2LiterTurboSeR

I knew that there was a broader region of people on here that were educated on reading compressor maps and knew more about turbocharged vehicles, and we had this debate on SR20Forum, so I was gonna see if I could get any different input here.

I'm not actually capable of reading compressor maps. This is the map of my turbo (T4 60-1, .70 a/r. p-trim wheel, T04S housing) that I will be running on my 2.0 SR20De Se-R.



Can anyone tell me when I will see full boost, or even boost at all? I of course have a 3 inch turboback, 2.5 in i/c piping and all the other works, No cams yet though. The car more than likely will be revved to 8k rpms.

Any help is appreciated, thanks in advance!

I can provide any information needed.

tony1

Just out of curiosity, going by that compressor map, where did the members of the sr20 forum think it would spool?

2LiterTurboSeR

Well, only one person really had any estimate on spool, and it said he thought it would be around 4700 rpms's. Another member created a little color diagram that showed that I wouldn't quite be in the "Sweet spot" on the turbo, even at 8k rpms.

Quoted:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skyliner &raquo;</TD></TR><TR><TD CLASS="quote">
This is where you will be operating on the compressor map. Left hand side of line is 3500rpm, right side is 7500rpm. Red = 10psi, yellow is 14psi, blue is 20 psi. Looks like you will be in surge till about 5000rom and you'll never get in the compressor's sweet spot.</TD></TR></TABLE>


Another member said that his calculations were off a little bit for the better, but didn't post up a graph or anything, so everyone has their own mixed opinions so I'm not really figuring out exactly if the turbo is too big or too laggy for my car.

Finland

I don't have enough information about your vehicle to calculate this properly, but my opinion is that you will probably be somewhere near the surge line with your setup. I think that turbine is too big. I think that a 60-1 is going to behave like an on-off switch. It will pull hard way up top, then the fun is over. I'd probably go with something more fun like a T3/T4 hybrid that will be overall more efficient on a 2 liter.

BlueShadow

I just looked at the chart posted by skyliner and they look to be way on the low side. I'm a little rusty, but here it goes...

Based on my calculations a stock SR20DET flows a maximum of about 20 lb/min. So I figure at 15 psi or PR=2, you're flowing about 40 lb/min on the 60-1. And at 20 psi or PR=2.36 you're looking at about 47 lb/min. I dont know a whole lot about SR20's but it just looks like the numbers posted by skyliner were way too low. On the other hand my numbers might be way too high, but I didn't have a whole lot of info to work with. So my numbers might be about +/- 5 lb/min off, more then likely on the minus side.

EDIT: forgot to mention that the numbers I used were based on the theoretical CFM of an SR20 not the actual. That's why I say they might be on the high side.

2LiterTurboSeR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boondock Saint &raquo;</TD></TR><TR><TD CLASS="quote">I don't have enough information about your vehicle to calculate this properly, but my opinion is that you will probably be somewhere near the surge line with your setup. I think that turbine is too big. I think that a 60-1 is going to behave like an on-off switch. It will pull hard way up top, then the fun is over. I'd probably go with something more fun like a T3/T4 hybrid that will be overall more efficient on a 2 liter.</TD></TR></TABLE>

The previous turbo I was running was a T3/t4 50 trim on my car and the turbo was falling off up top. I got this turbo on a trade and it was brand new, while mine needed a rebuild in the near future.

Is there any information I can provide anyone to help clear up any questions?

Finland

what was the A/R on that t3/t4? Also you might have benefitted from a larger compressor. There are a ton of t3/t4 combos. I'm certain one of them would fit your needs. How much power are you trying to make?

There's a pretty nice "turbo calculator" type of thing here:

http://not2fast.wryday.com/tur...shtml

You'll need to know quite a bit about your power goals, and your setup to make it work.
I've played around with this since I found it a few days ago, and I believe it to be pretty accurate.

BlueShadow

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2LiterTurboSeR &raquo;</TD></TR><TR><TD CLASS="quote">
Is there any information I can provide anyone to help clear up any questions?</TD></TR></TABLE>

What year SR20DET are we talking about? and also what kind of turbo does it have stock and how much psi does the SR20DET in question have stock?

EDIT: I re-read your first post and it sounds like you have a factory SR20DE and not a factory DET? In addition to the stuff above a dyno chart of a stock SR20DE might help too. If you also know it the tranny % loss so I can calculate flywheel HP instead of WHP.



Modified by BlueShadow at 12:33 PM 11/11/2005

.RTErnie

put a GT30R on it and you wont be disappointed. /thread.

2LiterTurboSeR

Stock dyno sheet with K&N Filter:



I can't seem to find the exact drivetrain loss, but it seems to be around 15%. You are also correct in noticing I have an SR20De, which is 9.5:1 compression over 8.8:1 of the SR20DET I believe.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RTErnie &raquo;</TD></TR><TR><TD CLASS="quote">put a GT30R on it and you wont be disappointed. /thread.</TD></TR></TABLE>

Well when you give me a thousand dollars to play with, I'll take you up on that idea

BlueShadow

err you have a bigger dyno? I need to be able to read the numbers.

degradated

Sorry to break it to you, but you can't determine when a turbo will spool up by looking at the compressor map.

2LiterTurboSeR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by degradated &raquo;</TD></TR><TR><TD CLASS="quote">Sorry to break it to you, but you can't determine when a turbo will spool up by looking at the compressor map.</TD></TR></TABLE>

Nice to know, but don't reply to the topic if you don't have anything to help answer my questions.

http://www.daht.com/hyphen/ima...5.jpg
^^^ Bigger dyno chart

BlueShadow

sweet, that'll work. I'm doing something up right now in a QuattroPRO spreadsheet. I dont know how accurate it would be though. It'll be a while before it's ready to be posted up. For now I think you should contact TheShodan, since he's got a lot of experience with turbo selections.

BlueShadow

Forgot to ask you what the manufactureres claimed HP as for your year motor.

2LiterTurboSeR

Claimed flywheel horsepower is 140.

BlueShadow

ok cool, I'm getting close to finishing up that spread sheet. I'll post screenshots probably in the next half hour.

BlueShadow

Ok that skyliner guy might actually be right. I just finished up plotting the numbers using the info I know and it came out close to his. You should save my pic and compare it to skyliners and maybe even show TheShodan and see how far off we were. The hardest part was trying to predict what the boost pattern would be. So I pretty much had to guess. I dont think you mentioned how much HP or boost you were planning on running. I might be able to do up another chart based on your HP/boost goals.

BlueShadow

forgot to mention that using my chart then at the 6500 RPM you'll probably have around 300-330 HP.

2LiterTurboSeR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BlueShadow &raquo;</TD></TR><TR><TD CLASS="quote">forgot to mention that using my chart then at the 6500 RPM you'll probably have around 300-330 HP.</TD></TR></TABLE>

That chart is impressive, pretty close to what skylinder had to say over on the SR20Forum. I'll PM TheShodan and have him look at this and see what he thinks.

If I'm reading the chart right, the end of the chart is 15 psi? I had intentions of running 15-20 psi depending on what type of gas is in the tank. I'll probably be revving the engine so 7500-8k rpm's so I'm not sure how to calculate how much more power would be made at 20 psi and 8k rpm's.

BlueShadow

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2LiterTurboSeR &raquo;</TD></TR><TR><TD CLASS="quote">

That chart is impressive, pretty close to what skylinder had to say over on the SR20Forum. I'll PM TheShodan and have him look at this and see what he thinks.

If I'm reading the chart right, the end of the chart is 15 psi? I had intentions of running 15-20 psi depending on what type of gas is in the tank. I'll probably be revving the engine so 7500-8k rpm's so I'm not sure how to calculate how much more power would be made at 20 psi and 8k rpm's.</TD></TR></TABLE>

You can just do a little guessing based on what the HP and RPM's were at the last few hundred RPMs of that stock dyno you posted. I'm gonna go and do up another chart using 20 psi as the limit. BTW you are right, the last dot is 15 psi at 7000 RPMs.

EDIT: on second though I'm not gonna do a chart of 20 psi. I'm trying to work on the formulas cause something doesn't look right.



Modified by BlueShadow at 5:03 PM 11/11/2005