Hi rennlisters,

After a while, I am thinking about go further in my mods. I remind you my currents mods964 3.3 turbo)

Sc cams (Option X33 )
K27 HFS (for sell)
1 bar
GSF headers
Cat bypass
LFW
Bypass waste gate
KN air filter
Forge Diverter valve


With the original turbo (K 27 7200) gave 415 hp at the flywheel.

I intend to make deeper changes, but keeping the CIS which I have the following questions:

I would like to improve the off boost mode (performance and response), but I do not know what the RC I must to go (taking into account a maximum pressure of 1 bar blowing, but if you say that is too risky could lower it to 0.7 or 0.8).

You see dangerous operation at 8.5 RC? And a 8.0 RC?

My choices would be:

1. Install only 97 mm pistons of JE Pistons RC 8.0 to 1
2. Install only 97 mm pistons of JE Pistons RC 8.5 to 1
3. Install Mahle pistons and cylinders with 3.4 RC 7.5 to 1 or 8.0 to 1.
4. Install Mahle pistons and cylinders with 3.3 RC 8.0 to 1 ( I don´t know if this option is possible)

What option for you is most advisable? Do you recomend JE pistons? I have read that JE pistons with Mahle cylinders cold make noise (due the different tolerance between materials), but that means I will have problems? They will have durability?

What is the real gains that I could expect from these changes? It is worthy? What is the total amount of horse power that I could expect?

which is the theoretical limit between CIS and RC?

Which is the theoretical limit between RC and 1 bar boost (with CIS)? And with 0.8 bar?

On the other hand, as I will do a complete review, could you say to me what pieces should change (valve springs, ect ...)

Thank you very much in advance

P.D: A picture of my car:

 

I have a set of JE 8:1 97mm pistons with ~3k miles on them. Also perfect bore 97mm cylinders with 3k miles on them, if you are interested.

 

hello zarpoxx,

I have very similar specs on my 3,3l, GSF, bypasses cat + WG (love the sound), 1bar, everything except LWFW and K27HFS. Why do you want to sell the HFS? Just curious.
If I were you I wouldnt open the engine if not really necessary (rebuild).
I will try the UTCIS-PT from UnwiredTools (Digi-WUR) to make the CIS a bit more efficient. Surely there are some more horses hiding somewhere...
Sorry no advice on the pistons, but if your engine is still running good without any leaks I wouldnt touch the internals.

Regards,

Joe

 

I'd hold off on the digi-wur for the moment, they haven't finished the development for our model. Still a few enquiries may gee them up a bit.

A question for you both, do you have 1bar springs or 1bar pressure readings?

 

Hey Steve how is it going?

I have a 0,6bar Tial Spring (large yellow one) and this results in 1 bar of boost with my headers. Unwiredtools is currently working on a updated version of the Digi WUR, I understood that it will be possible to read AFRs, they will maybe even cooperate with Dave from inyourfacegauges regarding this.

Cheers

 

Hi Joe, pm'd you.
I've got the 0.5 bar tial and get 0.98bar of boost and it holds al the way to 6500rpm. That's with a standard turbo too.

The problem with the digiwur as I understand it is it can't read our rpm signal correctly so not possible to fuly tune at the minute, athough I think they are working on it, if a little slowly.

Steve

 

Hello,

James E, maybe I could be interested in your pistons, could you send me (via pm if you prefer) the price and any pictures? Thank you.

Turboholic, I want to sell the HFS because I don´t like the power delivery (very linear). It is true that doen´t fall until red line (push like a NA motor, until 7.000 rpm), but It is a litle more laggy. I sell it in 700 euros (has only about 3.000 km). I bought it new from Imagineauto.

Also I would change it into a K27 7200 or one K27 S of similar characteristics (almost new and in mint condition).

Maybe you are correct and I would do not do anything until my engine has several leaks or something like that...

Biglicks, I have 1 bar spring and 1 bar pressure reading. I have the stock waste gate. Do you (to all) think that I should buy the tial 46mm waste gate? What would be the gains?

Regards,

Gisleno Babarro.

 

Will do.

 

the gains with changing the wastegate are mostly weight reduction, but also at the age the originals are now they are known to fail and expensive to replace. I went for the version from this site http://www.ssautochrome.com/ much cheaper, although being a copy of the tial some will say it can't possibly be good enough. Mine has been flawless.

 

Those wastegates Steve posted are not the original Tial but work perfect. If you want to be on the safe side you can still install a original Tial spring. Now that the weather got colder I have peak readings of 1,1bar but fueling is still rich enough!