ZSA Motorsport

engine differences. 986 2.7l vs. 987 2.7l
hoping someone who knows this stuff could give me some insight....

i have a 986 2004 boxster S. race car. 2.7l motor. what are the differences between the 986 2.7l and the 987 2.7l?

i think i saw online that the 987 generates like 20hp more, afew more ftlbs of torque. im curious if thats simply due to programming of the ECU opening up the engine more and thus the 986 tuned could generate the same.

i ask because my 2.7l 986 motor i have the ECU tuned and get like 220hp at the wheels. and we're considering a 2.7l 987 motor for a 2005 race car build, and we're not sure if it will infact generate the same, post-tuning, 20hp more than the tuned 986. or again if they are basically the same motor in terms of power, and its just the 987 comes tuned a tad more from the factory.

i think there is something with the cam,lifts that supposedly helps with torque, but i know nothing in this area. figured this would be just about the best place to ask...thx in advance.

Ray S

If memory serves when the 986 2.7 was first introduced in 2000 the car had 217hp, later 986 2.7 had 228hp. When the 987 came out in 2005 the 2.7 was essentially the same but Porsche had made some improvement to raise the power level to 240hp. According to Porsche here is what they indicated was changed

The six-cylinder power unit of the Boxster remains largely unchanged with the exception of one significant modification: The bearing bridge on the crankshaft is now made completely of aluminium reducing engine weight by a significant 5.5 kg. Apart from its increase in maximum output, the 2.7-litre power unit offers more torque at low and medium engine speeds. Among other things, this is attributable to fundamental, ongoing development of the entire air flow system from the air filter to the exhaust tailpipe.


The new, even larger filter, to take just one example, significantly reduces counter-pressure and facilitates the process of drawing in air. Another new feature is the twin-chamber distributor pipe complete with a distributor flap. The optimised air supply provided in this way means a lot more thrust from just 1500 rpm, with maximum torque of 199 lb-ft between 4700 and 6000 rpm.


In 2007 Porsche added Variocam plus and output climbed again to 245hp. That engine carried through to 2009 when Porsche introduced the new DFI motor and raised displacement to 2.9l.

Hope this helps.

TIM COSTA

Maybe Im missing someting but if you have an '04 Boxster S then you should have a 3.2l motor. That is unless you changed the motor out for a smaller one for some reason.

Charlie C

That had me wondering too.

Byprodriver

When the 987 was introduced Porsche claimed more efficent exhaust & intake systems along with software tuning to take advantage of the improvements.

944J

what's the best page to list all the differences between the boxster/cayman models? not just engine but the entire car (features, brakes, interior, bumpers, etc.)

racer

while off track, it was my understanding that DFI was NOT put on the base motor (only the "S"s).. hence the displacement upgrade to 2.9l to up the power on the "entry level" cars. And annoyingly, the Cayman has a HP bump over the Boxster.

Ray S

You are correct the Boxster and Cayman 2.9's are not DFI and the Cayman has 10 extra hp

Bill Lehman

I was involved in a discussion with our region's local expert this weekend. My understanding was that the intermediate shaft bearing (which was prone to failure) was increased in size and oiling as compared to the early 986 and 996 engines.

Ray S

Bill, the current issue of "Total 911" magazine has what I believe is the most thorough analysis of the truths and fallacies about the IMS problem, its root cause, an estimate of how many cars it will affect, and the simple repair that can fix the potential problem (LN Engineering aftermarket bearing).

The article says Porsche enlarged the size of the bearing and spindle four times over the 11 year run of the engines.

Take a look at it. It really is a pretty good article.

http://www.total911.com/news/total-9...ne-is-out-now/

Charlie C

No article there. Just an ad to buy the mag...