Raceboy

Nick, it's mostly depends on COP's that are used. The best ones are passive type, not active and they give better output. Using COP's means full sequential capability and thus individual cylinder trim of spark.
The best gain per cost is achieved with coil-pack, but I personally had done several COP installs due to the fact that I get rid of the spark plug wires (and the set for coil-pack usually cost same as coil-pack itself).

nick_968

When I costed out the MSD plus coil on plug units it came out more expensive for me so I stuck to the easy route. I can see the attraction though, good luck with your setup. Looks like a nice breaker too, I may need some parts from that car if you are interested to sell anything.

Happy New Year Marcus

SoloRacer

Markus,

I just found these pictures of a 951 with the turbo mounted where I believe you want to put it. I completely forgot that I had these shots. Enjoy!

RolexNJ

Solo: Good find for Markus to help him with the turbo set-up. I'm sure you know that car was engineered orginally by Norwood, right? Anyway, the pics should help him. But what a nightnmare that car was, ouch. Back to the program though...

SoloRacer

Rolex: Do you know what specifically the problem was with this car? Obviously the E-Bay auction and Excellence article didn't mention anything.

RolexNJ

I don't want to go OT, but, I do know a lot about that car, some of it's history, and the builder very, very well. And of course neither source is going to mention any issues with the car, that would affect is ability to sell!

Back to the program for Markus....

SoloRacer

Were some of the problems due to the placement of the turbo? That part would be relevant to this thread since Markus is considering going that route.

RolexNJ

No...

Markus951

Thanks for those pics.. I have seen them before but have forgotten about this car. I would do it a little bit different.. specially the wastegate location and dowpipe.. I assume the problems with the car where related to the power it had... If I remember it was 2.6 liter 16 valve with 600+hp.. Id love to see more closer pics of that turbo setup..

I have not done any measurements but this kind of setup for exhaust manifold should decrease turbo lag quite a bit and throttle responce should be improved as well.

Other problem here is the temperature...IMO our cars seems to work better with hot exhaust manifold.. I took my car to dragrace couple of times during last summer and exhaust manifold allways cooled down in the lineup.. Before the strip I allway's had to do the burnout and get the EGT up to 700 degrees C.. Below that car was guite slow to get on the boost.. with 1st gear.. with 2nd and 3rd it worked quite ok because EGT was up allready.

I did wrap the whole piping to termotec that helped a little bit but I am sure the gains are bigger with exhaust manny like this..

We all what the Stock 951 piping from exhaust ports to turbo look like. In most turbocars turbo usually sits in the place where exhaust manifold is attached to crossover pipe.. but not on our cars.. on our cars there is still long way to travel form exhaust manifold through the crossover piping up to the turbo..so every time you want the turbo to spin you have to fill the whole piping with the exhaust gasses..and then you see something happening in boost gauge.. and as mentioned before while not doing WOT, the whole exhaust will cool down by creating effect like there is something on the way on the exhaust gasses to travel out.


Its ok form most of our cars, but its getting crucial when you wanna go up by making more power and choosing a bigger turbo.. I think specially then our stock exhaust system is not up to its job.. and specially on streetcars where you want to have nice responcive engine with broad powerand.. In racecars when you are going WOT most of the time its not that crucial.

This is BMW bike header but I think in design wise my future one will look quite similar, now if you compare the distance from turbo to exhaust ports to our stock system difference in piping lenght is quite remarkable..




Markus

Markus951

Little update..

Seems that my wreck will be a little late and I have to hurry up with my build-up. In time wise I might revise my turbo relocation project - everything depends when I can get that 968...

I have spoken lately with couple of guys who have had great time to share their experiences how my engine should be built etc..
And I finally got in touch with Zoran from australia whos 968 turbo was in autospeed mag. who has driven hes car with turbocharging 165 000 km and from that it has seen 15 000 km track days. No failures

http://autospeed.drive.com.au/cms/A_1327/article.html

Apart from that this is how I think mine should build

Bosch 044 fuel pump
10mm fuel lines.
Stock fuel rail.
990cc Precision turbo injectors
Aeromotive billet fuel pressure regulator + fuel prssure gauge..

Pauter con.rods
Wiseco 4032 pistons wiht PC9 skirt coating and thermal barrier dome coating.
Compress ratio 9.5:1 (what clearences are reccommended?)

Pauter + wiseco combo weight nearly 250g less then stock. So I will save totally 1 kg of rotating mass...
Porsche OEM rod bearings (coated)
Crank + clutch assembly + crank pulley balanced dynamically

14,5mm head studs torqued to 150nm possibly from heritage, but I could also have them custom made.
Cometic Phuzion head gasket with gas-filled o-rings.
SS exahust valves
Stock 968 cams with variocam connected
Stiffer valve springs.
Mild port job on the head

Oil pan baffle from Lindsey
Crank Scraper from crankscrapers.com
Modify stock oil pump for more oil pressure..
Relocated Oil filter for easier use
Mocal 25 row oil cooler.

Stock flywheel with GT2 aluminium pressure plate with 968 clutch disk

GT35R with 0,82 AR
9" AEM air filter with 4" induction piping.
2.5" SS intercooler piping
300*600*100mm custom front mounted intercooler
Tial 50mm BOV

Porsche Cayenne Turbo Coil In Plug ignition system with Full sequential mode

Custom intake manifold with 50mm full radius trumpets and 67mm throttle body and 150mm runners and mirror polished plenum (size 5.5Liters)

3" catback exhaust with 3" downpipe
Tial 40mm wastegate dumped to atmosphere via separate exhaust piping.
Ceramic coated turbine housing, exhaust manifold. Downpipe wrapped to termotec

EGT sensor
AEM wideband lamda.

According to Zoran I have to upgrade my engines breathing system, have any of you upgraded it here?

Also have any of you installed 968 steering system into 951. Is there any difference?

All comments are wellcome

thingo

Doesn't Zoran's use the 968 intake, wouldn't that be a big restriction on the inlet side? You don't feel the stock headers will be a limitaion.
Just my thoughts.
I'm going to use the same turbo with my 968 project, 8.5:1,Wossner pistons Arrows rods.Motec

Duke

Markus the spec looks awesome!
IMHO you should revise the turbo location project. I don't think the gains will be worth the extra hassle. Plus, when keeping the turbo in its original place you have a better chance to do a proper header design.
With thermal coating and that turbo you will not be dissapointed in spool-up

pete95zhn

Isn't that plenum a bit large for 3l engine, IIRC recommended size is ~70% of engine's volume?

How about runners, 150mm sounds rather short...it's ~250mm with intake ports...with 50mm long trumpets 300mm altogether. Sounds like high-rev peak tq.

Duke

Usual recommendation is 1.5 times the displacement for plenum size.
150 mm runners sounds good to me, that will give very nice top end breathing with a flat tq curve.
Personally I want an engine that has a flat tq curve to redline. I don't like the truck style power curves!

Markus951

Stock headers are build for torque not for high rpm.. I think they would do just fine in the beginning. Also 16 valve heads are poor what comes to make torque in lower rpm. I will try them out firs with 951 crossover piping..

In 951 8 valve engines speedforceracing headers can make from 30-50 hp difference in same boost level, but you will loose some torque on lower rpm.

I think the stock header is worht to try out. If they become limiting factor. I will replace.

Markus