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Turbo rotaries, turbine sizes and back pressure

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Old Jun 13, 2005 | 03:50 PM
  #1  
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From: Drammen, Norway
Turbo rotaries, turbine sizes and back pressure

Hi,


After a little tuning session on the dyno today my 13BT made 438BHP (7400 rpm) and 450Nm (6500 rpm) at 1.2kg/cm2 boost. Exhaust temp is around 837C (1538F) and backpressure in the exhaust manifold is 1.5 kg/cm2 at peak hp.

My turbo is a 62-1 compressor with Q-trim and A/R 1.00 turbine housing. On our pistion engines we try to select turbine and trim to get the backpressure to catch up with boost just around peak hp, and we get excellent results this way.

Anyone have similar results on rotaries? I would like to lower my backpressure a little bit....

Btw, the engine got a little short break-in period and the cornes seals springs are probaly more or less flat. The engine has veeeery low compression, is very hard to start, but we were able to run 39 degrees of timing on 5500 rpm and 1 kg/cm boost without detonation (had to really push the timing to get those number with such low compression.

Regards,
Frode
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Old Jun 13, 2005 | 04:06 PM
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Are you running 1 pc ceramic seals? That might be causing your low compression and start up issues.
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Old Jun 14, 2005 | 03:56 AM
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From: lebanon
Originally Posted by 88fc3sw/HX83
Are you running 1 pc ceramic seals? That might be causing your low compression and start up issues.

Thats a poor responce/suggestion ....

I run and supply MANY sets of one piece ceramic seals and they have perfect compression readings, if you read his post carefully they had low compression after the dyno runs which = theraml overload of the sealing elements (very easy to do) and sounds like no or little spring tension left on seals and or warped ferrous seals (does nto happen with ceramics).

Please think before posting complete crap
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Old Jun 14, 2005 | 04:01 AM
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From: lebanon
Frode, where are you measuring EGT (pre or post turbine?).

What type of fuel are you running in your dyno tests also. It is VERY EASY to flatten apex seal springs and distort ferrous steal type apex seals on an engine dyno test. You need to run engines like that very heavy on the AFR just to cool these elements down or use water injection, also if you rotors do not have enough cooling oil flow rate and at a sutable temperature you can kiss you springs and apex's good bye very quickly as well.
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Old Jun 14, 2005 | 06:10 AM
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From: n
Dude, 1:1.25 ratio is pretty damn good!
Most people are in the 1:2 or 1:3 range!

I'm surprised the 1.00 A/R flows that well.
I would've thought it was too small to flow that kinda pressure ratios...


-Ted
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Old Jun 14, 2005 | 07:33 AM
  #6  
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From: Bayouself
This is an ignorant question ...because I dont know..how and what is used to measure the back pressure ?What section is this taken from?
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Old Jun 14, 2005 | 09:51 AM
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From: Drammen, Norway
Hi Rice,

Originally Posted by RICE RACING
Frode, where are you measuring EGT (pre or post turbine?).
I am measuring around 2 inches from the exhaust port, in each runner.

What type of fuel are you running in your dyno tests also. It is VERY EASY to flatten apex seal springs and distort ferrous steal type apex seals on an engine dyno test. You need to run engines like that very heavy on the AFR just to cool these elements down or use water injection, also if you rotors do not have enough cooling oil flow rate and at a sutable temperature you can kiss you springs and apex's good bye very quickly as well.
Ok. I am running regular 98 octane RON with 1% 2-stroke oil premixed. Yep, the oil did get a little hot a couple of times, but a quick fix with a water hose zip-tied to the oil-cooler solved that pretty good.

I will take the engine apart tonight or tomorrow to take a look at it.

Thanks,
Frode
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Old Jun 14, 2005 | 09:52 AM
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From: Drammen, Norway
Originally Posted by APEXL8T
This is an ignorant question ...because I dont know..how and what is used to measure the back pressure ?What section is this taken from?
You are measuring the pressure between the engine and the turbine (in the exhaust manifold just below the turbo flange or in the inlet of the turbine housing)

--
frode
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Old Jun 14, 2005 | 09:55 AM
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From: Drammen, Norway
Originally Posted by RETed
Dude, 1:1.25 ratio is pretty damn good!
Most people are in the 1:2 or 1:3 range!
I guess it's ok then. I wont be boosting more than around 1.5 kg/cm2 so the backpressure wont climb that much...


I'm surprised the 1.00 A/R flows that well.
I would've thought it was too small to flow that kinda pressure ratios...
You know Ted... it's the inside that counts

Regards,
Frode
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Old Jun 14, 2005 | 03:26 PM
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From: Oregon
I'm talking about when compared to 2pc seals...He did also mention that his motor only got a SHORT Break-in!
Originally Posted by frode
Hi,

Btw, the engine got a little short break-in period and the cornes seals springs are probaly more or less flat. The engine has veeeery low compression, is very hard to start, (had to really push the timing to get those number with such low compression.

Regards,
Frode

I guess Ralph (Ground Zero 700HP FD Pineapple motor) and Rob (Pineapple Racing engine builder) don't know what their talking about huh!

Ohh, not to mention that I also am running 1pc Ceramics and I was experiencing his symtoms...but I'm wrong too!

Originally Posted by RICE RACING
Thats a poor responce/suggestion ....



Please think before posting complete crap
eye eye sir!

Last edited by 88fc3sw/HX83; Jun 14, 2005 at 03:43 PM.
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Old Jun 14, 2005 | 06:17 PM
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From: lebanon
When you have some data of relevance then talk to me and in a proper manner, I have MANY set ups run by very professional people who have no such symptoms or problems, because they do not exist.

The differences in compression are so minor that in a high HP application its like spliting hairs. So please get your facts straight. I know Ralph I deal with him I dont know Rob but he uses NRS product as well, feel free to tell either of them to ring me and I will set them straight since you feel like using their names to back up your stupid argument.

Last edited by RICE RACING; Jun 14, 2005 at 06:24 PM.
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Old Jun 14, 2005 | 06:57 PM
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WOW! some guys get nasty, ( WHOM THE GODS SHALL DESTROY,

THEY FIRST MAKE THEM MAD )
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Old Jun 14, 2005 | 08:21 PM
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Originally Posted by RICE RACING
When you have some data of relevance then talk to me and in a proper manner, I have MANY set ups run by very professional people who have no such symptoms or problems, because they do not exist.

The differences in compression are so minor that in a high HP application its like spliting hairs. So please get your facts straight. I know Ralph I deal with him I dont know Rob but he uses NRS product as well, feel free to tell either of them to ring me and I will set them straight since you feel like using their names to back up your stupid argument.

Yes RICE I am a tool and sorry for the stupid comments.

Last edited by RICE RACING; Jun 14, 2005 at 09:23 PM.
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Old Jun 14, 2005 | 09:08 PM
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Originally Posted by 88fc3sw/HX83
RICE I am a tool, sorry for the stupid comments !
I think he got mad at your post because you stating something as fact when its what your "heard" from somebody where as RICE RACING was stating facts from personal experience, which he has a lot of.

Just my .02

Last edited by RICE RACING; Jun 14, 2005 at 09:28 PM.
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Old Jun 14, 2005 | 09:26 PM
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From: lebanon
No BS will be tolerated in this thread or on this section, back your claims up or SHUT UP. Its that simple, and keep personal attacks out of it if you have nothing factual to say. Especialy if all you can retort with with third hand information and with adhominem style argument.

Last edited by RICE RACING; Jun 14, 2005 at 09:29 PM.
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Old Jun 14, 2005 | 09:38 PM
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From: lebanon
IF you have problems with one piece seals YOU ARE THE ONE who is having issues or YOUR BUILDER or something in your set up is ******* your seals, IT HAS NOTHING TO DO WITH ONE PIECE DESIGN V"S MULTI PIECE DESIGNS. Get that clear in your head and STOP posting rubbish.

Side note pulled down a motor with multi piece seals that would not start hot and it had very low compression and high EGT's it had warped apex seals after only 500km of driving, these were OEM 2 piece 3mm, based of this evidence 3mm multi piece seals have low compression and are not reliable so I would never run them in a car and you should look at this as its a probable cause, grow up mate and take note of what I am telling you... think before you ***** up a thread.
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Old Jun 14, 2005 | 11:51 PM
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Peter, I have missed you so...
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Old Jun 15, 2005 | 12:34 AM
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Originally Posted by 88fc3sw/HX83
Yes RICE I am a tool and sorry for the stupid comments.
hmm, Looks like Rice Racing edited 88fc3sw/hx83s' reply? Maybe Rice Racing should grow up!

and that Carl Byck guy sounds gay! lol
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Old Jun 15, 2005 | 12:43 AM
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Originally Posted by RICE RACING
No BS will be tolerated in this thread or on this section, back your claims up or SHUT UP. Its that simple, and keep personal attacks out of it if you have nothing factual to say. Especialy if all you can retort with with third hand information and with adhominem style argument.

Yes master, anything you say!
Maybe you should ban me and edit the rest of my other replies, that'll teach me!
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Old Jun 15, 2005 | 01:16 AM
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Originally Posted by ZoomZoom95
hmm, Looks like Rice Racing edited 88fc3sw/hx83s' reply? Maybe Rice Racing should grow up!

and that Carl Byck guy sounds gay! lol
Post count or age??? Why are you hiding??? Once again, Jim gets on a thread and BOOM, useless trash Go figure...
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Old Jun 15, 2005 | 05:21 AM
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I thought id browse this thread because the turbine back pressure subject is interesting me.... I think some guys on this thread need to take a few deep breaths.

anyway im curious about ceramic t45 turbines on high hp 13b and how streetable they are vs p trim or q trims.
i put a post up on the subject a wee while ago with not much success, and i was kinda hoping sence this thread is high profile at the moment and its sort of related to the topic unlike the rest of the abuse thats going on it at the moment, some one might have some experence with the large t45 style turbine and able to give me a bit of feed back.
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