DIY Turbo Discussion greddy on a 1.8? homebrew kit?

I want your spool data!

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Old 10-07-2008, 12:22 PM
  #61  
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OK whiny biotches. I'll log a 4th gear. Sheesh, just cause I'm really an ignorant newb that doesn't know that 4th is 1.1 or even noticed that was asked for...

Do you really think that my pull up a 12% grade with the AC on, a passenger and a trunk full of phone books was what helped?!? LOL

My car is pig heavy though. C package with hard and soft top + my 200lbs of "added lightness"!


EDIT- OK made 3 4th gear pull see my earlier post to compare 4th to 5th. Lost 100-200 rpms of spool low to high. Happy now? I'm friggin depressed...

Actually I'm still in the cluster of 2554's and 2560's, just at the high end of it vs. the middle. Still a happy boy!

1psi = 1863
2psi = 2060
3psi = 2225
4psi = 2456
5psi = 2549
6psi = 2733
7psi = 2880
8psi = 2990
9psi = 3090
10psi = 3190
11ps = 3250

Last edited by cueball1; 10-13-2008 at 09:57 PM.
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Old 10-07-2008, 01:55 PM
  #62  
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I was curious about the effect of gear selection on spool so I logged some pulls at lunch today in 2nd through 5th gear. All were started from ~2000 RPM with very light throttle (constant speed) before WOT.

I expected to see slower build in lower gears of course, but the effect is more than I thought it would be. Here is the resulting graph submitted for your consideration. I have added trend lines since the 5th and 4th gear data are noisy. The trend is pretty clear, especially in the lower gears.

So the point is, everyone needs to do this in the same gear ratio because otherwise the data is noticeably skewed. And no power braking either
Attached Thumbnails I want your spool data!-gear-versus-spool.gif  

Last edited by ZX-Tex; 10-07-2008 at 04:44 PM.
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Old 10-07-2008, 03:55 PM
  #63  
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I updated my original post on page 1 with a pull starting at 2000 rpms.
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Old 10-07-2008, 04:21 PM
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So I have a proposition based on Paul's comment regarding pulls starting at low RPMs not reflecting a real-world pull. These tests are more a measure of at what RPM a turbo begins building boost at. And the trend as expected shows that in general that smaller turbos build boost at lower RPMs.

So what about a scenario that is more real-world? What if we try some spooling runs where we go from steady state RPM (speed) to WOT starting at a higher RPM that would be more typical of what one would do while driving? This would show how well the turbo responds. It looks like most everyone is making good boost by 3500 RPM so I think that is a good starting point.

If we really want to make it interesting, we could throw time into the equation and plot on three axes. I'll do the plotting. The MS logs at roughly 10th sec intervals so the spool should be able to be caught. Adding time would show some things like additional power (more power means faster RPM build up), and differences in differential gearing.

So I'll throw this out there. Format:
Engine:
Turbo:
Manifold:
Downpipe Size/Style:
Exhaust Size: 2.5"Exhaust Components:
Intercooler Core Size:
Intake Manifold:
Headwork:
Engine Management:
Other Spoolin' Helpers/Hurters:

4th gear pull at 3500 RPM (start from a steady-state speed, no RPM change for a few seconds, go to WOT)

RPM Boost (PSI) Time (secs)

Mods feel free to start another thread if you think this is getting too far off the mark. AND, please use space delimited text, no equals signs or units in the actual log data. This makes it easier to import into Excel.
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Old 10-07-2008, 04:33 PM
  #65  
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just do a pull from 2K in your 1:1 gear on a flat road. the end. better yet. all you suckers strap on a dynojet with boost logging, we'll directly compare our runs vs torque output.
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Old 10-07-2008, 04:37 PM
  #66  
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Yeah, I don't think you'd get much more from redoing this. Power curves (tq/hp) would draw a complete picture of the setup.
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Old 10-07-2008, 04:38 PM
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Well we already did that right? I'm talking about taking it a step farther. Of course if no one else is interested...

I do not have any dyno run data, at least not yet... But I agree that would be a great thing to look at. This shows the small turbos spool sooner, but it would be good to see how much less power they make once they achieve boost. Wouldn't everyone need to do pulls at the same target boost level though for that to work? And use the same type of dyno at uncorrected RWHP?
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Old 10-07-2008, 04:48 PM
  #68  
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Yeah, It's like Tim's new twin turbo setup might spool later than mine, but our torque output below 3K was nearly identical.

Sam thing with me and Samnavy's setup. He has a T25 that spools faster than my T3, yet I'm making more torque throughout with less boost.

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Old 10-07-2008, 07:01 PM
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If i'm cruising at 3500 and mash the gas in either of my cars high boost is pretty instantaneous
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Old 10-07-2008, 07:13 PM
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+ 1 for Pauls comment. When I hit full throttle at mid to high rpms it's less than 1 second according to MS logs to full boost. It would be hard to find real world significance between a spool of .74 and .92 seconds even though statistically it's 20%. Functionally I think it's pretty irrelevant.
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Old 10-07-2008, 08:18 PM
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Yes- it would require similar steps for power runs BUT regardless it would further illustrate the efficiency of the system. It would illustrate what you get for the boost at any given point. It would be a good reference for somebody building a turbo Miata IMO.
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Old 10-07-2008, 09:40 PM
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OK agreed. I ran a log today on the way home going from cruise to WOT at 3500 and boost was pretty instantaneous, faster than I would have guessed.

Agreed on the value of the HP plots for the different setups. I have looked at many of the past plots to see what I can expect at X boost with turbo A. Very helpful. And, now that we have this great spool comparison plot we can compare spool times for Turbo A versus Turbo B as well, to assess 'streetability' for example.

But it would still be nice to compare torque or power levels, but correct or normalize them somehow for the different boost levels. That would make a comparison of two different turbo sizes comparable even if they are not running at the same PSI. So, what about something like a plot of torque per psia (not psig AKA boost) at a function of RPM? So, for example, take two Miatas: Car #1 with a 'big' turbo, Car #2 with a 'small' turbo
Car #1 at 9 psi of boost (24 psia) is making 210 ft/lb torque at 4000 RPM
Car #2 at 12 psi of boost (27 psia) is making 220 ft/lb of torque at 4000 rpm.
Therefore Car #1 is making 210/24 = 8.75 ft/lb per psia
and Car #2 is making 220/27 = 8.14 ft/lb per psia

So it shows that even though Car #2 is making more torque, when corrected as shown above to torque per psia, one can see the efficiency advantage of the bigger turbo. It is making roughly 7% more torque per psia. It is not exactly a perfect comparison but at least it normalizes the data a bit. Maybe a correction factor for 1.6L versus 1.8L could be thrown in as well. This is just at one datapoint of course. The normalized data could be plotted over the RPM range.

OK not trying to be difficult here, just throwing it out there for consideration.

Last edited by ZX-Tex; 10-07-2008 at 09:51 PM.
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Old 10-07-2008, 11:14 PM
  #73  
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I sure would like to see spool data for a 2554 on the current FMII manifold. Guess that isn't likely to happen on this forum.
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Old 10-07-2008, 11:19 PM
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Originally Posted by ZX-Tex
OK agreed. I ran a log today on the way home going from cruise to WOT at 3500 and boost was pretty instantaneous, faster than I would have guessed.

Agreed on the value of the HP plots for the different setups. I have looked at many of the past plots to see what I can expect at X boost with turbo A. Very helpful. And, now that we have this great spool comparison plot we can compare spool times for Turbo A versus Turbo B as well, to assess 'streetability' for example.

But it would still be nice to compare torque or power levels, but correct or normalize them somehow for the different boost levels. That would make a comparison of two different turbo sizes comparable even if they are not running at the same PSI. So, what about something like a plot of torque per psia (not psig AKA boost) at a function of RPM? So, for example, take two Miatas: Car #1 with a 'big' turbo, Car #2 with a 'small' turbo
Car #1 at 9 psi of boost (24 psia) is making 210 ft/lb torque at 4000 RPM
Car #2 at 12 psi of boost (27 psia) is making 220 ft/lb of torque at 4000 rpm.
Therefore Car #1 is making 210/24 = 8.75 ft/lb per psia
and Car #2 is making 220/27 = 8.14 ft/lb per psia

So it shows that even though Car #2 is making more torque, when corrected as shown above to torque per psia, one can see the efficiency advantage of the bigger turbo. It is making roughly 7% more torque per psia. It is not exactly a perfect comparison but at least it normalizes the data a bit. Maybe a correction factor for 1.6L versus 1.8L could be thrown in as well. This is just at one datapoint of course. The normalized data could be plotted over the RPM range.

OK not trying to be difficult here, just throwing it out there for consideration.
+93432343243e33

I was thinking the same thing when I first opened this thread. It would be "neat" to be able to see the difference between a 2554 and a 2560 for example, rather than "just get the 2560, more power, spool's bout' the same".
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Old 10-08-2008, 12:21 AM
  #75  
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Here.
Ignore the ringing.
The extra boost up top was from a change in the boost map.
Attached Thumbnails I want your spool data!-2nd-gear-spoolup.gif  
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Old 10-11-2008, 08:25 PM
  #76  
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New data. Fixed a small vacuum leak and reflashed to HR10G + retune. Pretty impressive.

Engine: '94 1.8 liter, OEM 150k longblock
Turbo: GT2554R
Manifold: BEGi Cast "Directed Pulse" (standard S2/S3) with EGR
Downpipe Size/Style: BEGI 3" SSSG
Exhaust Size: 3"
Exhaust Components: BEGi DP, custom 3" midpipe with metal-core 3" cat, 3" Enthuza catback
Intercooler Core Size: 27x6.5x2.5"
Intake Manifold: Stock
Headwork: OEM
Engine Management: MSPNP HR10G
Other Spoolin' Helpers/Hurters: Toyota COPs, MS EBC

FIFTH GEAR PULL: (6-speed 1:1)

RPM Boost
1500 0psi (actually logged 0psi :P)
1664 1.015psi
1767 2.176psi
1907 3.047psi
2027 4.063psi
2281 4.788psi
2305 5.224psi
2538 6.094psi
2647 6.820psi
2672 7.545psi
2758 7.981psi
2825 8.997psi
2924 10.157psi
3019 11.028psi
3087 12.044psi
3259 14.076psi
3439 14.801psi
3549 15.962psi
3648 16.688psi

Attached a chart of my old spool vs. my new spool.
Attached Thumbnails I want your spool data!-hr10gspool.jpg  

Last edited by Savington; 10-11-2008 at 08:39 PM.
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Old 10-11-2008, 08:43 PM
  #77  
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Was it colder out?
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Old 10-11-2008, 09:35 PM
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I think the first log was cooler by about 10-15 degrees. 70 degree ambient temps today when I took that.
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Old 10-13-2008, 04:53 AM
  #79  
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still needs some tweaking but this is the result from tuning ebc tonight with ambient temps of 65F. So far I like it much more than the gt2860rs. Much more torque much earlier.

Engine: 1994 1.8
Turbo: gt2560r
Manifold: BEGi Cast "Directed Pulse"
Downpipe Size/Style: Begi separated gas 2.75"
Exhaust Size: 3"
Exhaust Components: 3" metalcore cat & Magnaflow Muffler
Intercooler Core Size: Begi #2
Intake Manifold: Stock
Headwork: none
Engine Management: MSPnP
Other Spoolin' Helpers/Hurters: none
Trans & Rear End Ratio: 5-speed, 4.10 torsen
Rear tire size: 225/45/15

FOURTH GEAR PULL:

RPM Boost(psi)

2099 0.290
2230 2.031
2336 3.192
2447 4.353
2582 5.514
2688 6.530
2786 7.836
2883 8.851
2960 10.157
3092 12.044
3193 13.060
3250 14.221
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Old 10-13-2008, 05:04 AM
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@johndoe: Wow, that's good spool. Can't wait to upgade my cat and catback to 3".
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