Welcome to the North American Subaru Impreza Owners Club Saturday December 20, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 10-15-2002, 02:29 PM   #1
Austin
Scooby Guru
 
Member#: 7089
Join Date: May 2001
Chapter/Region: NWIC
Location: Western Wa
Default VF34 vs. VF29 spool up rpm

The best datalog I could find of my VF29 shows it coming to 14.7psi boost at ~ 3080rpm. I remember the VF29 spooling a hair quicker than that, I just couldn't find a datalog to show it.

In the few datalogs I've done so far with the VF34, it spools to 14.7psi boost at ~ 2950 rpm.

All datalogs show 4th gear runs on my car.

I like the VF34.

VF34 vs. VF29 vs. stock turbo for 3rd gear spooling time soon to follow.

* Registered users of the site do not see these ads.
Austin is offline   Reply With Quote
Old 10-15-2002, 05:50 PM   #2
Bailey
Scooby Specialist
 
Member#: 12572
Join Date: Nov 2001
Chapter/Region: NWIC
Location: Portland Oregon
Vehicle:
2004 STi
35R is enough

Default Thanks Austin

OMG! Actual data! Very nice. Do the data logs match your "seat of the pants" impressions of these three turbos (stock, 29, 34)?

As another point of comparison - with no hard data mind you - Goodfinder has recently reported that his new SR30 spools even faster than his old VF29. I think you need one of these as well.

Bailey
Bailey is offline   Reply With Quote
Old 10-15-2002, 07:34 PM   #3
Red Rocket
Scooby Specialist
 
Member#: 10507
Join Date: Sep 2001
Vehicle:
'04 Ex STi Owner
'97 4Runner

Default Weeeeeeeee......

I finally installed my VF29 today (thanks again Austin). I see about 14+ psi (spike) by 3150 RPM's in 4th gear, which settles to the normal 13.5 psi. This is with:

- STOCK BOOST CONTROL (plus 3/16th's mod)
- ATR uppipe (large and poor spooling)
- Scoobysport downpipe
- Stock 3rd cat
- Stock catback
- Various DIY intake mods (velocity stack, spaced fog light, hacked grille, snorkle in place, K&N)

I also have an exhaust cutout intalled before the third cat, but I have yet to test it with this turbo. I should be switching to a TXS uppipe soon, getting a silicone intake pipe, and going to some other sort of boost control, all of which *should* help my spool.

Kevin
Red Rocket is offline   Reply With Quote
Old 10-15-2002, 07:39 PM   #4
Austin
Scooby Guru
 
Member#: 7089
Join Date: May 2001
Chapter/Region: NWIC
Location: Western Wa
Default

Yup, all that stuff will help your spoolup. My runs were with short ram cone filter, silicon induction pipe and intercooler hoses, ported TB, no TGV's, uppipe, catless exhuast.
Austin is offline   Reply With Quote
Old 10-15-2002, 08:08 PM   #5
jimb
Scooby Specialist
 
Member#: 9923
Join Date: Sep 2001
Vehicle:
2005 Legacy GT
RIP MBP WRX

Default

What are you using for boost control?

jb
jimb is offline   Reply With Quote
Old 10-15-2002, 08:17 PM   #6
Austin
Scooby Guru
 
Member#: 7089
Join Date: May 2001
Chapter/Region: NWIC
Location: Western Wa
Default

Most often a ball and spring MBC. For a while I used a dual stage MBC with a ball and spring and a bleed valve. I also used a couple differenct solenoids controlled by an RPM vs. MAP duty cycle map on the TEC3.
Austin is offline   Reply With Quote
Old 10-15-2002, 08:26 PM   #7
teiva-boy
Scooby Guru
 
Member#: 22825
Join Date: Aug 2002
Chapter/Region: NWIC
Location: Seattle, WA
Default

Austin your posting may have just changed my mind on buying your VF29. You better get some good datalogs for me Try and find the ones that you think had a lower spoolup time.
teiva-boy is offline   Reply With Quote
Old 10-15-2002, 08:36 PM   #8
driggity
Scooby Specialist
 
Member#: 7453
Join Date: Jun 2001
Chapter/Region: TXIC
Location: Grapevine, TX
Vehicle:
2005 Legacy GT Wagon
2006 LJ Rubicon

Default

Ok first of all I'm assuming that those MAP values are in kPa (I hope so, cause if not I'm completely lost) and the TPS values are just a voltage. If thats right then I think I understand the graphs, but I have a few questions. Is the scale for both time axis the same? Although I just looked at the graphs more carefully and this may not matter because your initial RPM was different, but that brings up another question. Does the fact that you hit full throttle while at different RPM matter or were you at a low enough RPM in both runs for this not to matter? It seems that the value for the VF29 might be off because of the fact that it appears as though you went WOT at about 2700-2800 RPM in that run as opposed to going WOT at about 2000 RPM in the VF34 run. Am I making any sense here or am I just being dumb?

edit: Sorry for the stream of consciousness there. I'll re-type it if it doesn't make sense.
driggity is offline   Reply With Quote
Old 10-15-2002, 08:41 PM   #9
Austin
Scooby Guru
 
Member#: 7089
Join Date: May 2001
Chapter/Region: NWIC
Location: Western Wa
Default

Quote:
Originally posted by driggity
Ok first of all I'm assuming that those MAP values are in kPa (I hope so, cause if not I'm completely lost) and the TPS values are just a voltage. If thats right then I think I understand the graphs, but I have a few questions. Is the scale for both time axis the same? Although I just looked at the graphs more carefully and this may not matter because your initial RPM was different, but that brings up another question. Does the fact that you hit full throttle while at different RPM matter or were you at a low enough RPM in both runs for this not to matter? It seems that the value for the VF29 might be off because of the fact that it appears as though you went WOT at about 2700-2800 RPM in that run as opposed to going WOT at about 2000 RPM in the VF34 run. Am I making any sense here or am I just being dumb?

edit: Sorry for the stream of consciousness there. I'll re-type it if it doesn't make sense.
Yes, the MAP values are in KPA. 101kpa = 1 atm = 14.7psi. TPS values are a voltage from a 5 volt sensor. My normal closed throttle voltage is .57 - .59, my normal WOT voltage is 3.91 or 3.93.

Yes, the VF29 graph isn't the best, because I go WOT too late... giving the VF34 an advantage. I'm cropping some good 3rd gear graphs now.
Austin is offline   Reply With Quote
Old 10-15-2002, 08:46 PM   #10
Austin
Scooby Guru
 
Member#: 7089
Join Date: May 2001
Chapter/Region: NWIC
Location: Western Wa
Default

Here are three graphs, a bit more on equal footing, for the stock turbo, VF29, and VF34.

The stock turbo was missing a few of the above mentioned airflow mods... namely TGV eliminator plates and Samco induction pipe.


Austin is offline   Reply With Quote
Old 10-15-2002, 08:48 PM   #11
Red Rocket
Scooby Specialist
 
Member#: 10507
Join Date: Sep 2001
Vehicle:
'04 Ex STi Owner
'97 4Runner

Default

Quote:
Originally posted by driggity
Does the fact that you hit full throttle while at different RPM matter or were you at a low enough RPM in both runs for this not to matter? It seems that the value for the VF29 might be off because of the fact that it appears as though you went WOT at about 2700-2800 RPM in that run as opposed to going WOT at about 2000 RPM in the VF34 run. Am I making any sense here or am I just being dumb?
That's very observant. Being at WOT longer from low RPM's usually results in peak boost at lower rpms. That figure I gave of 3150 rpm's is from going WOT at 2000 RPM. That graph of Austin's VF29 shows from no boost to target boost from 2800 to 3080 RPM......very good dynamic response.

You know, we're really splitting hairs on this VF29 vs. VF34 thing. The VF29 is only a couple years older, has the same size exhaust side, and a compressor that's rated at 10 hp less.

They should spool pretty much the same.

Kevin
Red Rocket is offline   Reply With Quote
Old 10-15-2002, 08:51 PM   #12
driggity
Scooby Specialist
 
Member#: 7453
Join Date: Jun 2001
Chapter/Region: TXIC
Location: Grapevine, TX
Vehicle:
2005 Legacy GT Wagon
2006 LJ Rubicon

Default

Quote:
Originally posted by Austin
Yes, the VF29 graph isn't the best, because I go WOT too late... giving the VF34 an advantage.
Yeah, thats pretty much what I was thinking. I just wasn't thinking that when I started typing hence the useless question about whether the time scales were the same. That question may be important on the 3rd gear graphs though as for some people not only the rpm at which full boost is made but the time it takes to make full boost after you go WOT may be important. Actually that would be interesting to see both at low rpm (~2000) and somewhere in the middle of the power band (maybe 4000 or so RPM).
driggity is offline   Reply With Quote
Old 10-15-2002, 08:55 PM   #13
Austin
Scooby Guru
 
Member#: 7089
Join Date: May 2001
Chapter/Region: NWIC
Location: Western Wa
Default

I've got a million datalogs I could post, but it's pretty time consuming going back through them all finding good graphs...

As far as lag...

On a quickness scale, if the stock turbo is a 10 and the VF34 is a 1, the VF29 is about a 4. It's definitely not as laggy as the 34, but not as instantaneous as the stock turbo. IE, at 4000 rpm cruising along, go WOT, the stock turbo may take .3 seconds to come up to max boost, the 29 may take .6 seconds, and the 34 may take .8 seconds. None of them are really suffer from big-turbo "laggy" (at least on my car).

The 34 is definitely the fastest of these three.
Austin is offline   Reply With Quote
Old 10-15-2002, 09:00 PM   #14
driggity
Scooby Specialist
 
Member#: 7453
Join Date: Jun 2001
Chapter/Region: TXIC
Location: Grapevine, TX
Vehicle:
2005 Legacy GT Wagon
2006 LJ Rubicon

Default

Quote:
Originally posted by Austin
I've got a million datalogs I could post, but it's pretty time consuming going back through them all finding good graphs...
Yeah, I'd imagine so and since I probably won't be doing a turbo upgrade anytime soon it doesn't really matter to me. Its just interesting stuff to see. And something to keep in mind if you ever want to spend a bunch of time swapping turbos and datalogging for the good of the I-club community
driggity is offline   Reply With Quote
Old 10-15-2002, 09:40 PM   #15
Austin
Scooby Guru
 
Member#: 7089
Join Date: May 2001
Chapter/Region: NWIC
Location: Western Wa
Default

Here are a few more...

You can see the VF29 is quicker to come back on boost than the 34, but not as quick as the stock turbo.



Austin is offline   Reply With Quote
Old 10-16-2002, 04:57 AM   #16
teiva-boy
Scooby Guru
 
Member#: 22825
Join Date: Aug 2002
Chapter/Region: NWIC
Location: Seattle, WA
Default

Okay, I havent changed my mind Thanks Austin see you next month
teiva-boy is offline   Reply With Quote
Old 10-16-2002, 08:19 AM   #17
is2scooby
Scooby Specialist
 
Member#: 19851
Join Date: Jun 2002
Location: Honolulu, HI
Vehicle:
02 WRX
Aspen White/12.75@105.67

Default

Any thoughts on how far behind the good ol' VF30 would be spooling compared to the turbos here?
is2scooby is offline   Reply With Quote
Old 10-16-2002, 09:11 AM   #18
Austin
Scooby Guru
 
Member#: 7089
Join Date: May 2001
Chapter/Region: NWIC
Location: Western Wa
Default

The vf30 *should* be a bit later to spool than the 34, but I have no experience with it.
Austin is offline   Reply With Quote
Old 10-17-2002, 08:45 AM   #19
is2scooby
Scooby Specialist
 
Member#: 19851
Join Date: Jun 2002
Location: Honolulu, HI
Vehicle:
02 WRX
Aspen White/12.75@105.67

Default

Thanks!
is2scooby is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
V39 vs v30, spool up vs HP & torque manxaru Built Motor Discussion 4 02-20-2008 11:12 AM
Wich of these turbo spools up fastest: TD05, VF24, VF28, or VF29? bruce cohen Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 16 06-21-2003 03:22 PM
VF29 vs VF35 spool up QA Guy Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 4 04-16-2003 07:37 PM
High RPM spool up? nerrad5 Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 3 10-09-2002 02:50 AM
Will less fuel in the lower RPM range bring on faster spool-up? 2OHOH2WRX Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 10 05-27-2002 12:11 AM


All times are GMT -4. The time now is 04:09 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.