rostikk

Hi guys,

My current (relevant) mods are as follows: VF52, Process West TMIC, Grimmspeed EBCS, Perrin LW pulley, DW65c fuel pump, Supersprint DP 3"

I am looking for ways to decrease spool time on VF52. There is a number of small upgrades that contribute to this:
- Turbo blanket (done) - the impact is may be about -50rpms
- Lightweight crank pulley (done) - no impact on spool rpm, but slightly better rev
- Turbo inlet (under consideration) - impact claimed at -200-300rpms

Am I overlooking anything? Do you guys know of any other upgrades that would help decrease spool time?

Some posts say that Perrin Inlet improves spool by 200-300 rpms. Is this true?
Nate - I know you have one - what was your experience?

Thank you,
Ros

Patrick P931

I think you are missing the single most important parameter: the tune! ;)

When does your turbo spool up now? When do you get max boost?

What do your DBW tables look like?

There are many things to be said about the VF's but they don't spool slow imho.

:)
Patrick

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07 FXT
400+ ?

Superacerc

Also, a 3" catback (or anything higher flow than stock). Made my 18g hit much harder just switching out the catback from stock to the 3" CNT one. Also, the intake being capable of pushing more volume will help(similar to having a better inlet). I've got an AEM CAI coming in today. Those two things were actually holding my turbo back a bit. They are the last things i'm doing really to pick up a bit easier and faster.

The CAI requires more tuning to the Maf sensor but not much else.

__________________
e85 on a TD05-20g, suspension and brake upgrades.

rostikk

Thread Starter

My VF52 now reaches 16.5 psi between 3400-3700 rpm and stays at this pressure untill 5500 rpm. The tune is for 95 octane, as 98 is not widely available in my area.

If I could get it to that pressure at 3100-3400 this would have been great!

Are you sure cat-back will improve spool? I was told differently by my tuner...mainly that it would improve top-end power, but would have little impact before 5500 rpm, apart from more noise

Superacerc

I'd have to log a few runs and compare it to my earlier runs. It feels like it hits harder when the pressure comes in, im not sure about earlier spool. When I say hits harder, it feels like its less progressive on pressure buildup and makes all the pressure at once at a certain rpm.

Nate fisher would be a good one to ask, since im relating experience with an 18g pushing more volume.

__________________
e85 on a TD05-20g, suspension and brake upgrades.

dazzz

The stock cat back is plenty for the VF52 in my experience.

Spool aside, good tuners are able to make the car nice to drive when off boost too. What experience has lead you to want faster spool rostikk? What gear do you hit 16.5 psi?

rostikk

Thread Starter

Im on 4EAT... typically 3rd gear, I think.

Before going VF52 I was on TD04 with catless DP and tune. That combo spooled insanely fast, so I am now trying to move as close to it as possible

Dazzz - when do you typically reach 18psi?

dazzz

In my 3rd gear pulls starting low 2000rpm, I hit 16.5psi @ 3500 rpm and 19psi by 3700rpm. Personally, I would rather go CAI and not bother with the inlet, i got nice gains in response after the CAI.

Like Patrick P931 said, VF's aren't slow spooling turbos and a good tune is key. In my car, torque hits near instantly when needed... I applaud my tuner for that. Your mods should pretty much be a nice weapon, if you are unhappy with how it performs talk to your tuner and if they are of no help, then switch.

dazzz

I might add that I have had two SH9 Foresters now and both had the VF52 upgrade. The first Forester I had was manual, I almost took off the VF52 and put the TD04 back on cause I was so unhappy with the way it performed... seemed like I downgraded: slow spool, slow response, high fuel consumption... THEN I was introduced to my current tuner (Torqued Performance) and have loved every minute. It's everything I expected a VF52 to be. LOL

My current Forester, being a 4EAT, I didn't mess around and went straight to VF52 hahahaha

nate_fisher

To get better spool you need to ditch that stock intake for a aem and get a decent catback since that stocker is chocking you up. I would get 23 psi by 3400 -3600 on my vf52 and that was aggressive timing on e85 so that helps alot. I have the perrin inlet but did not on my vf52 i only have run it on my 20g but i will tell you its not worth replacing unless yours is torn like mine was or you have the intake mani off. I also hear a good set of headers with uppipe will get you decent spool as well but i dont know first hand. Like some one said above the best way to get quicker spool is with the tune of the wastegate duty and turbo dynamics will help out alot. I will be honest your spool looks about rite for what you have but it can be better but not by all that much.

northman

This

I added an AEM CAI to my VF setup and the response was much improved. Much better results than a catback exhaust. You must be tuned for it, though, despite what some people claim.

OrangeDot3083

I’m surprised someone hasn’t said these two things yet.

One, having the headers, cross pipe, up pipe and turbo all PnP’d will help with getting a quicker spool. It will smooth out the rough surfaces allowing greater airflow with less effort.

Two, having everything from the headers to the exhaust tips ceramic coated. Gas moves faster the hotter it is. With everything coated it will allow very little heat to be lost through your entire exhaust system keeping the gasses moving as fast as possible. The other benefit to this is cooler temps under the hood resulting in better TMIC performance.

MikeDrives1

Aggressive tuning of the AVCS system would get some slightly quicker spooling, but nothing too drastic. DO the XT's have an AVCS system?

Also, maybe some more aggressive wastegate duty cycle numbers, and a higher turbo dynamics correction factor in order to avoid terrible boost spikes/creeps.


Just some thoughts from a Tuning padawan.

__________________
- 2001FSTi: Currently rebuilding....
- 1996 Civic LX. The daily gas sipper.

Patrick P931

Many bolt-ons cost tons of money and they will give little result - at least per invested $.

The quickest way to "spool" is imho by mapping the dbw. I tested a dbw that gave me boost once I put my foot near the acc pedal. ;)

I didn't really like that, wheelspin at every stopsign...

Another way to feel the spool is to raise boost. ;)

Why settle at 16 psi when you can boost more than 20. On 95 RON. It'll give you massive amounts of torque so you forget about spooling 200 rpm here or there. ;) Go 98 RON and you can have 20 psi + a couple more degrees ignition advance and then you'll really smile. :D

So, the question is: what is your tuning method and who is your tuner. Go pay them a visit and say you want to mess with the dbw tables (all 3 of them). ;)

:)
Patrick

__________________
07 FXT
400+ ?

Superacerc

Hey mike, the xts do have avcs. I was thinking the same thing. We tuned my avcs to be aggressive which lets more air through at lower rpm. Definitely helps.

__________________
e85 on a TD05-20g, suspension and brake upgrades.