m42racer

I'm out of the office this week travelling, but I will answer your questions.

What I am trying to bring to buyer's attention is that most of the time, this testing is never done. I see many turbo's damaged from overspeeding, totally due to lack of information given to the customer. How many posts here ask, "What boost are you running" or "what turbo config are you running".

I cannot supply maps for reasons stated, nor can I supply maps from manufacturers I do not represent. But I can offer some insight into ways we can carefully run Turbo's without damaging them. I have read here posts by some that state that they are running outside or close to it, the turbo's efficency. My ponit is without maps or speed, or pressures from both sides taken, how do we know where we are.

I have asked if a speed counter can be made that will input into an EFI, or to some sort of stand alone device for those without EFI.

As for the old maps, its more a case of "old wine in a new bottle". Most maps I have studied are not even close to what is been sold. There is a large retailer in the LA area who has been selling hybrid turbo's for years without any testing, and providing old maps for reference. Yes they maybe close, but when the turbo breaks, how close is close enough? I hope the speed counter will help everyone. Although no map will be available to reference to, sudden increases in speed will inform you of possible failures are close by.

And Luke, if you feel its not worth YOUR bother, that ok too. No harm meant or taken.

Edman951

M42racer,
Will you look into my questions 4 replys up.
I sure would like to hear from a turbo expert.
Do you know if the information given on this site are good for the new gt turbo's?
<a href="http://www.turbopiping.com/pages/5/index.htm" target="_blank">http://www.turbopiping.com/pages/5/index.htm</a>
Thanks
<img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />

nine-44

Try to do some number crunching and read a few good books on turbocharging. I think you will find some answers there. As far as the old maps go, I guess we gotta trust the guys that do it for a living and know from real world experience. You just gotta find the people that know about turbos. Since you seem to be the guy that would know, care to enlighten us? Or, are you just going to say, I know and I'm smart, and not tell us anything relevant? Don't just say stuff to hear yourself say it and make yourself feel cool. I realize that people don't like to give all the competition their homework. I haven't seen a post by you yet that shows that you know anything significant. They all seem to be questions and theory, and when someone tells you something to try to help, you seem to try to outwit them and say you know more. BTW, didn't you have a different line of work in another post? Is AMAF back, or am I paranoid? Not really trying to be an punk, I just don't understand the questions you ask, comming from such a (supposedly)highly edjucated person?

nine-44

I just did a search, on your member#12308. You have nothing positive to offer, ever! You post nothing to help, or help the list. You constantly badmouth the tuners. And constantly tell people they know nothing and you know more. Why? I can understand if you had a bad or good experience with a tuner. I don't see any cars in your signature, what are you playing with? I don't see you being a rennlist member either? I don't have a pot to **** in, and I'm a member. (remember me now?) So, what's your deal, to be honest, I get bent out of shape when I see your name! I see NO reason to be such an *** to people? Why?

nine-44

PS, if anyone thinks that I am the one being an ***, let me know. I think I've seen enough to draw my judgement on m42.

m42racer

I agree! Instead of bashing him here, why don't we take him out back and beat the crap out of him!

See Ya!

Luke

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by nine-44:
<strong>PS, if anyone thinks that I am the one being an ***, let me know. I think I've seen enough to draw my judgement on m42.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">I'm with you. i get the feeling he's looking for a fight. o well, nothing better to do I guess.

nine-44

See, more sarcastic BS. No explanation of why he feels the need to rain on everyone. I just don't get it. I try my best to give all the GOOD advice I can to fellow listers and share my expeiriences. I feel that pretty much all of the other listers try to do the same.

RobNL

Hey guys, can we go back to the main issue? I still want to know a little bit more about turbo's and their efficiency.

In my previous post I showed a map of my Kokeln turbo. If I read it correctly, does it say that at a pressure ratio of 2.3 (= 1.3 bar boost? = 18.85 PSI) my turbo is at maximum an any higher boost level won't improve performance?

nine-44

As far as I know, the center "island" is your window of maximum efficiency. The turbo will go beyond that, but creating more heat and diminishing performance as well as efficiency. I've read quite a few good books on turbos, but they don't seem to give a good explanation on reading maps. This is my understanding of them, don't take it for hard fact. I think I'm pretty close to the basics. Does anyone know where a good book or site is that explains them, in-depth?

Matt Sheppard

Andy and all:

You can get a real good handle turbos in Corky Bell's book "Maximum Boost" - about $25 shipped from Amazon.com.

I have read it no less than twice (I seem to reread different sections at different times) and I still learn new things or connect concepts that I didn't previously. I had the hardest time with the section on selecting a turbocharger because it goes through so much "new-to-me" tech., but it will tell you how to read a compressor map and where to match your CFM needs with a compressor that is efficent in the spot you want it. It should be helpful for any listee - pro or not. It goes into much more than turbos and addresses the entire system. It's copyrighted 1997 so I would guess IT is not too old

P.S. I also REALLY like "How to Rebuild a 911 Engine" by Wayne Dempsey ©2003 - even though I dont own a 911, the general ideas apply to any engine and more directly to Porsche engines (allusil cylinders and all that). These two books I read the most out of anything I have and usually just before I go to bed and my wife thinks I am crazy. "I understand how it would be interesting to you to rebuild an engine, but just reading about doing it! . . .over and over?" she says.
OK, I like to understand things real well in my mind before I impliment them or buy lots of $$$ parts. Obsessed, maybee. . . but crazy,? No.

nine-44

I got Maximum Boost and both prints of Turbocharging by Hugh McInnes. Both are very good books, I want to get the 911 book for general reference. I've thumbed through it and it seems to be a good read. I guess I need to go back through the Max book again, last time I read it was when I was reading for exhaust design. Guess I need to read it for map breakdown. Thanks BTW, this is my reading, but... Turbocharging, seems to be older and alot of applicable hard fact and #working explained easily and life long experience. MaximumBoost seems to be alot of explanation, some opinion(very applicable opinion)and preference, also alot of real world experience. Happy reading!

RobNL

Thanks. I'll read the book "Maximum boost" first before I start asking questions about turbos again.

At the beginning I thought that buying a ??? RWHP kit (in my case the LR package) was enough to improve performance but now I also want to understand why and how this combination does work and how much other options will improve the performance even more, without damaging the engine.

Russ Murphy

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"> In my previous post I showed a map of my Kokeln turbo. If I read it correctly, does it say that at a pressure ratio of 2.3 (= 1.3 bar boost? = 18.85 PSI) my turbo is at maximum an any higher boost level won't improve performance? </font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Almost, but not quite. Those "islands" on the map show the expected efficiency ranges for this compressor. Yours aren't labeled, but they usually range from around .73 down to .60. Your map shows a max volume of 857cfm (60lbs/min) before going off the edge of efficiency. What that % is, isn't labeled and is to some extent arbitrarily picked (62% is OK, but 61% isn't?) The compressor is fairly efficient at well over 2.3 bar, but at a lower volume. I'm kinda fuzzy here, but where you are on the map in regards to PR/volume is more or less dictated by the shaft that the compressor wheel is connected to - the turbine, as well as your motor volume and head design.