|
|
|
|
|
|
BMW Garage | BMW Meets | Register | Today's Posts | Search |
|
BMW 3-Series (E90 E92) Forum
>
Hybrid Turbo options and comparisons
|
|
01-16-2016, 07:57 AM | #133 | |
Second Lieutenant
99
Rep 250
Posts |
Quote:
|
|
Appreciate
0
|
01-16-2016, 08:08 AM | #134 |
I like to party
45
Rep 126
Posts |
I found a fairly old(2003) turbo dodge forum discussion with a dyno comparison showing clipped vs unclipped. The 10 deg clip was performed in an attempt to gain top end power, ended up destroying the bottom end.
http://www.turbododge.com/forums/f4/...o-results.html |
Appreciate
0
|
01-16-2016, 08:27 AM | #135 | |
Second Lieutenant
99
Rep 250
Posts |
Quote:
|
|
Appreciate
0
|
01-16-2016, 09:13 AM | #136 | |
Colonel
614
Rep 2,410
Posts |
Quote:
__________________
2011 335d 11.68 @ 125.71 mph 1/4 mile NHRA certified track
Ram Cummins with lots-o-mods |
|
Appreciate
0
|
01-16-2016, 09:16 AM | #137 |
I like to party
45
Rep 126
Posts |
|
Appreciate
0
|
01-16-2016, 09:21 AM | #138 |
Colonel
614
Rep 2,410
Posts |
Thanks. I think the boost vs drive pressure info would be extremely helpful in comparing various options. If we could get MAF data along with this then that would be even better... but that takes a lot of fussing around since at these levels the OEM MAF becomes useless.
__________________
2011 335d 11.68 @ 125.71 mph 1/4 mile NHRA certified track
Ram Cummins with lots-o-mods |
Appreciate
0
|
01-16-2016, 09:58 AM | #139 |
Banned
798
Rep 1,633
Posts |
Clipping is on the exducer side of the turbine. Cutting an exducer down at the root will weaken the turbine. Therefore, material is removed progressively, moving out to the tip. Hence, describing the removal in terms of the angle that is created.
This is an inexpensive countermeasure to excessive drive force. Unfortunately, it does reduce drive force at all flow levels. Therefore it does effect the transient response of the turbo. The R2S turbo system can mitigate some of that by adjustment of the HP to LP transition. To some extent, the software takes care of that automatically. |
Appreciate
1
|
01-16-2016, 12:12 PM | #140 | |
Private
21
Rep 64
Posts |
Quote:
Anyway, thanks for the information you've already posted here |
|
Appreciate
0
|
01-16-2016, 12:17 PM | #141 | |
Banned
798
Rep 1,633
Posts |
Quote:
Also, what is commonly called "drive pressure" is an incomplete measurement to understand the work going into the turbine. Physically, it is the difference between EBP at the manifold and EBP after the turbine that creates the drive (I'm purposely not including impulse forces). This is exactly what was seen when the DOC/DPFs started coming off and turbo performance improved. The next layer of complication is turbine efficiency, which varies with flow, expansion ratio, and turbine speed. Any "linear" analysis of the dynamics can lead to false conclusions. So, lets backup and discuss the difference between your IWG and EWG, because I think that is significant. I'll start with the EWG, because that's easy (well, it's Saturday, and I like to ease into Saturday ) Your EWG is completely out of the flow path of the turbine. It's exhaust does not even return to the main exhaust. Other than an imbalance of EBP at the individual cylinder ports, I can't think of a more effective/efficient setup. Now, the IWG. It isn't even good for an IWG. First it is not isolated from the turbine flow path. In fact, it interferes with the turbine flow path. Contrary to intuition, abrupt expansion can have greater flow resistant than abrupt contraction. This creates pressure in front of the exducer. For the same manifold pressure, the work that can be transferred to the turbine is reduced. So, to get the same boost from the compressor requires greater manifold pressure to the turbine. I should note that an internal IWG can cause flow disturbances on the inducer side of the turbine,also. The higher EBP in front of the turbine causes 2 problems. First, it just creates more work for the piston on the exhaust stroke. Energy from the fuel that could have been used to propel the car is being used to push out exhaust. Just to put some magnitude to all this, it will take more than 70HP of shaft power to attain these levels of pressure and flow. Second as the ratio of manifold EBP to boost rises, more residual exhaust remains in the cylinder and potentially a 1% to 2% backflow at the beginning of the intake stroke. If the fuel flow remains the same AFR will drop and EGT will rise. Now here is an example of a divided wastegate outlet. And a divided exhaust flange continues the separation and extends the length. At a minimum, we would like to see the length of the exit duct from the exducer to be 3 times its diameter. Ideally, we'd like to see the expansion take place in a 10 degree flare. Merging of wastegate and turbine, well downstream of the turbine. And finally, when an IWG would perform nearly as good as your EWG. Here, the only improvement would be isolation of the wastegate input side from the turbine inducer - just as your EWG does. Basically, TDIwyse, you have done a very good job integrating your EWG. The OEM IWG configuration cannot compete! |
|
Appreciate
2
|
01-16-2016, 12:36 PM | #142 | |
Colonel
614
Rep 2,410
Posts |
Quote:
Since you showed those images, I should update that I had that according flex pipe spring a leak, and since went to a solid mandrel bend stainless pipe for the manifold to EWG connection. Question for those who've done turbo swaps on this platform... if we didn't need the IWG any longer, does that open up any other possibilities for turbo upgrade options? Different hot side possibilities? Or is space so tight, and the integration into the R2S system such, that we are extremely limited on what can be done?
__________________
2011 335d 11.68 @ 125.71 mph 1/4 mile NHRA certified track
Ram Cummins with lots-o-mods |
|
Appreciate
0
|
01-16-2016, 12:49 PM | #143 |
Private First Class
55
Rep 157
Posts |
.
Thank you DWR. TDI wyse, read carefully the end. Well, maybe I can tell you so much, that the diameter of the turbine is of course important, but the shape of the turbine wing is other and how much blades there are. No need to increase the diameter so much, if just take a notice to all these other things also. |
Appreciate
0
|
01-16-2016, 01:11 PM | #144 | |
Colonel
614
Rep 2,410
Posts |
Quote:
Does this image of the M57 turbo on the 535d have an isolated IWG passage like DWR was describing? http://dencodiesel.com/products/turb...s-bmw-535d-m57 Is the hot side on the 535d different than the 335d?
__________________
2011 335d 11.68 @ 125.71 mph 1/4 mile NHRA certified track
Ram Cummins with lots-o-mods |
|
Appreciate
0
|
01-16-2016, 01:37 PM | #145 |
New Member
2
Rep 24
Posts |
Hotside in 335D and 535D LCI is technically same. They have different part number and from DWR posts second picture you can see support from block to housing and where brace connects -thats the difference between housings.
Pre-lci 535D is totally different housing but i think turbine wheel is same. |
Appreciate
0
|
01-16-2016, 01:42 PM | #146 | |
New Member
2
Rep 24
Posts |
Quote:
That flap in intake is the flap that is separates small and big turbo at about 3000rpm. That is also the reason why you can't use universal exhaust housings. There you can find pictures how R2S system operates; HERE Last edited by AiM; 01-16-2016 at 01:48 PM.. |
|
Appreciate
0
|
01-16-2016, 02:17 PM | #147 | |
Colonel
614
Rep 2,410
Posts |
Quote:
I suppose it would be possible to form an isolation between the IWG and turbine outlet with a custom made downpipe? Kinda have a shaped section for the IWG flow such that it protrudes into the area where the IWG is located? But it looks pretty tight in there already...
__________________
2011 335d 11.68 @ 125.71 mph 1/4 mile NHRA certified track
Ram Cummins with lots-o-mods |
|
Appreciate
0
|
01-16-2016, 02:27 PM | #148 |
Private First Class
30
Rep 93
Posts |
I know the dude from Finnish BMW and MB forums, he has a crap ton of knowledge from engine builds, diesel tuning and turbos, but not the English skills to back them up unfortunately. Hence he reads a bit cryptic at times
Tuikku mate, if you ever need translations help, hit me up! |
Appreciate
1
|
01-16-2016, 11:47 PM | #150 | |
Banned
427
Rep 1,040
Posts |
Quote:
Looking forward to seeing some BDP dyno results..... |
|
Appreciate
1
|
01-17-2016, 01:14 AM | #151 |
Second Lieutenant
79
Rep 244
Posts |
|
Appreciate
1
|
01-17-2016, 02:05 AM | #152 | |
Private First Class
55
Rep 157
Posts |
Quote:
Iīm still waiting the results ... My opinion is that TDIwyse has proved here many times, that up to ~420hp level, the orig solution with EWG is the best, IWG works, but EWG is better. My own experience about this is equal. And I am not talking only for my own car, but I have done few these to other also ... But, what happens above ~420 level, TurboTim do not know anything about that . AiM have a good result, very good. But Iīm quite sure, that he could get the same result by only doing the all other improvements he done and nothing to the turbo wings. For me, the main thing is understand the working principals and change the minimum number of parts, only what is necessary and let the others be there. I have build many of these by this method - and they work, well. The only solution, where turbine clipping can work, might be with orig compressor. Work and AiM, nice to see you here. Hopefully this donīt become an other Finnish BMW forum ... |
|
Appreciate
0
|
01-17-2016, 04:54 AM | #153 | |
Banned
798
Rep 1,633
Posts |
Quote:
An insert that blocks the IWG and transitions flow out the exducer to the exhaust pipe might be a nice touch. Last edited by DWR; 01-17-2016 at 05:27 AM.. |
|
Appreciate
0
|
01-17-2016, 05:26 AM | #154 |
Banned
798
Rep 1,633
Posts |
|
Appreciate
0
|
Bookmarks |
|
|