J richard

Ok here's the deal, waiting on finishing the 964 build in NASA ST3 but in the meantime wanted to get some points in class so I'm running the specbox in ST3 on Hoosiers. The thing will hang with most the field in the twisties, and with the tight tracks on the local schedule the big hp cars don't see too much advantage. First weekend was a blast, pretty sure I'd get my *** handed to me but managed two 3rd places and in the middle of the GTS3 crowd. But as you can imagine lack of power is painful on the straights.

So without swapping engines is there a way to get a few more ponies out of the 2.5? Thinking headers, intake, chip and a dyno...but don't want to screw with it if there's no real gains to be made. The car already has a open twin exhaust and will return to specbox duty afterwards...

Thoughts? Real experiences?

sbelles

You can get some with an ECU reprogram by raising the rev limit. When I had a 3.4 in a 986, we had the limit at 7900 without a problem. I would think you could go to at least 7200 with the 2.5.

jdistefa

You might get 5-7 hp out of headers but at what cost?

JCP911S

Maybe money is no object, but frankly, I'd invest in your end-game car, and just use the Boxster for practice... sounds like you're doing ok with it.

IMHO, HP is a crutch to mask poor technique... nothing makes you a better driver than driving a good handling low HP car against more powerful competition...

You really learn how to manage track position, and extract every ounce of speed through the turns... then when you get the extra HP, you know how to use it... and frustration is always a great teacher...

Have fun.

jrgordonsenior

By far the easiest and cheapest way to dramatically improve HP is to switch to a 99'-3.4 throttle body. It's the only year the 996's had a cable TB and it's identical to your 2.5 TB except it's bored out in the middle about 10mm. No need to change anything just plug-n-play. I tried one on my SB years ago and was surprised how much difference it made.....

The other things I'd consider is switching to 3.6 exhaust manifolds as they're larger (3.4's not so much) and cheap, and a good flash to take advantage of your new intake flow couldn't hurt either....

Ritter v4.0

[QUOTE=jrgordonsenior;11069523

The other things I'd consider is switching to 3.6 exhaust manifolds as they're larger (3.4's not so much) and cheap, and a good flash to take advantage of your new intake flow couldn't hurt either....[/QUOTE]

Do you mean OEM (used) or after market?

jrgordonsenior

Dave I meant used OEM as they're dirt cheap and have significantly larger ports than a 2.5. Even better is the 997-3.8 manifold which is what I use...

J richard

Thanks jr that's the kind of thing I was looking for.

jdistefa

That's it, I'm gonna put 3.6 headers on my specbox.

Carrera51

I've heard about swapping the throttle body. Would think bigger headers would help also. The stock 2.5 headers are tiny.

gums

You're right about that, JCP, but I can also tell you (from experience!) that racing against more powerful cars can get frustrating, especially when you are out-driving your opponents and still falling behind. Without realizing it, it can also get a bit dangerous if you find yourself over-driving and taking chances to keep up. Especially in traffic.

J richard

I'm thinking TB, headers chip and a tune will give me what I'm looking for. The challenge will be not dropping the bottom out of the torque, it has so little to start with...

Gary R.

I would just ask Streak what he does....

Ritter v4.0

Short gearbox will feel like +50hp

JCP911S

Yeah, tell me about it... prey for rain.