Category: Technical

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Liquid Cooled M96 IMS engine retrofit part 2

MORE 996/997/CAYMAN/BOXSTER ENGINE STUFF

Feed back on the liquid cooled late-model Porsche engines has been mostly inquiries and requests for preventative measures. To repeat, more frequent oil changes, especially for low mile, seasonal use cars seems to be the best prevention. With early detection, by way of listening for whirring, a grinding noise that was never there before and/or, an oil leak in the area of the clutch bell-housing and rear main seal area being the next best.

The photos accompanying this follow up article show parts from a 2004, 996 with 24,000 miles, never tracked, one owner, six year old car. Without warning the intermediate shaft bearing seized and broke the support shaft. As mentioned in the first article, Porsche recognized the inherent weakness in the rear bearing of the intermediate shaft. In mid 2005, der factory issued a bulletin that the support plate and bearing had been updated, and that any engine that may be apart for other [...]

Liquid Cooled M96 IMS engine retrofit

MORE INFORMATION ON LIQUID COOLED PORSCHE ENGINES: A TECH INSIGHT

m96-1Bodymotion has become the “go to place” for liquid cooled 911 engines. Our building of race engines from Boxster/Cayman,996/997 to GT3 Cup engines has given us considerable experience with the term “been there, seen that” Our telephone, web site and e-mail are busy assisting customers from all over the USA and foreign countries. Questions range from those regarding basic stock street Porsches to Club and full pro race cars. They span the gamut from Porsche cars in-warranty through high mileage daily driven street cars. One of the common ailments frequently discussed is the leaking RMS or rear main seal. These leaks have caused quite the stir, especially when performing pre-purchase inspections. We have heard “I have replaced that seal more than once!” from frustrated customers time and time again. The newer replacement seals and the very expensive [...]

A few observations on limited slip differentials

DSC03369The Porsche 996/997 GT3 street car is a marvelous product for street driving enthusiasts who also enjoy weekend track events and or occasional club races. A great chassis coupled with plenty of power makes for a great driving experience.   However, all of that horsepower doesn’t matter if you can’t get the power down. The power from these cars when accelerating off corners causes the inside, or unloaded tire to loose traction; this slows the rate of acceleration, causes unwanted corner exit oversteer, and kills the rear tires. The problem only got worse when the newer 997 GT3 was made available. An even stiffer chassis platform and more power put more demand on the already limited-limited slip.

In the past, we used torsen or torque-sensing differentials, made by various manufacturers, Gleason [...]

996/997 GT3 Limited Slip Differentials part 2

A little more technical analysis of GT3 diffs

If you’ve come this far, maybe you’re interested enough to go a little deeper into the differential operation and benefits of our GT3 upgrade. There are small technical differences between the 996 and 997 based GT3 street car differentials. Porsche apparently noticed the poor performance of their factory limited slip differential with the 996. From what we have heard, the warranty claim rate on the 996 differentials was fairly high. This to replace the friction discs inside, presumably to restore the designed amount of limit to the slip. Every instance ended with the same results; almost zero break away torque static, very limited ramp angle force applied with power on, and just about zero lock on deceleration. The 997 has a slight improvement in acceleration ramp angle (more on that later), but suffers the same fate when multiple track days are run, a differential with almost the same feel as an “open” diff. I think the Porsche engineers reckon [...]

1989 – 1994 3.6 liter C-2, C-4 engines are plentiful on the used market. Be careful of 1989-1992 engines, they were updated as a warranty. Cylinders were changed and heads were machined. All this because of head surface sealing problems (head gasket). If updated properly the engines are OK. If not, look out!!! Your looking at a large expense to do the update. You can tell if it has been done by looking at the cylinder head surface. This can be done while the engine is assembled. You can see the fresh radial machine marks on the bottom of the last fin. To make sure you have an acceptable engine, check for complete wire harness, motronic relay and E.C.U. These are a must and contribute to the ease and relative low cost of this swap.

Installation varies according to the year of the chassis and transmission combination. 3.6 liter 993 engines are also a great [...]

Porsche 993’s “Achilles heel” THE S.A.I. SYSTEM

& how it relates to the "CHECK ENGINE" warning light
FIRST SOME HARD FACTS:

S.A.I. is an acronym for ” secondary air injection”

This air injection system is part of the vehicles emission control compliance. It does not negatively effect the vehicles performance when correctly operating. This system does significantly lower harmful tail pipe emissions.Any vehicle manufactured with such a system, driven in the U.S. must have the system fully operational within designed limits or it will cause said vehicle to exceed maximum allowable emissions. When certain situations arise to cause an actual failure, or, conditions exist that the vehicles on board computer diagnostics predict such an occurrence is likely to cause elevated levels of emissions, it will set a fault code in the ECU (electronic control unit) and turn on the “check engine” light. Any vehicle with a check engine light on will not pass state mandated annual inspections.

MOST FREQUENTLY ASKED QUESTIONS:

Q: How do I know what is the cause of my [...]

G50 transmission with solid mounts ready for installation

g50transmissionInstallation of late style five and six speed gear boxes can be an economical way to increase value and performance, as is converting four speed 911 turbos to five speeds also utilizing the g-50 series boxes.

Choosing the correct box is first: g-50’s are available with both open and limited slip differentials. The later being more desirable for track and serious street drivers. Of course, the limited slip boxes cost a little more,usually $600-1000. The best choice for the track is still the quaiffe or torsen differential. We can provide this upgrade for an additional $2500. If you plan on this option buy the open differential and save afew bucks.

Ther are several ways to install these boxes into 1972-1986 chassis. The factory installed g-50’s in 1987 and later cars. They redesigned the rear torsion bar tube to allow [...]

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