986 Forum - The Community for Porsche Boxster & Cayman Owners

986 Forum - The Community for Porsche Boxster & Cayman Owners (http://986forum.com/forums/index.php)
-   Performance and Technical Chat (http://986forum.com/forums/forumdisplay.php?f=11)
-   -   How can a 911 3.4 have so much more HP than a 3.2 Boxster S? (http://986forum.com/forums/showthread.php?t=49364)

steved0x 11-11-2013 09:57 AM

This is a very interesting discussion and I just found the other big thread by TRK on using the bigger TB and Plenum. Very interesting stuff.

Steve

Bigsmoothlee 11-11-2013 02:03 PM

Quote:

Originally Posted by BYprodriver (Post 371671)
As JR posted the head castings are the same, & all bolt bosses are there. You just have to drill & tap the holes for the intake & exhaust parts you are using.

http://986forum.com/forums/uploads01...1384189194.jpg


986 3.2 head has untapped bolt bosses to mount heat shields in 996s


Yes, I am aware of that. That's exactly what I did, but you make it seem ALOT simpler than it actually is. Being that both of my engines were out, I made a template for the 2.7 manifold and outlined the holes on the 3.4 head. I then removed the heads, and drilled the mounting bosses on a drill press since I wanted them 100% accurate and straight. I set up levels, used a lot of shims under the head, and then clamped it down to the machine to make sure the drill bit was exactly 90 deg to the hole I was tapping. Since it was a used engine, I didnt mind changing the valve seals and lapping the valves anyway.

I dont know if I'd have the nads to just take a home depot drill into my engine bay and try to drill the holes for the 996 manifold, but im sure it can be done.

Bigsmoothlee 11-11-2013 02:06 PM

Quote:

Originally Posted by JAAY (Post 371673)
Yes a 987 engine cover fits. I have one on my 3.4 conversion so I didn't have to lower the engine.

Jaay, did you have trouble with the shifter cables being too short when you installed the 3.4 manifold without lowering the engine?

Which 987 engine cover did you use? Was it from a Cayman/Boxster S?

BYprodriver 11-11-2013 02:14 PM

If you put 3.4 heads on a 2.7 you lost compression ratio & undoubtedly low rpm torque due to the bigger valves.

Jake Raby 11-11-2013 02:58 PM

Quote:

Originally Posted by BYprodriver (Post 371713)
If you put 3.4 heads on a 2.7 you lost compression ratio & undoubtedly low rpm torque due to the bigger valves.

Hmmn, what head gasket was used? With the difference in bore size at a whopping 10.5mm of bore size difference I'd expect issues. What cams were used with this?

I think he is stating that he had a 2.7 and did a 3.4 engine conversion...

BYprodriver 11-11-2013 03:13 PM

Quote:

Originally Posted by Jake Raby (Post 371722)
Hmmn, what head gasket was used? With the difference in bore size at a whopping 10.5mm of bore size difference I'd expect issues. What cams were used with this?

I think he is stating that he had a 2.7 and did a 3.4 engine conversion...

I bet you are right Jake, he did say he had 2 engines side by side in his post. Happy Veterans Day Jake & thank you for your service, both abroad & on Raby hill !

Bigsmoothlee 11-11-2013 04:27 PM

Quote:

Originally Posted by Jake Raby (Post 371722)
Hmmn, what head gasket was used? With the difference in bore size at a whopping 10.5mm of bore size difference I'd expect issues. What cams were used with this?

I think he is stating that he had a 2.7 and did a 3.4 engine conversion...

Yes, that is correct. I did a full 3.4l conversion, but drilled the mounting bosses in the 3.4 head to attach a 2.7 intake manifold to it. This allowed me to avoid lowering the drivetrain. I drive my car to work every day and the roads here in the Northern NJ/NYC area are atrocious, so lowering the engine 1.5" to accommodate the 3.4 manifold was a risky proposition. One raised manhole cover and bye bye engine!

I want to install the 3.4 manifold with a 987 raised engine cover, do all of them work or is it only the "S"model that has the raised portion for the intake manifold?

golonaus 11-11-2013 06:34 PM

Quote:

Originally Posted by JAAY (Post 371673)
Yes a 987 engine cover fits. I have one on my 3.4 conversion so I didn't have to lower the engine.

same here
987 cover got nice bump in the middle. you just need to trim off some of the carpet padding

golonaus 11-11-2013 06:40 PM

Quote:

Originally Posted by Bigsmoothlee (Post 371712)
Jaay, did you have trouble with the shifter cables being too short when you installed the 3.4 manifold without lowering the engine?

Which 987 engine cover did you use? Was it from a Cayman/Boxster S?

dont know about Jaay,but In my install yes cables are too short
just a bit tho
Simple solution is to move shifter console about 1/2"
I drilled new mounting holes and shifter boot covered it
looks and works as it should
I'm curious how Jaay solved it too, tho
btw
I'm using cover from a cayman s

JAAY 11-12-2013 05:29 AM

I ran my cables under the intake manifolds.

Bigsmoothlee 11-12-2013 06:09 AM

Quote:

Originally Posted by golonaus (Post 371750)
same here
987 cover got nice bump in the middle. you just need to trim off some of the carpet padding

Excellent, thanks.

Quote:

Originally Posted by JAAY (Post 371783)
I ran my cables under the intake manifolds.

Did you use a 987 S cover or a standard 987 cover? I see both have raised bumps, I wonder if they're different?

I didn't think it was possible to run the cables under the manifold until now... Thanks

JAAY 11-12-2013 06:27 AM

I don't know what cover I used. I think there the same though.

The Radium King 11-12-2013 06:40 AM

make sure jaay hasn't deleted his AC ...

JAAY 11-12-2013 07:03 AM

My a/c is still in. I have my top up mostly. It gets hot here.

Nine8Six 11-12-2013 11:56 AM

Quote:

Originally Posted by steved0x (Post 371263)
What all else does Porsche do differently in the 911 such that it has so much more power, and why can't we do that same stuff in the Boxster?

Steve

You can! Get 6 (six) custom ultra-light pistons machined out of titanium (e.g. the flat piston style, F1 tech, same as in the GT3), and get a tuner to design/machine you a set of cams with tad rounder/longuer intake lobes. If you have the cash, you could also get your crank re-machined and ballanced for the flat 6. Custom mapping and all, big big roars

A small and modest $20,000~$30,000 mod (350~400bhp)!

Horses are not cheap these days mate. Hence the higher price on those upper Pcars models.

Bigsmoothlee 11-12-2013 12:53 PM

Quote:

Originally Posted by Nine8Six (Post 371852)
Y

Horses are not cheap these days mate. Hence the higher price on those upper Pcars models.

I beg to differ. The power was intentionally left out of the 3.2 for marketing reasons... My 3.4 986 humiliates non-gt3 996s at autoxs

woodsman 11-12-2013 02:36 PM

Quote:

Originally Posted by Bigsmoothlee (Post 371866)
I beg to differ. The power was intentionally left out of the 3.2 for marketing reasons... My 3.4 986 humiliates non-gt3 996s at autoxs

what's that got to do with horsepower?????

Bigsmoothlee 11-13-2013 04:10 AM

Quote:

Originally Posted by woodsman (Post 371881)
what's that got to do with horsepower?????

The lack of power wasnt from a lack of funding, it was done intentionally to keep a gap between the 911 and the Boxster. Equal power ususally results in the 911 having its ass handed to it by a boxster

Jake Raby 11-13-2013 08:54 AM

Quote:

Originally Posted by Bigsmoothlee (Post 371733)
Yes, that is correct. I did a full 3.4l conversion, but drilled the mounting bosses in the 3.4 head to attach a 2.7 intake manifold to it. This allowed me to avoid lowering the drivetrain. I drive my car to work every day and the roads here in the Northern NJ/NYC area are atrocious, so lowering the engine 1.5" to accommodate the 3.4 manifold was a risky proposition. One raised manhole cover and bye bye engine!

I want to install the 3.4 manifold with a 987 raised engine cover, do all of them work or is it only the "S"model that has the raised portion for the intake manifold?

That 2.7 intake is killing the potential of that engine. The 2.7 intake is inadequate even for a 2.7 engine.

jaykay 11-18-2013 06:27 PM

Quote:

Originally Posted by JAAY (Post 371673)
Yes a 987 engine cover fits. I have one on my 3.4 conversion so I didn't have to lower the engine.

Jaay does the cayman cover mess with the soft top? Were you able to adapt ithe insulation cover to fit over it ?


All times are GMT -8. The time now is 01:45 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website