|
|
|
|
|
|
BMW Garage | BMW Meets | Register | Today's Posts | Search |
|
BMW 3-Series (E90 E92) Forum
>
Tunes blowing the engine?
|
|
07-11-2011, 03:28 PM | #23 | |
First Lieutenant
8
Rep 330
Posts |
Quote:
Does this MHI data not apply to our turbos for some reason? Aren't you just supposed to look at the center of the efficiency islands and calculate the boost delta from atmospheric? Not trying to be a douche, just trying to learn. |
|
Appreciate
0
|
07-11-2011, 03:32 PM | #24 | |
Banned
70
Rep 2,197
Posts |
Quote:
Would someone please point to a DIY or good source on how to read turbo effeciency chart |
|
Appreciate
0
|
07-11-2011, 04:06 PM | #26 |
Colonel
62
Rep 2,013
Posts |
I dont know how to read the graph either, but Im just saying that in my opinion if you stay below 15-16 pdi you will never have a problem.
Wwn if you occasionaly crank it up a bit more on race gas it isnt tol bad, but boost needs to drop down a lot past 6000rpm to avoid overspool. |
Appreciate
0
|
07-11-2011, 05:01 PM | #27 |
Some say...
239
Rep 4,296
Posts
Drives: Fresh
Join Date: Mar 2010
Location: Baton Rouge n NOLA
|
this
__________________
I have exhaust and an intake... |
Appreciate
0
|
07-11-2011, 06:28 PM | #29 |
Colonel
62
Rep 2,013
Posts |
The motor is indestructable? Yes
But how about the turbos? Far from it At my dealer, I know of 3 people who have blown turbos due to tunes and 1 other guy who melted the internals of his cats These cars are very strong, but never run too mich boost without the right gas and supporting mods |
Appreciate
0
|
07-11-2011, 06:43 PM | #30 |
Major General
130
Rep 5,040
Posts |
yes! see this thread:
http://www.e90post.com/forums/showthread.php?t=556860 |
Appreciate
0
|
07-11-2011, 06:45 PM | #31 | |
3441
Rep 79,211
Posts
Drives: C6 Z06, 09 335i, 10 335xi
Join Date: Dec 2008
Location: www.TopGearSolutions.com
|
Quote:
|
|
Appreciate
0
|
07-11-2011, 06:50 PM | #32 |
Colonel
60
Rep 2,014
Posts |
|
Appreciate
0
|
07-11-2011, 07:29 PM | #34 |
Lieutenant
45
Rep 473
Posts |
So from what I got from this thread is its safe to mod these cars as long as you take the following precautions... basically this is just like every other car I've modded. lol For some reason people made it seem like as soon as you touched it the car was done for. I guess i didn't do as much research as I thought I did.
|
Appreciate
0
|
07-11-2011, 09:30 PM | #35 |
Banned
33
Rep 1,034
Posts |
I think, less than 1% of tuned 335's suffer severe engine damage, is an accurate statistic.
|
Appreciate
0
|
07-11-2011, 09:38 PM | #36 | |
Major
62
Rep 1,476
Posts |
Quote:
for reference 1 bar = 14.7 psi |
|
Appreciate
0
|
07-11-2011, 09:47 PM | #37 |
Major General
545
Rep 7,705
Posts |
PROceed tune'd for 53000 miles. I just hit 454 rwhp, 466 rwtq with newest PROceed map & PWM meth kit with Full bolt on mods. Car is running better than ever. No tune on N54 is like eating burger without fries & coke.
|
Appreciate
0
|
07-11-2011, 09:58 PM | #38 |
Lieutenant
17
Rep 480
Posts |
I run procede all the time with 0 problem (only some bugs from the map). If you're not set it to some crazy boost level with stock turbo you will be ok!
__________________
2003 E60 530i - PSS9 Coilover/M Kit/BBS GT-RS 19" wheels - retired
2006 E91 335i - Procede V5/Forge DV & FMIC/Bastuck quad exhaust/P1 Steering Wheel/Sachs Coilover/M kit/19" RS wheels - retired 2011 F10 535i - Stock |
Appreciate
0
|
07-11-2011, 10:18 PM | #39 | |
Lieutenant Colonel
65
Rep 1,708
Posts |
Quote:
Pressure y and flow x. pressure is ratio of absolute to baro / flow can be volume or mass flow (includes air density or not). Efficiency and compressor rpm are referenced. The very left side is surge line... too much pressure versus flow (stalled compressor) or right side choke point... not enough compressor air volume to meet pressure ratio (100% WGDC). For "safe boost" it depends on the volume of air required and this increases with rpm of course. So you would basically plot a straight line at your target boost pressure. Efficiency will be greatest in the mid-range and then start declining as your flow increases due to rpm. Flow is NOT linear with rpm though as VE (torque) drops with rpm. We need more threads like this on e90post. No one answered my VANOS questions |
|
Appreciate
0
|
07-11-2011, 10:30 PM | #40 | |
Banned
127
Rep 6,773
Posts |
Quote:
|
|
Appreciate
0
|
07-12-2011, 03:58 PM | #42 |
First Lieutenant
8
Rep 330
Posts |
If you know something please chime in. All the information I have is from the MHI data.
Take the most efficient island, find the max total pressure, subtract 1 bar(14.7 psi, thanks Dr Dirt). That should give the maximum boost for the most efficient island under ideal flow rates. Am I doing this wrong? Where do these turbos start to become inefficient? Why? We need a graph which shows efficiency vs RPM, since we don't know what our flow rates are at different RPMs, or what boost levels are most efficient at the flow rates we produce.(thanks Joshboody). 11-12 psi seems reasonable to me considering stock boost and MHI data. People are running much more boost than this (myself included), but that doesn't mean we aren't out of the efficiency range on these tiny little turbos. As I said before, not trying to be a douche just trying to learn. Thanks. |
Appreciate
0
|
07-12-2011, 09:12 PM | #43 |
Lieutenant Colonel
65
Rep 1,708
Posts |
You can calculate general air volume / mass for x horsepower
- use the dyno thread for horsepower reference (at the crank). - VE will follow the torque curve - VE will increase with boost - Mass air flow is directly proportional to hp - And we know the boost people are running for certain hp levels. Should provide a fairly accurate plot. I’ve seen this plotted by Cobb, but they assumed a steady VE using MAF (not actual, calculated) logged by the DME. I would start with VE of 110% at peak torque for FBO… but I really don’t know. Much of this info should be in the turbo sticky, but haven’t looked through it all. |
Appreciate
0
|
Bookmarks |
|
|