s3 will slow spool. go with s2. dont know if 5858 is available with a TS housing. but one can always be done at a good turbo shop. the header would have to be made TS as well.

 

S2 or Stroker R2 will be better for my mods? Which is the best shop to make TS hotside for PTE 5858 and TS manifold? Someone else who has same or different opinion? Please let me know your opinions. All opinions are always welcome

 

In contact with two different big shops I got two different opinions.
Both of them are reputed and thank a lot both of them.

One told me that R2 cams are meant for stroker motor and Twin scroll will help a bit but probably will cost me on top end.
The other one told me that is not dealing with TS turbo systems, prefer .82 AR single scroll V Band. For cams in 2.3 recommends S3.

To be honest I am really confused. I don’t know what I have to do.
Any suggestion???

 

In this instance I feel it is close to where it needs to be for spool. The R2 can enhance power and in some cases spool. There are no twin scroll housings available for the 5858. When properly sized the twin scroll doesnt cause a loss in top end. It is all about balancing backpressure in the system and this is where combination is very important. What engine management is being used and what has been done (if anything) to the MIVEC map?

 

Hello John, thanks a lot for your time to answer.
In my case by changing Tomei with R2 how much Whp can be enhanced?
ECU is Autronic SM4 pnp Evo 9 with Knock Module (Version V1.09), to be honest I don’t know if Tuner did something to the Mivec map.
I didn’t manage yet to install (I have it) Spark Tech Evo 4-9 Street Sequential ignition with Pro 14 CDI, do you believe that could help ?
What parts do you believe I should change in order to get better spool and bit more top end or at least not loosing at top end.

 

Find out what has been done to the MIVEC map first, that will be most of the spool.

 

I get the feedback from tuner that he did something in MIVEC. To be honest I didn’t understand what he said.
Replacing cams and retune is good idea? What Whp I should expect by changing my cams with R2?

 

Based on what I have seen from switching to R2 cams from the S2s or smaller (HKS in one case) I would suspect a minimum of 25whp and as much as 50whp.

 

So is better to switch Tomei with R2? As I said car tuned with 2.2bar (=31.9psi), what about increasing boost at 2.5bar (=36.25psi), on pump gas?

 

We dont have pump fuel good enough to run that high of boost. We use ethanol to get that on the street and still have it come from a station.

 

I read that R2 cams require upgraded valve springs and titanium retainers.
As I mentioned my motor has Cosworth mivec cylinder head.
in order to go with R2 do I need also upgraded springs and retainers?