S54 Powerband

[Ubermensch]

Originally Posted by Finnegan

Very good point here, and it makes me rethink my "cost/benefit" statement a bit. I haven't researched the stepped header + tune direction enough to comment. But if it give the S54 more of an S65-like charge to redline then that's a huge improvement. Not absolute power like you say, but rather more fun and enjoyment from the motor. So many folks (look over at M3 post) get caught up on absolute power numbers rather than looking at the "whole package" (power curve, feel).

One would be looking at over $3k for headers + tune however I'd love to improve the feel of the car, but definitely not willing to pay that much. I mean hell if you are going to go that far you might as well not and just go right up to the s/c (unless the headers will be a supporting mod for the s/c).

[graider]

so from your experience, the 996 gt3 engine is better than 997.1 and .2 gt3 engine? that's pretty interesting...996 gt3 pricing is pretty attractive right now.

Originally Posted by shift@red

Interesting comparo with the G tech. Are those real runs you did or just simultions?

The 911TT is a turbo motor, but compared to other turbo'd car out there it still pulls like a freight train in the high rpms...as opposed to BMWs where they fall flat on their faces after 5K rpms.
What you experienced in the GT3 has nothing to do with the motor, but more your experience level with the RR platform. The motor IS still one of the best high revving NA engines out there and has a powerband that I personally feel there are only a few cars in the world car match or beat, and all of them are much more expensive cars. The power in the 996 GT3 blew me away from the first time I spun it all the way out. The way it spins so freely and only seemingly exponentially pulling harder and harder (like a real race car) really was something special, and not matched but in a few other cars.
I have a friend who races in a GT3 and has learned to drive it well...and in doing so there really arent many cars that can keep up with him. He owns A LOT of high end cars, Porsches, BMWs, an R8, Ferrari's...and he will tell you the 996 GT3 motor is without a doubt easily one of the all time bests.

[mousitch]

Originally Posted by Ubermensch

One would be looking at over $3k for headers + tune however I'd love to improve the feel of the car, but definitely not willing to pay that much. I mean hell if you are going to go that far you might as well not and just go right up to the s/c (unless the headers will be a supporting mod for the s/c).

Wait..Maybe I can change your mind... Plus it's a supporting mod (hint hint)

[Ubermensch]

Originally Posted by mousitch

Wait..Maybe I can change your mind... Plus it's a supporting mod (hint hint)

Hehe we shall see

[pokeybritches]

The S54 vs S65 link didn't work for me, so sorry if I repeat anything that's written there.

I noticed the S54 felt strained in the upper RPM when I first drove a Z4M. It didn't feel that much faster than my 3.0i unless I really wound it up to red line. The reason the S54 feels strained is because it IS strained. I'd rather not reference the initial rod bearing failures, but I will say this: look at the bore vs. stroke in it and compare it to the S65.

In the little bit I've learned about engine development I've found larger bore = more hp, longer stroke = more torque. A shorter stroke with the same displacement yields higher rpm potential (due to a lower piston speed), and hp = torque x rpm / 5252. An under-squared engine (stroke > bore) will usually have more low-end torque and better fuel efficiency. This is obviously not always true, but I think it's a good generalization. The S54 sacrificed some top end power to have the torque that it does, and to have a shorter block. A larger bore and shorter stroke probably would have yielded more hp at the cost of torque and handling (that would be a LONG block of iron). Once BMW went with a V-engine, they didn't have to worry quite as much about having a long block of iron hanging over the front wheels, and were able to increase the bore and shorten the stroke.

This was somewhat confirmed by watching a Dinan video about the development of their stroker kit for the M3/M5/M6. Dinan says BMW was conservative in their release of the S65 and S85, and left a lot on the table.

[Shipkiller]

Sorry about the link. My web server has a hard failure somewhere and I am attempting to figure out what is wrong. It is not the priority right now. Finding a good set of tires that meets my specs is....

[G80indy]

huh! my M wants to just run. And I owned a seriously modded DSM, so I know about FI. I guess what I love so much about the NA S54 is its willingness to go. zero lag.

[Ubermensch]

Originally Posted by 330indy

I guess what I love so much about the NA S54 is its willingness to go. zero lag.

Willingness to go and zero lag would be the 8.3L V10 that was in my Viper