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YOUR RESEARCHWill a 3.2L mount to a 2.5L's 5 speed? - 986 Forum - The Community for Porsche Boxster & Cayman Owners
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Replace 2.5
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He replaced the 2.5 with a 3.2 using a cayman intake and a 2.7 5 speed.
Will a 3.2L mount to a 2.5L's 5 speed? - 986 Forum - The Community for Porsche Boxster & Cayman Owners
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Leading evidence: 'Replace 2.5' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace 2.5' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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I run a cable throttlebody from a 99 996, with a custom intake tube.
Will a 3.2L mount to a 2.5L's 5 speed? - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Use 10mm only
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Will a 3.2L mount to a 2.5L's 5 speed? - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Use 3.4l throttle body and a 3.4l each and immobolizer
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So since the 3.2 was only e-gas my plan is to use a 3.4L throttle body and a 3.4L each and immobolizer with a 3.2L engine.
Will a 3.2L mount to a 2.5L's 5 speed? - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Use 8mm or 10mm
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Suggestion
97-02 axles only use the small 8mm(?) while the 03/04 can use 8mm or 10mm.
Will a 3.2L mount to a 2.5L's 5 speed? - 986 Forum - The Community for Porsche Boxster & Cayman Owners
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Blew up my motor last weekend and am trying to figure out if a 3.2L will bolt up to my 2.5L. Eventually I'll upgrade to the 6 speed but I'm trying to limit my spend for now. Does anyone know it'll bolt up and handle the power?
Yes it will bolt up. not sure about being enough for the power though
A friend ran one on a autocross Boxster with a 2.9 that made about 240 to the wheels for 4 years with no issues. that car is now in California still running
Might depend on the clutch/flywheel you use -- make sure the spline count is the same
or swap the 2.5's flywheel to the 3.2.
Frankly, I'd source the 3.2L Tranny while you're in there and then sell the 2.5L Tranny.
Does your 2.5L have the center radiator? You might need that to help cool the 3.2
Mike
The bigger question is the engine controls and fuel supply returns. Those control easy swap.
Find a 996 0r 986 engine from the same era defined by same DME.
Good to hear about the transmission! Looks like I have two other hurtles 1) I have a cable throttle 2) I have an early DME that will need to be swapped. So since the 3.2 was only e-gas my plan is to use a 3.4L throttle body and a 3.4L each and immobolizer with a 3.2L engine. Does that sound like a winning combo?
Yes the 3.2 will bolt up to a 5 speed. I have a friend that quit racing spec, so he decided to turn his spec boxster into a fun DE track toy. He replaced the 2.5 with a 3.2 using a cayman intake and a 2.7 5 speed. Yes the 6 speed is beefier and better suited for the job, but the 5 speed can handle the abuse if you're not too rough with it. I personally would switch to the 2.7 5 speed only because the 2.5 is worth twice as much as a 2.7 5 speed. Even better if you can find a 987 2.7 5 speed as they're supposedly stronger and have a gear ratio close to the 2.5 5 speed. They also come with larger cv bolts.
FYI, 6 speeds go for $1000-1750 depending on condition. 986 2.7 5 speeds go for $300-700. 987 2.7 5 speeds $400-800. I'm thinking for your car and the type of racing you do that sticking with a 5 speed is your best bet.
He's using a 987 5 speed I sold him. If I remember correctly, his boxster had 2003/04 axles which have the larger bolt holes on the cv joint but still use the small bolts. 97-02 axles only use the small 8mm(?) while the 03/04 can use 8mm or 10mm. 05+ use 10mm only
I have a 3.2 motor in my 99. Was running it with a 2.5 transmission, but stripped all the teeth off 4th gear. Has a 2.7 tranny in it now.
I run a cable throttlebody from a 99 996, with a custom intake tube. Added resonance flap wiring to DME and have my stock DME tuned by softronic. Maf is in a 3.25" tube from the 987 airbox.
