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Discussion Starter #1
Mired deep in compressor maps I'm plotting all kinds of things using the handy tool on the ray hall site

link here:
http://www.turbofast.com.au/turbomap.html

btw the more time I spend learning the nitty gritty about turbos the more respect I have for FP the more research I do the more often I conclude I would pick the same combinations they do... but at any rate

heres a plot for a 60 trim T04E
I made some blah blah thrown together assumptions for VE and IC efficiency. Manipulating those #s has very little effect on the results.


now heres a plot for 60-1


heres enlarged maps with flow rates attached




my rev limiter is set at 7750 so I plotted that for the highest point.

Correspond the 7750rpm point on both plots to the enlarged version that shows flow in lb/min

60-1 at 7750rpm is about 35 or 36lb/min
60 trim at same RPM and boost is 42 or 43 lb/min

Am I to understand truly that at 7750rpm and 24 psi I am flowing _MORE_ on a 60 trim then a 60-1. It seems the logical conclusion here but I really had to get verification from a group more knowledgable then I. If this was true it would mean a huge mistake on the part of a lot of shops. Thats why I'm going back to the drawing board and asking did I do something wrong??

Please someone fill me in.
I think I'm plotting these correctly as I can draw the same line right across the map and it corresponds within 1lb/min to what the ECU is reporting back from my drag runs.

Did anyone else find it interesting that the frank series turbos never went to a larger compressor wheel then 60 trim but rather opened up flow on the hot side?

Larger turbos dont always flow more is no big secret but still this is a pretty drastic differential.
 

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BICTURBO said:
60-1 at 7750rpm is about 35 or 36lb/min
60 trim at same RPM and boost is 42 or 43 lb/min
There's something wrong, those turbos flow more than that. 35lbs is 16g territory, 42lbs is about equal to a 20G.

I do know that the 60trim is happier at 28psi than the 60-1, based on what two friends of mine have done. At 22psi the 60-1 seemed to make a little more power though.
 

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Discussion Starter #3
Re: Re: Am I hallucinating (turbo flow maps)

Nick 92 TSi AWD said:


There's something wrong, those turbos flow more than that. 35lbs is 16g territory, 42lbs is about equal to a 20G.

I do know that the 60trim is happier at 28psi than the 60-1, based on what two friends of mine have done. At 22psi the 60-1 seemed to make a little more power though.
but when they quote flow numbers for a turbo its always the max flow but your motor doesnt necessarily land at that point in the turbos map. Does that make sense. Yah sure 42lbs is 16gs max flow but plot a 16g and your not going to flow 42lbs on a 16g.

Max flow does not equal actual flow. I'm just arguing to try and understand I'm not trying to assert some greater knowledge here. Is my base assumption incorrect? I can look at the logs from the DSMlink board and they all coinside with how the maps predict on all the turbos. Thats why I'm wondering whats really going on.
 

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I understand what you are saying. From everything I have seen with DSMs, when tuned properly (key words ;) ), each lb of air equals around 10hp at the crank.
Running 22psi (pump gas and water injection) with a T3/T4 that had a 60-1 compressor wheel a local dsmer pulled 120mph traps. That's a little bit over 400hp, which would mean over 40lbs of air from the turbo.
Yes I know this is taking a lot for granted and making a lot of generalizations, but so is the Ray Hall generator. On the main GN site there is a good article on compressor maps that will show you how to do the real math (if you do a search in gen tech there is a thread with a link from Dec. 00). I always ended up with slightly different points doing it myself, that seemed close to what happens in the real world. Even then sometimes a turbo doesn't behave how the paper says it will. Everyone I have talked to ended up having the 50 trim wheel go over the surge line, but I have NEVER seen it actually happen on a car.
What I'm getting at is those points might be totally wrong in relation to what happens in the real world. Espically considering those maps are made with a specific compressor housing and the turbine side isn't even put into consideration.
 

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Discussion Starter #5
Nick 92 TSi AWD said:
I understand what you are saying. From everything I have seen with DSMs, when tuned properly (key words ;) ), each lb of air equals around 10hp at the crank.
Running 22psi (pump gas and water injection) with a T3/T4 that had a 60-1 compressor wheel a local dsmer pulled 120mph traps. That's a little bit over 400hp, which would mean over 40lbs of air from the turbo.
Yes I know this is taking a lot for granted and making a lot of generalizations, but so is the Ray Hall generator. On the main GN site there is a good article on compressor maps that will show you how to do the real math (if you do a search in gen tech there is a thread with a link from Dec. 00). I always ended up with slightly different points doing it myself, that seemed close to what happens in the real world. Even then sometimes a turbo doesn't behave how the paper says it will. Everyone I have talked to ended up having the 50 trim wheel go over the surge line, but I have NEVER seen it actually happen on a car.
What I'm getting at is those points might be totally wrong in relation to what happens in the real world. Espically considering those maps are made with a specific compressor housing and the turbine side isn't even put into consideration.
Thats really impressive for your friends car. Do you know what kind of timing he was getting with the alcohol inj? Dual or single nozzle system?

I get well over 40lbs at 22psi on the 60trim. So I dont quite understand what the implication means but I got the other thing your saying

The ray hall calculator makes a lot of assumptions, definately believeable. I had been looking everywhere for the data on how to make the calculations myself I really appreciate the lead on where to look.

Your friend with the 60-1 does he have a DSM Link? If so it would be really interesting to compare airflow #s from 22psi logs.

THe reason I'm dying to really understand this is I'm looking for an upgrade on my current turbo and its starting to look like the only way to really upgrade is GT Series or T series
 

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Discussion Starter #6
BTW I wonder if the maps are made for full T4/T4 I wouldn't be suprised at all.
 

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Discussion Starter #7
Do you have a link to the GN forum? I checked the one I read from time to time and I'm not sure its the right one.
 

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BICTURBO said:


Thats really impressive for your friends car. Do you know what kind of timing he was getting with the alcohol inj? Dual or single nozzle system?

I get well over 40lbs at 22psi on the 60trim. So I dont quite understand what the implication means but I got the other thing your saying

The ray hall calculator makes a lot of assumptions, definately believeable. I had been looking everywhere for the data on how to make the calculations myself I really appreciate the lead on where to look.

Your friend with the 60-1 does he have a DSM Link? If so it would be really interesting to compare airflow #s from 22psi logs.

THe reason I'm dying to really understand this is I'm looking for an upgrade on my current turbo and its starting to look like the only way to really upgrade is GT Series or T series
I'm not sure, I haven't seen his car or talked to him in quite a while (my car his been down and I haven't been to the track).

I was saying the 60-1 seems to flow around that much too.

http://www.gnttype.org/techarea/turbo/turboflow.html

No it's a 1G awd with a VPC.

How much power do you really want? Personally if I were going bigger I'd look at a GT series turbo, the ballbearing cartridge pretty much eliminates lag between shifts. Look at what Magnus has done with his GT35R on their shop 2G, 147mph.
I've always liked the T66 also.
 

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Discussion Starter #9
Nick 92 TSi AWD said:


I'm not sure, I haven't seen his car or talked to him in quite a while (my car his been down and I haven't been to the track).

I was saying the 60-1 seems to flow around that much too.

http://www.gnttype.org/techarea/turbo/turboflow.html

No it's a 1G awd with a VPC.

How much power do you really want? Personally if I were going bigger I'd look at a GT series turbo, the ballbearing cartridge pretty much eliminates lag between shifts. Look at what Magnus has done with his GT35R on their shop 2G, 147mph.
I've always liked the T66 also.
Its looking more and more like the GT series is truly the only way to go. no lag between shifts?? I've lost races just from that one thing before! GT35R looks perfect to me.

I checked on magnus site and they listed the turbos as having a T3 turbine housing. I'm assuming this means it would bolt right up to my T3/4 manifold the prices were awesome as well. Thanks for the info nick. I'm suprised nobody else chimed in with some data on this. Even anecdotal evidence is helpful
 

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According to the first two plots both turbos are way past the surge line until past 6000 rpm. The compressor ought to be in the area where its most efficient and always to the rifht of the surge line.

It looks like the dots were plotted at about 40 psi - it looks like the "boost" in the calculator ought to be above atmospheric (14.7 psi) so you ought to plot it at about 10 psi boost (24-14=10 psi boost). If you look at the plot the pressure ratio is about 2.6 what equates to about 39 psi. 24 psi is about pressure ratio of 1.6.

Stevan
 

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Discussion Starter #11
plotted that way it results in 25lb/min for the 60-1 and 30 for the 60 trim same flow discrepancy problem. On top of that then the amount of power the cars are making is drastically inacurate and contradicts the datalogs and dyno runs for a lot of cars. The efficiencies certainly look better tho.
 

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Discussion Starter #14
the compressor efficiency number do not affect the plot only the HP calculator which I cut off for this.

and 60 trims peak 78% I believe I just stuck 80 across the board for the hell of it. I dont think the HP calculator matters much.

I used Paint Shop Pro to capture it

also you can try pushing the alt-printscreen button in windows it copies the current window to the clipboard then you can use anything like photoshop, paste it in and save the file
 

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This is about third time that i've tried to post this. I have a question about VE that the program uses. To my knowledge boosted engines have VE above 100 and that is the whole point of boosting. Do we input naturally aspirated VE for the engine and the program calculates VE under boost, or are we supposed to input boosted VE? When VE higher than 100 gets entered the plotted points move to the right indicating a higher mass flow rate.
 

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Discussion Starter #16
MIdsm said:
This is about third time that i've tried to post this. I have a question about VE that the program uses. To my knowledge boosted engines have VE above 100 and that is the whole point of boosting. Do we input naturally aspirated VE for the engine and the program calculates VE under boost, or are we supposed to input boosted VE? When VE higher than 100 gets entered the plotted points move to the right indicating a higher mass flow rate.
Thats a really good question. I havent got a clue the answer that. Did you try emailing the webmaster of the site maybe?
 

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dont study compressor maps too hard. they just get you in the ballpark. there is way more going on that a map cant predict.

the 60-1 outflows a 60 trim.

gary andriotis made 480hp from his 60/3/63. good for 10.7 at 132.
he switched to a 60-1 with same setup. dynoed at 525hp.

other have made 600hp with the 60-1 wheel.
 

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Discussion Starter #18
lancerman said:
dont study compressor maps too hard. they just get you in the ballpark. there is way more going on that a map cant predict.

the 60-1 outflows a 60 trim.

gary andriotis made 480hp from his 60/3/63. good for 10.7 at 132.
he switched to a 60-1 with same setup. dynoed at 525hp.

other have made 600hp with the 60-1 wheel.
Damn thats sweet and so is your motor.

I'm definately getting the feeling compressor maps are not really very helpful at all.
 

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Discussion Starter #20
racerxadam said:
pretty good discussion on reading compressor maps here
Thanks also BTW I reverse engineered the Java calculator so you can put in your airflow at RPM and return your VE :-D

also I plotted the map by hand from the datalogs and the tool on the ray hall site was almost precise (at least on my turbo)
 
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