964RS mit MoTeC - Page 2 - Porsche General - PistonHeads UK

I'm with you, Colin. But where's Geoff at AmD for that counterview? I have got the exhaust and filter sorted, so if you could just sneak it past the VAT man it'll be into bargain territory

Questions: If I go for a 3.8 conversion, will Motec get it up to 350bhp? Would you recommend the 3.8 big bore conversion? Do you have to do cams at same time as the 3.8 conversion, and will it help?

...and can you replace my CIS with it in my T2?

The bottom line is that, as a Professional Engineer I never slag off another company or product because unless you have exhaustively tested every one you will never really know what works and why. So all I can comment on personally is info based on my own experience. BUT, what I have learned is that the standard fuel injectors run out of flow (at standard regulator pressure) to get more than 300bhp ish out of the RS engine, so once the stock motronic ecu is programmed to open the injectors continuously what you get is all you can get, period. No more fuel = no more power irrespective on the quantity of air going in. With Motec the important part of the equation is to fit bigger injectors then control them sequentially for the entire range. More fuel + same air = more power. More fuel + more air = even more power. What I would like to point out though is that if anyone wants to talk business then please contact me directly, I'm not on the site to advertise, only to (hopefully) inform those interested in the thread. Regarding the VAT Dom, just prove that you live in Jersey and drive your car at no more than 40mph, then I'm your man!

UV, Motec can be fitted to any engine if you are determmined enough, but the quality of installation and mapping is critical to success. On a 965 I guess that the installation would cost around £2-3000 more than on a 964 as the manifolds and entire injection system has to be replaced. We have Motec on a 964 engine that we have converted to turbo, and it is giving over 500bhp at 0.9 bar and 25mpg on a run. That's the real beauty of electronics. Dom, The right cams are probably more important than capacity so that you cam maximise the performance of the intake system. We have achieved 360bhp from a "little" 3.6 that had just cams, head and case porting BUT it also had individual throttle bodies and equal length headers. The 3.8 usually just makes more torque with the stock cams as the bigger capacity is flow limited by the valve lift curve, but I reckon that we could get a proportional increase from a properly built 3.8 if the heads and cams were done right. Interestingly the 993RS only just makes the same power as the 964 when fitted with Motec, but it is 10Nm short in the torque department. Work that one out.

Colin, Welcome on board! So thats Domster's and my RS interested in Motec next spring. I can feel a 'all for one, one for all' or 'I'll go for it, if you do' moment. All I need to do now is save 1K a month for the next 4 months and hopefully 320 bhp here we come!

Colin I don't think anyone who actually knows their Porkers will despute 320bhp from the 964 with motec. It is after all only 40bhp more than I have seen on de-catted & chipped/re-mapped cars, and around 20bhp more than hotfilm equiped cars and they retain std engine mgt & injectors. I know you are not a fan of hotfilm and after driving several I've not been able to drastically feel the difference over just a chipped car. Infact sometimes hotfilm cars have felt slower on the road over just chipped & de-catted cars. However after seeing the bhp on another companies rolling road I know it can give the power but only if it is set up properly and the engine is in good condition, ie good compressions & cyl leakage). I know to all these city boys £4k is merely the bill from a client lunch, but to me £4k (plus exhausts?) is a lot of cash for a few more horses when £1500ish can give you a mere 20/25bhp less. I would certainly like to drive a couple of RS's back to back to compare. I know you have lots of interesting cars up in the frozen north, so I definatly think a visit is in order in the future. Hmmm I cant seem to find Warrington in my London A-Z do I have to take the Waterloo line.....

Colin I'd have been there ready for next year's track day season... except I just bought a new house. So no available dosh. I'm sure it won't be long before Graham T (tron) plumps for it, though. P

Would my 930 Turbo benifit from this upgrade in the same way as UV's? Steve

The 930 is an interesting one. If you are interested in power, then conventional tuning will give 400bhp quite easily (such is the overfuel of the K-Jet system), so if this is your goal then forget Motec as it is unnecessary. However, although we have squeezed 461 from a stock 930 engine with cams & lots of add ons, at any power level of more than 450bhp Motec will blow the doors off K-jet and will be ideal right up to the engines 700bhp ish limit. BUT If you are totally hacked off with 15-18mpg and would like to see 25-30 cruising, and you want 400bhp, and you have or will fit the usual headers/intercooler/turbo/silencer package, and you can afford Motec, it is definitely an inspired choice, you cannot fail. Funnily enough I desperately want to fit a Motec system to a 930 if only to give the old girl a new lease of life and see what it will give, but my own desires will have wait for a a paying job as my 125bhp/litre 3.6 n.a. development is bleeding me dry at the moment.

Colin, Howcome no one develops reliable, affordable and significant performance upgrades for a normally aspirated 996? Do you have anything in the pipeline or know of the options available?

Jason, The bottom line is that IMHO the 996 engine is not a very good design, so if you are serious about performance and want a 996 you buy a GT3, the engine of which, of course, is based on the 964 bottom end. There are the usual dme, headers, cats, cam packages that will add around 20-30bhp, but really the engine is not the best to start with so although Gemballa, TTP and others turbocharge the beastie, there is not sufficient demand for high end products as the GT3 starting point makes far more sense. Saying that TPC are developing a charge cooled supercarger package for the 996 which should be ready soon, so watch this space so to speak.

Colin, Thanks for that depressing clarification! Have you come across/opinions on the ROOCK upgrades for the 996. I am again thinking about their sports exhaust, incl new headers, 100-cell cat, rechip etc. This produces an extra 30bhp, I am told. Costs about £3k. Alternatively, I may just get the Porsche Sports Exhaust fitted - no performance upgrade, but SOUNDS more powerful! About £1,200. Any words of advice greatly appreciated. >> Edited by JasonS8 on Sunday 13th October 14:42

Jason, I cannot comment on the Rooke package, but I suspect that they offer similar a conversion to Cargraphic, Techart, Gemballa, RS, and everyone else. If you want me to quote anything please mail me offline, I'm not here to do business, believe it or not I actually enjoy passing on my Porsche experiences.

OK, I have been thinking (v dangerous I know )... If hot film etc cannot go above 300bhp because of injector limitations, and Motec can produce 320bhp with bigger injectors, what about if: ...you put uprated injectors on a 964RS without Motec, and just remapped the existing system (with or without hotfilm). Would you still get 300-310bhp, just for the cost of some injectors and a chip remap? I'm sure Motec is fantastically clever, but is most of the work being done by the injectors, and a mere bit of fine tuning being done by the M48? Cheers Dom

There seem to be a lot of MAP sensor kits springing up in US 951 land using a Link Microsystems box to do the fuel map adjustments. Are these a viable alternative, as they are cheaper than the MAF kits?

Dom, Please stop thinking immediately, you are clearly demonstrating that you have far too much time on your hands and could be jeopardising your status. Look, if it was as easy as this don't you think me and Adrian would have saved ourselves a fortune in time and money? In a nutshell you have to run low impedence, high flow injectors if you are to get the best out of a system like this as there are very few high quality, high flow, high impedence injectors available (and the ones that are available are very expensive). Anyway: std 964 injector 16 ohms, Motronic current 0.75A peak; our replacement injector 4 ohms, Motec current 3A peak. Fit our big injectors onto Motronic, result = blown injector drivers. Use other big injectors with high impedence on either remapped Motronic or with piggyback, result = poor resolution = unhappy customer. As for MAP systems, the theory is great and I actually prefer the concept, but the bottom line me is that: 1. Motec works every time (for me anyway!) 2. I cannot afford to reinvent the wheel 3. I cannot afford to have unhappy customers You have to realise that there is only so much that any one person/business can do and be good at it. Jeff @ AMD and others do chips and Mass flows, I do Motec, the customer makes his choice and either comes to me for what I do best or goes elsewhere because he cannot afford it. Understand thet I would dearly love to have ALL the answers, but this old brain can only take so much and financially I have run out of reasons for looking at alternatives just because I am interested. The bottom line is that is anyone is prepared to pay for my entire learning curve, I'll build them a MAP system and find some compromise injectors and find your 320bhp without fitting Motec. BUT, what happens when they come back for cams/exhaust/throttle bodies and we find that the system is not good enough and we have to fit Motec after all?

Cheers, Colin. Interesting stuff. I was sure there'd be some reason like impedance/ohms etc but all them injectors look the same to me, although they can sometimes come in some very pretty colours I have more or less decided to keep the car pretty much standard, apart from a half cage, and concentrate on modding the engine, rather than going mad with carbon fibre doors, low drag mirrors, front and rear spoilers etc. Funny thing is, that electric rear spoiler just seems a *tad* noncey on such an uncompromised machine, so I was toying with a fixed one that weighed less. Don't need the extra power over the winter anyway, as it is hard enough to put 275-280 down, so plenty of time for me to save up for Motec etc.

Dom -if u are looing to change yr 'nancy' wing, let me know -I'm looking for an original fo the Cup Car -at the moment running a Techart wing with too much rear downforce approaching 150....

Hi Melv I have been talked out of this, by a few cognascenti, simply because: 1) originality rules apparently! 2) the weight of the motor isn't that much 3) keeping the pure lines preserves Q-car subtlety 4) I'd have to do front splitter to balance the extra downforce, and that would be a bitch for speed humps 5) in a sad way, I quite like the nancy wing going up and down like something out of Knightrider Cheers for the thought, though. All the best Dom

Yes on all points. I have a big rear wing and front splitters and: 1. I osciallate between liking the agressive new look and preferring the original lines. 2. It's a heavier rear wing 3. The front splitter is already cracked due to a bastard speed hump 4. I miss the moving wing, too.

OK folks, Colin's putting his head above the wall for the snipers. Take one standard engine, fit Motec. The result: 320+bhp @ 6100, 400Nm @ 5130; best power at flywheel (to date) 324, best power at the wheels (to date) 288; fuel consumption reduced, engine idles rock steady. Downside: £4000 fitted. Upside: it works everytime. Problem: No body believes that it works. Solution: I will fit it and if it does not make more power than any system already fitted I'll take it off and put whatever back on, all for free. Come on guys, what more do you need to know?