S65 Motor Limitations

[xander_g]

Hey,

Before everyone jumps in and tells me to search, I did and could not find a definitive answer(or one simple enough for me to understand).


What are the limitations of the s65 motor while keeping it NA?

I've read about different stroker builds (alekshop, dinan, rd sport) online and all of them are making numbers that are in my humble opinion, in the same ballpark.

Also, there are shops making race engines (kms, vf) but I am guessing is that those would not be ideal street applications for a dd car.

Is it not possible to build an s65 motor that could put down 600+ whp?

I understand that if one throws enough money at something, results will eventually follow.

I apologize if this topic has been beaten to death already, but If someone would be kind enough to provide some insight, it would be greatly appreciated.

[R3dliner]

I don't think that's possible. FBO will give you about 400whp. Even with a stroker kit with schrick cams, etc, I think 600whp might be a long shot but what do I know lol

[doogee]

Originally Posted by xander_g

Hey,

Before everyone jumps in and tells me to search, I did and could not find a definitive answer(or one simple enough for me to understand).


What are the limitations of the s65 motor while keeping it NA?

I've read about different stroker builds (alekshop, dinan, rd sport) online and all of them are making numbers that are in my humble opinion, in the same ballpark.

Also, there are shops making race engines (kms, vf) but I am guessing is that those would not be ideal street applications for a dd car.

Is it not possible to build an s65 motor that could put down 600+ whp?

I understand that if one throws enough money at something, results will eventually follow.

I apologize if this topic has been beaten to death already, but If someone would be kind enough to provide some insight, it would be greatly appreciated.

175hp per liter? Not happening. You need FI. You're talking NA power that the 675LT makes Turbo'd.

[xander_g]

133.3333 if it's stroked to 4.5

I get where you're going with this....

What would you say is an optimistic prognosis then?

[doogee]

Originally Posted by xander_g

133.3333 if it's stroked to 4.5

I get where you're going with this....

What would you say is an optimistic prognosis then?

From my math I'm getting 155hp/L with a 4.5L. You said 600whp no?

Is it being used for the street or racing?

[xander_g]

Sorry, math isn't my forte.

Street.

[BrewRifle]

I'd slap a 650 kit on and call it a day or go crazy and get a 4.4/4.6 stroker and slap a 650 on it =)

[xander_g]

Originally Posted by BrewRifle

get a 4.4/4.6 stroker and slap a 650 on it =)

lol those ambulances will have no chance

[BrewRifle]

Originally Posted by xander_g

lol those ambulances will have no chance

Not to mention 99.99% of what's on the street (I mean track )

[pbonsalb]

You won't get a streetable naturally aspirated S65 to make 600 rwhp even if bored and stroked to 4.6L.

Maybe build a lower compression motor and twin turbo it. Gintani sells a twin turbo kit. The Audi 4.0L V8 twin turbos make great power modded -- 600 rwhp is possible.

[xander_g]

So, where do you think the limit is on these engines whp-wise if kept na?

[BrewRifle]

580HP/390TQ is the highest I've seen from a club racing 4.6 engine - http://www.m3post.com/forums/showthread.php?t=1047750

[M3 Number 86]

lol racing engines in a street car. you plan to rebuild/maintenance after every "race"?

[tony093]

Originally Posted by pbonsalb

You won't get a streetable naturally aspirated S65 to make 600 rwhp even if bored and stroked to 4.6L.

Maybe build a lower compression motor and twin turbo it. Gintani sells a twin turbo kit. The Audi 4.0L V8 twin turbos make great power modded -- 600 rwhp is possible.

Does the V8 turbo Audi have an aluminum block?

[FogCityM3]

http://www.kmsracingengines.com/bmw-v8-s65-600hp.html

if you do a race engine; more bhp possible with higher rpm

[pbonsalb]

Originally Posted by tony093

Does the V8 turbo Audi have an aluminum block?

One guy on the forums with a stock block S65 and Gintani twin turbo is making over 600 rwhp. Not sure what audi, bmw, Mercedes are using for block material for their 4-4.4L twin turbo but I think at least some of those are aluminum.

[pbonsalb]

Originally Posted by BrewRifle

580HP/390TQ is the highest I've seen from a club racing 4.6 engine - http://www.m3post.com/forums/showthread.php?t=1047750

Dinan rates at the crank, so that is about 500 rwhp. But the Dinan motors (and other strokers) don't seem to put down the power claimed when tested on an independent dyno so I am not so sure about that possible 500 rwhp.

[DSilk]

Can you get a noticeable increase in power by adding a stroker kit to raise displacement? Undoubtedly the answer is "yes", but this begs the question as to what impact such a move will have on the longevity of the engine. Your money, your choice and your risk, but my opinion is that if you are that dissatisfied with the stock engine in your M3 perhaps you should be looking at a different car. I have a performance catless exhaust, underdrive pulleys, and a tune, and I remain very satisfied with the power and sound of my car. Am I going to outdrag a V8 Mustang or Camaro from a stoplight? Maybe yes, maybe no, but I don't care. I didn't buy the car to race it from stoplight to stoplight.

[xander_g]

Originally Posted by M3 Number 86

lol racing engines in a street car. you plan to rebuild/maintenance after every "race"?

Lol. Those engines need a rebuild every 5000 km, so a a rebuild every oil change.
That would solve the rod bearing issue at least

[xander_g]

Originally Posted by pbonsalb

Dinan rates at the crank, so that is about 500 rwhp. But the Dinan motors (and other strokers) don't seem to put down the power claimed when tested on an independent dyno so I am not so sure about that possible 500 rwhp.

There's a stroker shootout thread somewhere on this

[xander_g]

Originally Posted by DSilk

Can you get a noticeable increase in power by adding a stroker kit to raise displacement? Undoubtedly the answer is "yes", but this begs the question as to what impact such a move will have on the longevity of the engine. Your money, your choice and your risk, but my opinion is that if you are that dissatisfied with the stock engine in your M3 perhaps you should be looking at a different car. I have a performance catless exhaust, underdrive pulleys, and a tune, and I remain very satisfied with the power and sound of my car. Am I going to outdrag a V8 Mustang or Camaro from a stoplight? Maybe yes, maybe no, but I don't care. I didn't buy the car to race it from stoplight to stoplight.

I am absolutely satisfied with the stock engine. Like you said, I wasn't then I would absolutely buy something different.

I was just trying to find out why most of these cars go FI in order to make that kind of power.

The stroker motors have their cylinders bored in order to increase displacement thus resulting in a thinner cylinder wall which could potentially affect long term reliability, like you said.

This thread is a good read but is 4 years old
http://www.m3post.com/forums/showthread.php?t=849797

[pbonsalb]

I know.

I think another car might be best for the OP. A car that can make the desired 600 rwhp without much work. Like a Mercedes E63 AMG Biturbo, Audi S6/RS7, BMW M5, Cadillac CTS-V. I personally like AWD for that sort of power, because I would like to be able to put the power down as often as possible (my next car hopefully will be a 997.2TT or 991TT).