Most people seem to be torn with this question, half say its safe and half dont.

I am upgrading my 03 STi on friday to a FMIC and in the process would like to go DV'less (personal choice). Half the people I speak to say the VF series turbos cant handle it whereas the other half say its fine.

What do you all think? Has anyone done this before? I am hoping to upgrade the turbo to a MDX555-500 in Decemeber, should I just wait for that?

Cheers for the help guys im not the greatest with mechanics

This will be the new turbo: http://www.carbenfibrecreations.co.u...roller=product

 

I tried this mod for a while on my 05 STi.
Yes it made an interesting noise, and the turbo seemed no worse off for having done it.
However I found no tangible benefit from it at all. In fact it made performance worse by 'stalling' the turbo between gears.
So based on my own experience I would vote no, and have done.

 

Thanks for the input

 

Ran my VF28 dump valve less for a while and then replaced the VF for a TD05 20G. Again running dv less on that with no ill effects.
The VF did have a cracked exhaust housing though when I removed it so not sure if running dump valve less had anything to do with it.
I found no difference in performance.

Id say wait until you've changed your turbo.

 

Running DV less wil put huge stress on the compressor and shaft bearings regardless of what turbo you run, on top of that as already described all the charge air is exhausting over the compressor wheel and stalls it in the process, this makes a nice noise but will significantly reduce turbo response post gear change. My personal pref is to run with a VTA DV that is setup and matched to the engine setup especially with a large front mount.

 

Performance wise im not bothered if it stalls between gears, I dont race the car and never will its purely for show purposes. That said if theres a change, which im guessing yes, that I could damage the turbo to the point of me having to replace it then I wont bother.

 

My brother did this to his scooby, and to be fair when the ecu was using the MAF the car drove horrible, you could feel the turbo stalling and I think the MAF was trying to compensate for it, and it was very jerky, and not a nice drive at all.

As soon as he went MAF-LESS with a aftermarket ecu the car drove different,much smoother!!!

 

cold air intake with fmic and recirc dumpvalve it will flutter nicely whilst still drive nice .

 

I run MDX321T mafless & DV Less, & I love it, much prefer it to my VTA set up. No performance gain as such but I find if you are quick through the gears it seems to spool better than a VTA. Both Laterall & SC still honour warranty on their turbos running DVLess. I have heard some turbos can't take it but I think most roller bearing turbos are OK.

 

You'll find nearly all people who say running dump valve less will decrease your cars performance have never tried it.
If you've got a decent turbo then go for it, you'll not notice any difference in the drive. My old classic running mafless, front mount, large kandn and a 20G drove wonderfully and sounded fantastic.

 

You only feel the real benefits when driving on track or on private roads tbh where you are changing aggressively enough to appreciate the retained boost pressure Otherwise it's hardly noticeable IMHO, nothing negative. You need it mapped to suit as there are assumptions being made by the MAF and ECU which need updating

As far as damage is concerned I am running 1.4 bar on a TD05 and it's not been an issue. I also ran the identical set up on my 555 wagon with ALS and LC. When I took the turbo off breaking the car it was mint

 

Iv changed my garret gt30 (rotated) a couple of times now due to wear caused by running no DV but it sounds awesome lol

 

Thanks for the input guys, when it comes to mechanics im a little slow so I need to make sure im not going to put my car at risk by doing this

Tomorrow I'll be fitting the FMIC and as standard I'll be putting the recirc back on till I decide what to do, once Ive made my decision I'll get it mapped again