DreXeL

Is it OK to run a TD05/06 -20g with no dumpvalve? I took my forge VTA off and blanked the hose, I'm now getting less lag in between gearchanges and smoother throttle response.

I know VF series turbos dont like it but will the TD05/06 -20g be OK?

Also on lift off I don't get wastegate chatter like I was expecting, I get a wheezing sound from the induction kit, is that normal?

john banks

16G might be OK, but the 20G has quite a big compressor wheel on the end of that shaft... I would use it with a dump valve unless you don't mind rebuilding the turbo or have a FMIC to try filter bits of compressor wheel if the worst happens

It is not funny picking compressor blade out of silicon hoses either

DreXeL

I do have a FMIC but I don't think I'll risk it.

Bob Rawle

Check with Andy (assuming he supplied it?), if its ok with him then should be ok however there is risk so better not if in doubt.

bob

stevebt

iTrader: (8)

i ran mine without a dump valve for about a month with no problems, but i wanted to fit a dump valve

Andy.F

(makes a note on Bens guarantee )

It does vary from car to car, as you retain the OE induction pipe and are not running really high boost, then I would say that if you are NOT getting a choo..choo..choo... sound on lift off AND no part throttle jerks, then there is no problem. If you are experiencing either of the above then you will shorten the life of the turbo bearings and may damage your maf sensor.

An uprated recirc DV such as the Forge is a good midway solution to improve pick up whilst keeping the compressor flowing adequately.

Andy

dowser

Been running mine blanked off at up to 1.6 bar for 3 months and ~2k miles so far, no problems except "MAF Lurch" (pat. pending ) when going from boost to half throttle. You quickly learn to drive around it.

Richard

DreXeL

I do get the choo choo choo sound when lifting at low revs, but as you know Andy I'm not making much boost at low revs anyway. I'm getting no part throttle jerks.

Pavlo

I would always use a dump valve with a larger turbo and MAF sensor. However, for drag racing I put a much stronger spring in my forge unit, which maintains much high pressure levels in intake pipes during lift off.

For everyday driving the MAF lurching was the most annoying part, for instance when going from just a few psi boost to vacuum.

Even on a MAP only ECU I would run something to take the edge of the transitions and give the turbo an easier time.

TD05 is much less of a problem, and never had any real problems with no DV on the various cars I have mapped that haven't had one. Also as ANdy points out, the factory inlet pipe is very good at avoiding these nasty conditions.

Paul

David_Wallis

Paul / Andy would you consider using a dumpvalve on my config??

Pavlo

I might do for day to day driving just to make it a little more inconspicuous(sp), but I wouldn't bother for track/drag. I will find out for myself soon!

Paul

David_Wallis

Let me know how you get on.. as its obviously a little bit of hassle..

David

Pavlo

I wouldn't bend over backwards to fit one on a car without MAF sensor that uses a robust turbo.

Paul

AndrewC

Interesting, I've been running a f/e TD05 without a dump valve at 1.4bar for about 18months. Over that time I have added a FMIC and free flowing inlet pipe, both have had an effect on 'choo choo' factor but this is just noise for me as I use a Link ECU so no MAF. Every time I have the downpipe off (seem to be quite frequent at the moment) I check the turbine shaft for play and it's still as smooth and play free as when it was first installed. I recently ran a VTA DV for a while and this didn't really make any difference although I shimmed it to only open above about 8-10psi.

I am hoping to fit an 18G comp wheel this winter so am interested to know how this would cope as it's the same exducer size as the 20G.

Andrew...

SecretAgentMan

I ran my old 16g @ 1.5 bar without a BOV for a year or so, and had a bearing failure - the compressor was quite worn - and might have something to do with it, but after rebuilding it I didn't take any chances and fitted a large TurboXS bugger with a stiff spring, the airfilter was replaced as well.

Response didn't change much, and I don't get the chugga-chugga noises.

/J

Andy.F

David

As Paul mentioned it may improve driveability but for drag use it may introduce a bit of lag. On your set up with a BIG turbo I'd be wary of ballooning your intercooler when snapping the throttle shut at very high boost, thats the only reason I fitted a DV. It may however only be an issue with my particular set up where there is a very small volume in the tmic.

Andy

Pavlo

Never thought of that Andy, good point.

Well tuned dump valve that just bleeds off excess over say 1.5 bar on liftoff shouldn't introduce much more lag. And I never lift when drag racing anyway so I barely notice it!

Paul