T25 boost/spool plots? 1.8 only please - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Reply
 
 
 
LinkBack Thread Tools
Old 08-22-2014, 11:59 AM   #1
Murderator
Thread Starter
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,192
Total Cats: 2,583
Question T25 boost/spool plots? 1.8 only please

Like the title says.
I've looked over the spool thread, and did a search for sr t25 threads, as well as did several searches on google.

Does anyone have some good plots, or screen shots of MLV, showing what the boost onset looks like? Ideally from 2k rpm on, because nothing frustrates me more than seeing stupid plots started at 3k or higher.

The trend I've noticed is it will build at least a couple psi by 2-2.5, and progressively/linearly build up to peak at around 3.5-3.6, hold the torque til 5, then start tapering. I want to make sure that's the norm.

This is like the oldest one of the most common turbos on here, so post up whatcha got

Last edited by 18psi; 08-22-2014 at 01:19 PM.
18psi is offline   Reply With Quote
Old 08-22-2014, 01:04 PM   #2
Senior Member
iTrader: (2)
 
Join Date: Mar 2014
Location: Meridian, Mississippi
Posts: 637
Total Cats: 42
Default

I can't help you here, but I sypathize on the dyno plots starting at 3,000 or higher. Had this happen on one of my cars, told the dyno dipshit I wanted from 2,000 to 8,000 and he started the runs at around 3,500. I didn't realize while he was doing the runs, and the car was heated up substantially by the three runs he did so I didn't want to redo them. Really pissed me off.

Keith
Twodoor is offline   Reply With Quote
Old 08-23-2014, 08:06 PM   #3
Junior Member
 
Join Date: Feb 2014
Location: Chicago, IL
Posts: 95
Total Cats: 1
Default

I have a t25 build in the works, I am just having problems with my megasquirt. However seeing some spool data is cool just for grins.
AdrianD2 is offline   Reply With Quote
Old 08-24-2014, 11:41 AM   #4
Elite Member
iTrader: (13)
 
Join Date: Dec 2006
Location: Taos, New mexico
Posts: 5,703
Total Cats: 237
Default

Mine behaves very similar to how you described. Typically 2-4psi really quick, as long as you are above 1800 rpm or so. Then it kind of holds that, and rips up to 12psi by 3800 rpm or so and gives you a nice seat of the pants feel.

Mine is also at high altitude, so I assume it's quite a bit laggier than most of these setups at sea level.

I don't have any good boost plots, but heres a virtual dyno plot around 10psi.



much linear, very wow, so amaze. It's fun as hell and I wouldn't be building a motor if the thing didn't consume oil . I got it to hold boost better as well, so the above plot is just an example. You could definitely hold over 200whp to redline with it, probably more like 230-240whp at sea level with e85.
Fireindc is offline   Reply With Quote
Old 08-24-2014, 01:29 PM   #5
Murderator
Thread Starter
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,192
Total Cats: 2,583
Default

Nice. Thanks dude. Yeah, so far I like what I see
18psi is offline   Reply With Quote
Old 08-25-2014, 12:08 PM   #6
Elite Member
iTrader: (3)
 
concealer404's Avatar
 
Join Date: Aug 2011
Posts: 8,465
Total Cats: 782
Default

This what you're looking for?

It's spooling faster now.... there's been more timing added, and it's running more boost.

Holding better up top now as well. Still does 12psi at 7000rpm.


It's fun. Especially with total **** tires making it super drifty. Kindof fun to mash it in front of your buddy from a 20mph roll in 2nd gear and smoke him out.

[
concealer404 is offline   Reply With Quote
Old 08-25-2014, 12:15 PM   #7
Murderator
Thread Starter
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,192
Total Cats: 2,583
Default

Yes.

I was just admirin that in the Horton hears a HOO thread.

Looks like a really fun daily driver powerband. I am kinda surprised at how boost sets in - while progressive and really linear/smooth, I kinda sorta expected the tiny little pea shooter to get to peak torque sooner.

I'm hoping with vvt + tubular mani + e85 I can somehow hit peak closer to 3k, but we'll see (I'm working with 2.5" exhaust so might not be possibru)
18psi is offline   Reply With Quote
Old 08-25-2014, 12:19 PM   #8
Elite Member
iTrader: (3)
 
concealer404's Avatar
 
Join Date: Aug 2011
Posts: 8,465
Total Cats: 782
Default

I need to re-dyno it. Have a couple more changes to make. (3" downpipe, get VICS working, turn up the boost.) Currently, in real life, it hits a lot harder/earlier than that chart would suggest. 2nd gear mashing at 1500rpms means you're spinning tires HARD by 2500rpm.

I'll be able to get peak torque a bit lower. And much more of it.

I'd like to see 250wtq out of it. Will probably require a hell of a spike, but i ain't scurred.
concealer404 is offline   Reply With Quote
Old 08-25-2014, 12:49 PM   #9
Murderator
Thread Starter
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,192
Total Cats: 2,583
Default

DO IT!!!

you literally have everything in place to run ALLOFIT on this thing. if you're seriously gonna do it I'll send you a ton of Miataturbo.net stickers
18psi is offline   Reply With Quote
Old 08-25-2014, 12:54 PM   #10
Elite Member
iTrader: (3)
 
concealer404's Avatar
 
Join Date: Aug 2011
Posts: 8,465
Total Cats: 782
Default

I'm considering going to much larger injectors to run E85 for the lulz. Unfortunately it's a 9.0:1 motor so i'm losing out a little bit.


I'd laugh so hard if someone did the same built, but an 11:1 motor on E85. ALL THE SPOOL ALL THE TIME.
concealer404 is offline   Reply With Quote
Old 08-25-2014, 01:01 PM   #11
Murderator
Thread Starter
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,192
Total Cats: 2,583
Default

my next one, if and when I ever build it, will be at least 10:1. But leaning more toward 10.5

do you have e85 available? what injectors are in there now?

the stuff is awesome. you should do it.
18psi is offline   Reply With Quote
Old 08-25-2014, 01:03 PM   #12
Elite Member
iTrader: (3)
 
concealer404's Avatar
 
Join Date: Aug 2011
Posts: 8,465
Total Cats: 782
Default

Quote:
Originally Posted by 18psi View Post
my next one, if and when I ever build it, will be at least 10:1. But leaning more toward 10.5

do you have e85 available? what injectors are in there now?

the stuff is awesome. you should do it.
E85 is fairly common around here. (I'll be running the MX6 on it next season. 1000cc injectors on stock ECU FTW) Have the RX8 yellers in there now. They've got a little room to go, and will be just fine on pump gas if i bump the pressure a bit. (Still on stock FPR, was thinking about adding a Fuelab unit when i re-do the fuel lines for dual feed, because M-Tuned rail.)
concealer404 is offline   Reply With Quote
Old 08-25-2014, 01:06 PM   #13
Murderator
Thread Starter
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,192
Total Cats: 2,583
Default

I bet you can squeeze 250 out of them if you maxed em and maybe bumped the pressure up a tad.

off idle boost here we go
18psi is offline   Reply With Quote
Old 08-25-2014, 01:12 PM   #14
Elite Member
iTrader: (3)
 
concealer404's Avatar
 
Join Date: Aug 2011
Posts: 8,465
Total Cats: 782
Default

Quote:
Originally Posted by 18psi View Post
I bet you can squeeze 250 out of them if you maxed em and maybe bumped the pressure up a tad.

off idle boost here we go
250ftlbs, maybe.... it's already in the 240-250whp area right now, 86% duty cycle, running a bit more rich than necessary.
concealer404 is offline   Reply With Quote
Old 08-25-2014, 03:00 PM   #15
Senior Member
iTrader: (2)
 
Join Date: Mar 2014
Location: Meridian, Mississippi
Posts: 637
Total Cats: 42
Default

Quote:
Originally Posted by 18psi View Post
I bet you can squeeze 250 out of them if you maxed em and maybe bumped the pressure up a tad.

off idle boost here we go
With the returnless none pressure referenced 99 fuel pressure regulator system, around 220 WHP would be 100% duty cycle on E85... for a car with a FPR that has a boost reference line you could squeak out a few more at 100% duty. If you keep it down to 80% duty cycle you are limited to around 200 WHP... this is why I just swapped mine for 1000's from BEGi

Keith
Twodoor is offline   Reply With Quote
Old 08-25-2014, 03:23 PM   #16
Murderator
Thread Starter
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,192
Total Cats: 2,583
Default

Quote:
Originally Posted by Twodoor View Post
With the returnless none pressure referenced 99 fuel pressure regulator system, around 220 WHP would be 100% duty cycle on E85... for a car with a FPR that has a boost reference line you could squeak out a few more at 100% duty. If you keep it down to 80% duty cycle you are limited to around 200 WHP... this is why I just swapped mine for 1000's from BEGi

Keith
I think he's running the NA fuel system, but I see what you're saying.
Time for ID's
18psi is offline   Reply With Quote
Old 08-25-2014, 03:25 PM   #17
Elite Member
iTrader: (3)
 
concealer404's Avatar
 
Join Date: Aug 2011
Posts: 8,465
Total Cats: 782
Default

Correct. NA system on a 99 head.
concealer404 is offline   Reply With Quote
Old 08-25-2014, 04:12 PM   #18
Elite Member
iTrader: (2)
 
Join Date: Aug 2012
Location: Indianapolis
Posts: 3,325
Total Cats: 235
Default

The Prince of Bandaids doesn't need bigger injectors. Crank that fuel pressure to 120PSI!
thenuge26 is offline   Reply With Quote
Old 08-25-2014, 04:15 PM   #19
Elite Member
iTrader: (3)
 
concealer404's Avatar
 
Join Date: Aug 2011
Posts: 8,465
Total Cats: 782
Default

Quote:
Originally Posted by thenuge26 View Post
The Prince of Bandaids doesn't need bigger injectors. Crank that fuel pressure to 120PSI!

More pressure = better atomization, yes?
concealer404 is offline   Reply With Quote
Old 08-25-2014, 04:26 PM   #20
Murderator
Thread Starter
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,192
Total Cats: 2,583
Default

oh yeah, those ev6 rx8 injectors will love all the gape
18psi is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 12-13-2017 10:04 PM
Garrett Turbo, 1.8 Oil Pan, & Misc. Stuff nbdooey Miata parts for sale/trade 9 08-30-2017 10:50 PM
Noob to Miataturbo from MA JxPhan Meet and Greet 3 10-02-2015 03:17 AM
Low oil pressure after 1.8 swap and new turbo setup JesseTheNoob DIY Turbo Discussion 15 09-30-2015 03:44 PM
why is my car running like pewp? (tune/datalog) itsMikey MSPNP 3 09-28-2015 07:40 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 12:13 PM.