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Old 11-09-2007, 03:24 PM   #1
Scooby South
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Thumbs up VF39 VS. VF43 Revisted

Well...Let me just say..that a VF43 is way stronger than my old VF39...
to the point where I will have to retune the boost levels...

My Stock VF39...was tuned to 20.5 lbs of boost....Falling off considerably after 4800 RPMs. down to about 11 psi and yes it had the famous crack, which is why I upgraded anyways........it would start to spool about 1800 rpm..(I had a Full race SCCA BSP tune, to be able to spool as soon as I could)...Full boost would be around 2300 RPM and it wouldn't hold boost worth a crap above 4800 RPM.......

Now:

It still goes on boost about 2000 RPM...so it moved about 200 RPM to the right...which is still decent on my BSP Tune with UTEC....but Now it holds boost to like almost 6000 RPM....then it only drops off to about 15.5 lbs...so its stronger on top...
It actually went to 25 PSI the first couple of pulls(pulling timing)...so I had to reduce Boost to have it a ROCK HARD 20.5 lbs...from the start now...PULLS STRONG...

I am probably going to have to have a retune done... to optimize everything...but before...My tune was 326 AWHP...and 364 Torque...on stock vF39, Lightweight stock sized Crank pully, Divorced Wastegate Exhaust (No cats)..and a K@N Typhoon, Fuel Pump, UTEC...also had a Larger TMIC...so I am going to have to see how it compares to my 39 setup...Right now by the butt dyno...it feels stronger...and pulls harder...

BTW..this info is posted because I couldn't find a decent thread comparing the 39 to the 43....Hopefully..it will help some of you that are trying to make a decision on which turbo to go with ...a 39 or 43......

Thanks

Bill
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Old 11-09-2007, 04:43 PM   #2
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good to know ! let them know that the 43 has a bigger wastegate
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Old 11-09-2007, 05:31 PM   #3
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This is awesome information! I, too, have been looking for some decent comparisons of the 39 to the 43 (as I run a 43 on my FXT). I've been concerned that maybe it was not a better idea to have bought the 43 instead of the 39.

I was wondering if there were significant differences in regards to tuning the two.
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Old 11-09-2007, 05:43 PM   #4
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Quote:
Originally Posted by xdrian View Post
good to know ! let them know that the 43 has a bigger wastegate
Noted...Topspeed will probably be doing my re-tune...so Hopefully I will see some good numbers..

Quote:
Originally Posted by Fuquad View Post
This is awesome information! I, too, have been looking for some decent comparisons of the 39 to the 43 (as I run a 43 on my FXT). I've been concerned that maybe it was not a better idea to have bought the 43 instead of the 39.

I was wondering if there were significant differences in regards to tuning the two.
I don't think it will "tune" any different...just basically have dial in the boost....whereas before I had to throw timing at it to maintain anything up top..so it might affect that somehow...We will see after its all done.....I basically had to let the ECU relearn before I can go in and adjust Boost..right now...its still overboasting in 4th/5th gear..to like 24lbs....Now that I am thinking about it...It probably will affect the tune...at least on top....I will post the results after the re-tune ..

Bill
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Old 11-09-2007, 06:09 PM   #5
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Quote:
Originally Posted by Scooby South View Post
I don't think it will "tune" any different...just basically have dial in the boost....whereas before I had to throw timing at it to maintain anything up top..so it might affect that somehow...We will see after its all done.....I basically had to let the ECU relearn before I can go in and adjust Boost..right now...its still overboasting in 4th/5th gear..to like 24lbs....Now that I am thinking about it...It probably will affect the tune...at least on top....I will post the results after the re-tune ..

Bill
I have a Cobb AccessPORT and ProTUNE (along with a long laundry list of other mods) including a Perrin Boost Solenoid. I'm boosting pretty high in 4th and 5th. I think my target boost in the tune is supposed to be around 18, but I am up around 21 often.
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Old 11-09-2007, 08:09 PM   #6
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hmm, i might have to pick up one of these 43's if they are cheap enough....hmm...sell my 39 and just buy a 43...ftw? i'll wait for results, i have an ewg too so i don't know about gains over the 39 in that case
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Old 11-09-2007, 08:34 PM   #7
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Quote:
Noted...Topspeed will probably be doing my re-tune...so Hopefully I will see some good numbers..
their dyno reads crazy high
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Old 11-09-2007, 08:37 PM   #8
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their dyno reads crazy high
actually...it would be on our dyno....here in Jacksonville....Doug will just be doing the tuning.....

Bill
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Old 11-10-2007, 06:27 AM   #9
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I wonder if the VF39 was in good shape. Because usually VF39's don't taper that bad (to 11 psi). Anyway the VF43 is a superior design. Are the 326WHP 364lb/ft numbers done in the same dyno that is going to be retuned?
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Old 11-10-2007, 07:50 AM   #10
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Quote:
Originally Posted by Speed View Post
I wonder if the VF39 was in good shape. Because usually VF39’s don't taper that bad (to 11 psi). Anyway the VF43 is a superior design. Are the 326WHP 364lb/ft numbers done in the same dyno that is going to be retuned?
yes.....same dyno
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Old 11-10-2007, 07:59 AM   #11
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i'm definitely interested to see these numbers. thanks for this! i wonder how it would compare to say a super16g.

depending on your numbers, i might've found myself a new turbo to buy
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Old 11-11-2007, 12:56 AM   #12
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thats weird your boost fell off that much to 11 psi i have a wrx with the 39 and hold 18 psi to redline 21 midrange
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Old 11-11-2007, 11:16 AM   #13
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Quote:
Originally Posted by Speed View Post
I wonder if the VF39 was in good shape. Because usually VF39’s don't taper that bad (to 11 psi). Anyway the VF43 is a superior design. Are the 326WHP 364lb/ft numbers done in the same dyno that is going to be retuned?
Quote:
Originally Posted by bp03wrx View Post
thats weird your boost fell off that much to 11 psi i have a wrx with the 39 and hold 18 psi to redline 21 midrange

made me wonder too....I was changing the clutch out....and took a peak at the turbo....std crack in the wastegate...so i definatly think the turbo was on its way out...

Will keep you guys advised..
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Old 11-11-2007, 11:24 AM   #14
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I would like to see the two curves on top of each other
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Old 11-12-2007, 10:44 AM   #15
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Can you post screenshots of your utec map? I'd like to see what your timing/wastegate maps are like... As I am tuning my car for BSP as well... And I get full spool on my 39 by 2900rpms with a similar setup... So I'd like to see how you are getting full spool by 2k rpms.
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Old 11-12-2007, 11:06 AM   #16
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oh you can definately beat 2900 rpm. I can make 18 lbs on my 205 with my pnp 39 by 3K rpms
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Old 08-31-2013, 04:14 PM   #17
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Quote:
Originally Posted by Scooby South View Post
My Stock VF39...was tuned to 20.5 lbs of boost..........it would start to spool about 1800 rpm..(I had a Full race SCCA BSP tune, to be able to spool as soon as I could)...Full boost would be around 2300 RPM and it wouldn't hold boost worth a crap above 4800 RPM.......

Thanks

Bill


I know this is a 6yr old thread, but hes a moderator and I would very much appreciate proof, dyno, video or something. 20.5 psi @ 2300rpm spool on a vf39..? A pic of the unicorn standing next to it seems appropriate also.





.

Last edited by 95ONE; 08-31-2013 at 04:22 PM.
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Old 09-05-2013, 11:50 PM   #18
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Quote:
Originally Posted by 95ONE View Post
I know this is a 6yr old thread, but hes a moderator and I would very much appreciate proof, dyno, video or something. 20.5 psi @ 2300rpm spool on a vf39..? A pic of the unicorn standing next to it seems appropriate also.
.
To me this thread reads as if the OP had a crap tune or setup and got a better one. Had nothing to do with the turbo itself being that much better of a turbo design.

And I too would love to see the unicorn and jesusspool.
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Old 09-01-2013, 09:33 AM   #19
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its on a 2.5L...not that unheard of
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Old 09-01-2013, 04:48 PM   #20
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its on a 2.5L...not that unheard of

Fine.. show me.
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Old 09-01-2013, 07:25 PM   #21
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Lol. .
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Old 09-05-2013, 11:09 PM   #22
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I wish my 16gxt spooled like that
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