lost just over 10 pounds per corner, and with front aftermkt rotors, an additional 1.5 pounds, or almost 12 lbs per each drive wheel has been shed...

I just got married about a year ago, so I hear ya! Take care.

I got to talk with Randy a bit at a pulley party last weekend but forgot to ask him about how much material was removed.
I see my post there got zero response.
Definitely let me know what you find out. Right now I plan on getting the parts early next year. Must get christmas out of the way first
I'm with Tony though. Bigger TB, open up the manifold, run some headers and maybe cat back. You'll see more high end. There's a good chance you'll lose a little snap at low rpms though.

Now back on topic.
My first tire switch was just buying another set of used X-Lites and putting non runflats on them. Saved just short of 5 lbs per corner. That made a nice difference. Easily improved acceleration and handling. Next was the NZO Monzas (same tires) and another 2.5 lbs per corner saved. Again a noticeable improvement.
My SSR - Kumho auto-x combo is, if I remember right, is 6 lbs per corner lighter still. The tires are 205-50s and the car becomes very quick with them on. Some of the effect is the reduced diameter and some the weight.

I understand your desire to keep the runflats. I still have my originals.
Last time I had them on the car felt slow.
But, I really don't think that has any real impact on CooperSAZ's feeling that the high end pull thins out.