Does a VF52 'spool' slower than VF40? Take a look

**dmp** · #1: 09-10-2010, 05:14 PM

Looks pretty darn close to me.

Screen capture of my dyno; when their machine prints, it skews the RPM range for some reason.

Standard caveat - this machine reads about/at least 5% lower than most other mustang dyno...and 15% lower than most dynojets.

**Legend** · #2: 09-10-2010, 07:42 PM

You don't have boost curves posted, but assuming that tq follows boost pretty closely it looks like the VF52 is spooling ~150rpm slower than the VF40 from 2k-3krpms. Not an insignificant difference really.. but the VF52 powerband is so much sweeter and that's why a VF52 upgrade has so little downside. Nice.

**GTTuner** · #3: 09-11-2010, 09:19 AM

What are your mods? You got 30hp and 25ftlb, looks nice.

**praedet** · #4: 09-11-2010, 10:42 AM

What gear...

150 in 3rd is 300 or more in 2nd, 4-600 in 1st...

**dmp** · #5: 09-11-2010, 05:14 PM

that was 3rd. First gear? I can tell no difference. 150rpm is nothing. Even 500rpm is nothing. The 52 is running +5 psi than the 40 was.

Will likely re-tune; tuner played it...VERY safe.

**Legend** · #6: 09-11-2010, 05:38 PM

Quote:

Originally Posted by dmp

150rpm is nothing. Even 500rpm is nothing.

That is a matter of opinion. At some point as you delay and continue to delay power it becomes intolerable. Everyone has their own tolerance. Yours is apparently way past 500rpms. 500rpms later than a VF40 in 3rd would be too late for me, personally. I'm at around ~400rpms later than a VF40 on my current setup.

Praedet and I each used to have VF52 so we know it's a great turbo, BTW.

**dmp** · #7: 09-11-2010, 05:48 PM

you can honestly tell a 100rpm difference? crazy!

**whitetiger** · #8: 09-11-2010, 06:18 PM

on the road the difference is small, but in a autox event for example in a tight part of the couse where power in the 2000-3000 rpm band is needed, that small difference isnt so small anymore.

**LosAngelesLGT** · #9: 09-11-2010, 08:20 PM

Quote:

Originally Posted by dmp

that was 3rd. First gear? I can tell no difference. 150rpm is nothing. Even 500rpm is nothing. .

Right and 1000rpm is nothing... 50,000rpm is nothing... one MILLION rpm is nothing.

I disagree! 500rpm is a LOT of difference in lag. It is a TITANIC difference in DD turbo for squirting around short, tight areas. Not really looking to wind my car out (hence no 20g). Indeed, it is apparent that the vf40 is not only spooling faster, it is hitting peak power faster. Is the vf40 making more power at the same rpm? Well no, of course not.

**rao** · #**10:** 09-12-2010, 09:16 AM

Quote:

Originally Posted by LosAngelesLGT

Right and 1000rpm is nothing... 50,000rpm is nothing... one MILLION rpm is nothing.

I agree with this. Spool, lag and throttle response are irrelevant.

**LittleBlueGT** · #**11:** 09-12-2010, 10:08 AM

That graph looks about right to me.

Try logging a VF40 vs VF52 in 1st gear, the difference grows a bit.

Still a very good upgrade, with not much of a downside, although it DOES spool slower!

**dmp** · #**12:** 09-14-2010, 07:27 AM

are some of us confusing boost threshold with lag? 100rpm takes about .0001 seconds. (shrug)

**LosAngelesLGT** · #**13:** 09-14-2010, 08:30 AM

Quote:

Originally Posted by dmp

are some of us confusing boost threshold with lag? 100rpm takes about .0001 seconds. (shrug)

^You can go from zero to redline in first gear less than a hundredth of a second? My hero!

[/sarcasm]

I understand that you meant it as a matter of perspective but it is meaningless to claim 100rpm takes no time. 10,000rpm does NOT take .01 second. (It takes about 10x as long as 10rpm and about 10 times less long than 1000rpm assuming the same rate of acceleration.)

Even 10rpm takes time and you can bet your ass that IRL and Indy teams work out things like that with telemetry.

Is 100rpm noticeable in typical daily driving or even a dramatic change at the drag-strip? Definately no, however, a guy like WHITETIGER or Kief notice on a short tight course? I'm betting not only would they notice, they might even run some logs wondering why the car feels just a little off.

Im betting LBGT would notice something like that too (as would most of the LOGMAFIA)

EDIT: Op I am not picking on you, if you must know your 52 is spooling faster than my 39

**dmp** · #**14:** 09-14-2010, 12:19 PM

(sigh). Aight then.

**BLKGT5** · #**15:** 09-15-2010, 08:28 AM

Could be my tuning, but my VF52 spools up slower than my VF40 did for sure or maybe I'm feeling so much more power flood in than before on/off effect. No logs with me at work, but here's my two cents.

Off the top of my head and butt dyno, here the power band I've noticed.

VF40 3200 - 5300 range
VF52 3800 - 6000 range