cygnusx1 Posted October 16, 2006 Share Posted October 16, 2006 Look what I found!! I wonder who put this together? Kudos to you. http://www.mygen.com/users/dbruce/myz31/TurboMaps/L28ET%20Engine%20Air%20Flow%20and%20Turbo%20Compressor%20Maps.htm Quote Link to comment Share on other sites More sharing options...
sweetleaf Posted October 16, 2006 Share Posted October 16, 2006 Agreed , Sweet page.. Quote Link to comment Share on other sites More sharing options...
rztmartini Posted October 16, 2006 Share Posted October 16, 2006 I used that page when i was picking a turbo...really helped how to understand and read compressor maps Quote Link to comment Share on other sites More sharing options...
Noddle Posted October 17, 2006 Share Posted October 17, 2006 looks like the formulas are straight out of "Maximum Boost" book, I wrote this to help me do the same thing, pic included. added lbs/min Quote Link to comment Share on other sites More sharing options...
BirdmanZ Posted October 17, 2006 Share Posted October 17, 2006 Anyone else notice that he has 10 psi as 1.68 bar? That would make 5.95 psi 1 bar. Last time i checked 1 bar was 14.7 psi. Am i wrong somehow? Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted October 17, 2006 Share Posted October 17, 2006 10psi = (14.7+10)/14.7 = 1.68 Pressure Ratio. 1 pressure ratio is atmosphere. Dave Quote Link to comment Share on other sites More sharing options...
TimZ Posted October 18, 2006 Share Posted October 18, 2006 ...and, if you want to be nitpicky, 1 bar = 14.5 psi 1 atmosphere = 14.7 psi Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 18, 2006 Share Posted October 18, 2006 TimZ, you beat me to it! Working for Atlas Copco Compressors, that particular fact was drummed inot our heads repeatedly as in screw compressors, .2psi WILL be the difference between a compressor that runs, and one that is shutting down on compressor stage outlet high temperature... Quote Link to comment Share on other sites More sharing options...
TimZ Posted October 18, 2006 Share Posted October 18, 2006 TimZ, you beat me to it! Every now and then, even a blind squirrel finds a nut... Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted October 19, 2006 Author Share Posted October 19, 2006 Here are some more nuts for the squirrels. http://64.225.76.178/catalog/Default.htm Quote Link to comment Share on other sites More sharing options...
Clifton Posted October 23, 2006 Share Posted October 23, 2006 He did alot of work but based on my known hp at 16 and 22 psi it's a little low on his lb/min numbers. He also has the boost curve on the compressor maps. It's not that easy without knowning the hotside specs. He has the 60-1 making 20 psi before 3000 rpms. Maybe with a 5th gear pull from from 2k with the stock hotside, but who would run that set up, it would be a poor match. I wouldn't base my turbo choice off of it. Quote Link to comment Share on other sites More sharing options...
Noddle Posted October 23, 2006 Share Posted October 23, 2006 He did alot of work but based on my known hp at 16 and 22 psi it's a little low on his lb/min numbers. He also has the boost curve on the compressor maps. It's not that easy without knowning the hotside specs. He has the 60-1 making 20 psi before 3000 rpms. Maybe with a 5th gear pull from from 2k with the stock hotside, but who would run that set up, it would be a poor match. I wouldn't base my turbo choice off of it. Hi, I dont know much about turbos, But looking at the information he posted, he is not saying the "T04B-60-1" was the better choice, my understanding on what he said was the best turbo choice was the "T04E-50" Nigel Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted October 23, 2006 Share Posted October 23, 2006 That page has misapplied those formulas for the reason Clifton hinted at. He has mapped a straight line from 20% at 1:1 PR, increasing in pressure ratio linearly to his `knee-point' where full boost is reached. It doesn't happen that way. Show me a T61-1 equipped L28 that will make positive manifold pressure at ~1300rpm (~20% redline) and 20psi by 3250. My GT35R (ball bearing, and smaller than a T61) has only JUST gone positive pressure by 3250 and 20psi isn't seen until 4500 or later. And, the increase in boost/PR with revs is not likely to be that linear. In short, a highly simplistic view of things, and not worth the electrons that were used to deliver it to you. Dave Quote Link to comment Share on other sites More sharing options...
Clifton Posted October 24, 2006 Share Posted October 24, 2006 Hi, I dont know much about turbos, But looking at the information he posted, he is not saying the "T04B-60-1" was the better choice, my understanding on what he said was the best turbo choice was the "T04E-50" Nigel I may have worded that wrong, I wan't trying to say he was favoring one over the other. Just the info he has posted could lead one to choose a turbo that might not be the right one. I was trying to say it might be possible for such a low boost threshold with a 60-1, but the hotside would have to be on the small side (stock) and that would be a poor match for the compressor and limit the HP potential by alot. Quote Link to comment Share on other sites More sharing options...
Noddle Posted October 24, 2006 Share Posted October 24, 2006 That page has misapplied those formulas for the reason Clifton hinted at. He has mapped a straight line from 20% at 1:1 PR, increasing in pressure ratio linearly to his `knee-point' where full boost is reached. It doesn't happen that way. Show me a T61-1 equipped L28 that will make positive manifold pressure at ~1300rpm (~20% redline) and 20psi by 3250. My GT35R (ball bearing, and smaller than a T61) has only JUST gone positive pressure by 3250 and 20psi isn't seen until 4500 or later. And, the increase in boost/PR with revs is not likely to be that linear. In short, a highly simplistic view of things, and not worth the electrons that were used to deliver it to you. Dave Is this what you are saying ?, not sure of the numbers though, since im new to turbos, i'm trying to get my head around it, I ploted the lines (roughtly) from these figures, (not sure if the will line up in here) 168 Cubic Inches 2.75 Liters 10 Boost 1.68 Pressure Ratio 0.80 Ev -------- 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 RPM 0.90 1.35 1.81 2.26 2.71 3.16 3.61 4.06 4.52 4.97 5.42 5.87 Mim lbs/min, PR = 1 2.26 3.39 4.52 5.64 6.77 7.90 9.03 10.16 11.29 12.42 13.55 14.67 Max lbs/min, PR = 1.68 4.52 6.77 9.03 11.29 13.55 15.80 18.06 20.32 22.58 24.83 27.09 29.35 Max lbs/min, Turbo Is this what you mean ?, that the turbo will not spool at the lower revs ? Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted October 25, 2006 Share Posted October 25, 2006 The actual plot of air use would look like a stretched or elongated or italicized S instead of rising in a straight (diagonal) line, then horizontally to redline... Basically, it means that surge is not quite as much of a problem with some of the bigger turbos as the diagrams imply, and that when accelerating, the path will be more toward/in the efficiency island. If you have a copy of Hugh MacInnes' TURBOCHARGING, you'll know what I am talking about. Hope this helps... Quote Link to comment Share on other sites More sharing options...
Noddle Posted October 26, 2006 Share Posted October 26, 2006 The actual plot of air use would look like a stretched or eleongated or italicized S instead of rising in a straight (diagonal) line, then horizontally to redline... Basically, it means that surge is not quite as much of a problem with some of the bigger turbos as the diagrams imply, and that when accelerating, the path will be more toward/in the efficiency island. If you have a copy of Hugh MacInnes' TURBOCHARGING, you'll know what I am talking about. Hope this helps... Thanks for that, I thought that may be the case as the turbo winds up, but the book I was reading, didnt show that (Maximun Boost),or I didn't read it, any way I have ordered a copy of "TURBOCHARGING", so hopefully this will explain it better. and thanks again, for not shooting me down, as I have said i'm new to all this..big learning curve.. Nigel Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted October 27, 2006 Share Posted October 27, 2006 This is where I would say that there is no such thing as a dumb question, except that I HAVE heard some dumb questions - like after I got run over by a Lincoln TownCar (leg) when on a motorcycle and someone asked if it hurt.... No joke. Very rarely will anyone on this board deride an honest question, or anyone for asking one - I consider everyone here a class act in that regard. We are all happy to help - even if the help is in the form of "maybe you shouldn't try doing it yourself" - a situation that has sprung up occasionally. I remember one case where someone asked how to remove a carb from a V8 engine - no kidding! I will have to admit that I responded by saying that if he couldn't look at it and see how, he should let/pay someone else do it....Notice that I did not deride him. You didn't even come CLOSE to asking a silly question - glad we could be of help. Quote Link to comment Share on other sites More sharing options...
wigenOut-S30 Posted August 9, 2009 Share Posted August 9, 2009 I wanted to bring this thread back to life, After using the Squirrel Performance website, It looks like the Super.50 trim would be the ticket with boosting up on the lower side of 3Krmps and still have enough to flow on the top end. The turbo Im looking at going with will have a.63 exhaust housing with a stage5 wheel. But looking at this site it looks like the T61 compressor wheel would be awesome. I just have a hard time believing that as the T61 wheel is kinda large!. thoughts? My goal is( would like full boost 19-20psi in 2nd or 3rd by 34-3500RPMs) and still have enough on the top end to rev to 6500. I have looked at the compressor map for the S200 bullseye turbo and if I had the money.. I think that turbo is the Ticket for our L28 engines. could someone check my calculations on it to make sure Im not off my horse here.. the wheels I was looking at are the to4E super50, T61, 60-1 and of course LOVE the GT3076R, and bullseye S200. http://www.squirrelpf.com/turbocalc/index.php?version=4&target_peak_power=380&pr_ref=14.5&engine_disp=2.800&engine_disp_factor=0&target_af=12&bfsc=0.47&max_ic_loss=2&rpm_redline=6500&rpm_peak_power=5500&rpm_max_boost=3400&rpm_min_boost=2800&vol_1=75&vol_2=82&vol_3=87&vol_4=82&vol_1=75&vol_2=82&vol_3=87&vol_4=82&intake_temp_1=90&intake_temp_2=92&intake_temp_3=110&intake_temp_4=118&turbo_n=1&map_sel0=58 Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted August 9, 2009 Share Posted August 9, 2009 Gabe: For sheer top end performance, I'd say the T61, but I believe that for road and track use the best of the non ball bearing units would be the TO4E 60 Trim. Imagine that eloongated "S" going from bottom left to the max on the squirrel site running either right through or right alongside the highest efficiency island on the map for it - we're talking area under the curve man! It looks like it would beat the 50 trim easily... Quote Link to comment Share on other sites More sharing options...
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