A couple of turbo tuning questions

Its getting to the business end of the year for my car. I've put RS coolers on and have a 5bar FPR and hybrid turbos (16/16g) to put on. I may also have an IPD plenum fitted. I've currently got a 200 cel exhaust on. I'm going to get the work done by my indy and then drive thr 200 miles over to Wayne Schofield to map the car as he does all my cars. My questions: 1) Can I have the FPR put on at the same time as the turbos and then drive it 200 miles to have it mapped? Am I likely to break down? 2) Can I realistically achieve my anticipated output of 650bhp with 200 cel cats? I'm trying in vain to get a decat system or 100cels but the price is prohibitive at the moment. 3) Does anyone know the most efficient boost level for these turbos. From what I've read on the Yankee forums it is 1.3 bar? Any thought? I know I can drive the car with the new turbos on as long as I stay off the boost but the FPR concerns me. TIA :thumb:

don't know the real answers, but as far as i know anything above 1.3 bar and you will probably need a secondary fuel pump to ensure no fuel starvation to the engine. apologies but i just remember a conversation with my tuner. I also imagine you will need the IDP 78mm to do it properly. 650 BHP or even a little lower is the total limit i think you can achieve with GTRS intercoolers, again what i have been told and actually very similar to your journey, what i have but with k24 turbos, the IDP and bespoke exhaust plus remap etc..... I am running a total turn key reliable 570 BHP with sooooo much grunt in the 50 - 150 mph range and find it to be enough for the time being!!! Goodluck,

Thanks for that FRP. I've actually upgraded the stock fuel pump with a much more powerful walbro unit with that very problem in mind! Hopefully the fuel starvation issue is one I wont encounter!

I wouldn't as it will make it richer, not a problem for around the corner but 200 miles of potential bore wash won't help your cylinders. If you think about what's happening, injector will be open for the same time as previously but with much higher fuel pressure, so more comes out. Can you not just fit it when you're at your tuners. Cheers Darren.

Thanks Darren, Yeah, it looks like i'm going to go that way. Wayne is using the RR at ninemeister so I've booked the car in with them on the morning for the FPR and then with him for the tuning on afternoon. The FPR is coming from FVD and is this one: http://www.fvd.de/de/en/Porsche-0/9...11019980-5.0-BAR-Fuel-Pressure-Regulator.html Also got my 1bar wastegates coming from Vivid Racing today too! I cant wait to get this thing wound right up! I've just come back after a lovely drive in the turbo using the mid range shove and loving it - I can't wait to see what its like with another hundred or so ponies! Think I'll be keeping PSM on for a while! Its proving difficult to get anywhere regarding exhausts though. There is a standard turbo system on ebay which I could use at MOT time and have the cats cut off my milltek but nowhere seems to think they can do this to the milltek as it is a bit of a strange shape. :frustrated:

these cars have a wideband lambda so it wont make it richer (well maybe a touch if the injector duty cycle is too low and they cant cope with light throttle town stuff). It will control as near 1.0 as possible until you nail it then 0.8ish 1.2bar MAX with only a 5 bar regulator and around 600- 620bhp maybe a touch more. You need 60lb injectors (minimum, some use 72lb) and around 1.4bar to get 650-670bhp. 1.5bar and you are pretty much flatout with 16g. i thought you were going billets?

Yeah I was but I'm limited by the tip box and I got the turbos for a good price. If I max the current set up out I should be just below the point where the box would become unreliable which is probably the best place to be. Following this I'll move on to completely sorting the suspension and handling. After that I might be wanting to play with the big boys and get a £7-10k box rebuild and some bigger blowers...... Who knows!? :dont know: PS: out of interest you say 1.2bar MAX but what would happen if it were set at 1.3-1.4bar? I ask because I dont know and want to understand. Cheers!

I was going to go Billet and worry about the Tip Later lol after 1.2bar you will run out of fuel on a 5 bar pressure regualtor alone. I dont have the flow stuff to hand as I am offshore. but 1.2bar with billets and standard injectors and you will be over 80% duty on the injectors. going higher is dodgy without real close logging. You can always get your tuner to limit torque lower in the rev range (where most torque is produced) to help your box. I did that on my 535d when it was running close to 400bhp.

Great thread and happy to admit I'm learning loads opcorn:

Me too! Have you got a durametric yet? If so (and for those who have but don't do anything other than look for error codes) have a read through this link. Thanks to JD for giving me this it is SOOO useful! DURAMETRIC

Wow. Consider it on the list! I'm going to give it another 12 months I think of getting normal motoring before I start 'tinkering'. Figuring where to start. 997 front calipers would seem a good first mod. How very boring!

Paulmc is correct about fuel in this engine - he drives identical 996 3.6 Turbo This is original fuel table from 420hp model. They more or less run this all the time excluding start up, auto choke.

With a 5 bar fpr you should consider doing the fuel hoses too. At the power you want you will be running the injectors maxed, I don't think you'll be able to hit 650 with this set up. You can read up on the injectors. Check the car for boost leaks. Consider upgrading the air intake to the turbos before the plenum. I went for fearnsports intercoolers. You'll also need a new clutch.

Thanks Tim! What do you recommend for the air intakes? Car is having full boost leak test after fitting of new turbos and exhaust before going for FPR and mapping the next day. I hear what people are saying about the injectors. I don't want to run a 100% duty cycle, i'd like a little safety net. Do you think an IPD plenum would help to increase power output? I hear they are great for mid range and their gains are magnified by other concurrent mods? Is there a way to work out how when the injectors will run out of puff and at what boost for which turbocharger or is it down to the tuner on the day and the unique set of variables he is faced with?

I wouldn't bother with anything else until you put in larger injectors and fuel lines. MC