New Janspeed Exhaust Update

[Guest]

Hi Guys, Thought I'd say hello and thanks to all of you who gave me advice on exhaust's - I ended up opting for the Full Janspeed system, although the middle/de-cat section was for the earlier car I was assured this could be made to fit by cutting the new and old sections about but my mechanic advised me that this was probably a bad idea as if the section broke I may be forced to buy both the original porsche section and the Janspeed section just to get a centre pipe again and this could be EXTREMELY expensive so I contacted Simon At ESS (The Nice chap who supplied it - Cheers Mate!) and we arranged for me to take the car to Janspeed by Stonehenge and leave it with them to make a new section for the late model cars.
With both sections fitted I am amazed at how much better ther car is now its lost pretty much all of its 80's supercar mega-lag (which was good fun in the dry but less so in the wet). and the exhaust note is really good (especially as being a four cylinder engine I was a little concerned I may end up with something that sounded like an XR3i) and I can now hear the turbo spooling up - which I love.
This also means I now have a reasonably good condition standard exhaust middle section available if any-one is interested.
Of course now I can see and feel that the car is getting better boost lower down but that it's bleeding off at the higher end and I'm thinking that a dual port waste gate is needed what do do you think?.

 

[Fen]

I think a proper wastegate is a good next step because even a good standard one is a poor design and if it leaks then nothing else will be able to compensate.

What we saw yesterday on the boost plots of cars with ugraded wastegates was that the boost still falls away. It's a pretty linear decline from the peak on the k26/6 cars and has a level peak section of about 1,000 rpm then a drop-off on the k26/8 ones. Only the modified turbo cars could truly hold boost at high revs suggesting that the k26 gets breathless. That said you need a good wastegate to make use of a bigger turbo.

I spoke for a short time with Simon yesterday and he indicated he might be interested in providing a modified exhaust to allow the direct bolt-on of a TiAL wastegate which would get around the problems the guys on here were having with adapter plates loosening off.

Finally if you get tired of the turbo spool-up sound I can vouch for the fact a MAF (and I assume MAP) kit will sort that out for you - you can't hear the turbo for the induction.

 

[Guest]

My dads 944 will need a new exhaust soon, can you advise me on the best make? Price and where to go? Any links etc?

Thx Scott

 

[sawood12]

I can testify the benefits of a dual port wastegate and the Janspeed exhaust. I've got a DPW and an ESS Janspeed back box fitted to my otherwise standard 220bhp Turbo and got 137.5 bhp with the peak boost at 0.8 bar which is standard (I set this against my in-dash guage as well!).

However the plots also showed that as soon as my turbo achieved peak boost at around 3500rpm it dropped off as the revs increased to just above 0.6 bar boost as the capacity of the turbo was reached - i.e. it ran out of puff. So with Guru chips+3bar FPR, 1 bar or so of boost and a K26/8 turbo I should be knocking on the door of 290+bhp!! Then a MAP kit then a.... It's just like the darkside of the force this modding lark - as master Yoda once said: "Once you go down that path, forever will it dominate your destiny!"

 

[sawood12]

Just a further bit of info - the plot I got that shows the air/fuel ratio showed that my standard ECU/AFM configuration was able to cope with the faster spool-up of the turbo. In fact it shows the mix slightly richening until about 5000rpm where it starts to lean off. So standard ECU and fuel delivery system doesn't appear to be an issue on a K26/6/DPW equipped car upto 0.8 bar max boost.

 

[berg944]

With both sections fitted I am amazed at how much better ther car is now its lost pretty much all of its 80's supercar mega-lag (which was good fun in the dry but less so in the wet).

How does this help please?

I am interested in this because mine gets that frisky in the wet I can only drive off boost.

Mike

 

[Guest]

In the wet it just seems to allow more 'Linear' throttle response in as much as the turbo comes in smoother with a more progresive build of boost up to where it all really gets going (if that makes sense?) in otherwords it makes less 'all or nothing'.

ORIGINAL: berg944

With both sections fitted I am amazed at how much better ther car is now its lost pretty much all of its 80's supercar mega-lag (which was good fun in the dry but less so in the wet).

How does this help please?

I am interested in this because mine gets that frisky in the wet I can only drive off boost.

Mike