GPF

Just been reading the K27/6 thread, and thought I'd ask the same about the to4b.

I have been through the search facillity, wow there's alot of stuff in there , but no real answers....

I have a t04b, 46mm with 6cm kkk hotside and was wondering how this compares to the K27/6 - specifically in it's ability to hold boost at high revs.

I find that my boost can drop off to about 14psi by 6,000rpm. Thats with a LR DPW (tried both MBC & EBC) and std non cat exhaust. Does this sound right, and should I have gone k27/6 instead? I hope not...

Would a stronder WG spring help at all?

TIA

Regards

Graham

'88 Turbo S

Evan70

Something doesn't sound right there. I'm completely stock other than a LR DPW, an EBC, no cat and Vitesse chips, and my stock turbo will hold boost all the way to redline in 4th and 5th. In 1st, 2nd and 3rd, there is minor dropoff, but only about 1psi max by redline. I think the biggest part of this is the EBC I have (Blitz SBC-iD), as in the upper gears it has time to adjust the boost level to keep it at whatever max I set (currently running at 16psi). I know it's not what your asking about, but hopefully it might help some.

cpt_koolbeenz

<<<I have a t04b, 46mm with 6cm kkk hotside>>>

The #6 hotside is most likely the problem... Change that to a #8 stage 3 and you will most likely see a huge improvemnet.

eclou

It still should not drop off to 14#. Make sure your BC is hooked up to the WG ports correctly

Kool

So what exactly are the specs for the SFR stage 1 turbo?

cpt_koolbeenz

<<<It still should not drop off to 14#. Make sure your BC is hooked up to the WG ports correctly>>>
What if he is only running 15 PSI to begin with?

Graham-
What pressure are you running?

will951

I run 16-17lbs and probaby drop to 14lbs at high revs. The #6 hotside runs out of steam up high.....

How much sooner does the #6 spool vs the #8 anyway?? People talk about how much more streetable the #6 is....

GPF

Hi Kool,

That's what I have : t04b, 46mm compressor, #6 kkk hotside - although I believe they may vary the spec slightly to suit the car sometimes.

I was led to believe that mine would have the kkk #6 machined out a little to take a slightly larger/different turbine, but I don't know if that was done or not.

Regards

Graham

'88 Turbo S

GPF

Thanks for the replies guys.

I have only just changed to EBC (Profec B spec2) and have not finished dialing it in yet (it still oscillates a bit) but at present 16-17psi usually drops to about 14 by 6krpm. I had thought that was mainly the MBC, but I'm not at all sure now.

Running 18-19psi still drops to about 15-16 like it did with the MBC.

The EBC is hooked up OK and I'm running the LR DPW in single port mode - without dual solenoids I can't see the point in dual port mode, although I do wonder if the spring is a problem ; in single port mode with no boost control ( ie full signal to the top chamber) the base boost is ~10psi and I have already shimmed the DPW.

I have other things to look at - I'm not happy with the AFM Link kit I'm using yet, and I'm starting to think that I may have some ignition problems as I get some hesitations under boost - but I just wanted to know if this turbo SHOULD be able to hold 18-19psi to the redline.

Hence the question, how good is the t04b 46mm #6?

Regards

Graham

'88 Turbo S

jimbo1111

Your turbo should be able to hold over 20psi to redline. The 46 is a very good trim. Good street turbo for a low lag setup. If the turbo is in new or good used condition than your problem most likely is not the turbo.

Kool

If you are running the WG in singleport mode. Is it not possible that the pressure is just overwhelming the WG spring?

Evan70

Ok, if you're running single port, then ignore my comment completely. I'm running dual port, which is probably one of the reasons my stock turbo spools so quick and holds boost so well. That was probably the main reason I went with the Blitz EBC was that it didn't need anything additional to work either single or dual port.

GPF

Thanks for the reply Evan70, but single or dual port aside, I just wanted to know if the TURBO was up to running 18psi to the redline given the correct control. If it isn't I'll just give up now , but I presume from your first post it should be! Or was Chris right and I would need a #8?????

Any more opinions? Someone else out there must be running one of these?

Thanks in advance.....

Mark,

"If you are running the WG in singleport mode. Is it not possible that the pressure is just overwhelming the WG spring?"

I wouldn't have thought that the exhaust pressure alone acting on the back of the valve would do this at that level of boost, but I really don't know - hence the question above!

Regards

Graham

'88 Turbo S

Kool

If I am not mistaken the stock WG can be overwhelmed by boost pressures relatively easily.

GPF

Hi Mark,

Yes that's quite right, but this is a shimmed Lindsey Racing DPW?

Regards

Graham ,88 Turbo S