I purchased an underdrive pulley, header downpipe from obx, mopar cam, and also have a custom 2 1/2 exhaust and intake. I was woundering if anyone would have a guess at what types of power gains i would get from this ?

 

What did you have to start with (year, engine, tranny)?

What is a header downpipe? and is there a header that goes with it?

Which Mopar cam?

Which CAI?

Which muffler?

Could be anywhere from no/negative gains to maybe 15 HP peak gains.

 

2000 auto sohc,
obx header and downpipe,
mopar cam P5007030,
Intake I made normal 3" tubing,
2 1/2 exhaust I made,
other little stuff.

 

This is my car without the r/t wheels I just bought.
[IMG]C:\Documents and Settings\Ed\My Documents\My Pictures\Kodak Pictures\100_0219.JPG[/IMG]



well i guess that didnt work

 

Your car stock would dyno maybe 90 whp.

The cam is similar to the Crane 0012, easily good for the advertised 6 HP, probably a little more. There is some mid-range power added, but most of it is top end (above your current power peak), which you aren't going to see with the auto (unless you install a manual valvebody, don't shift the stock one yourself...) and the stock rev limiter.

The OBX header would give gains similar to other shorties, 5-6 HP, again most of it mid range, below your power peak.

CAI hard to say, probably 5-6 HP with most of it up top.

Piping, probably nothing, particularly if it's crush bent instead of mandrel bent like the stock piping. The 2nd gen cat is a 2.5" inlet/2.25" outlet (based on reports, I haven't actually seen one...) and necks down to 2" for the non-Magnum cars. So if you've still got the part where it necks down, that's the restriction. If you've replaced it, then the cat outlet is the restriction. If you've replaced or eliminated the cat, then it's all fine and good, but really not worth much power. It just frees up restrictions for when you start getting into the 180+ HP range (crank HP). Any decent muffler (pretty much everything except a louvered glass-pack) is good for a 3-5 HP gain in most of the band for all SOHC's. A true straight-through would be even more.

I'm sure you realize you can't just add up max gains to figure out final results (aka ricer math). You've raised the RPM where your HP peaks with the cam and header (possibly above the shift point of your tranny), and added a good bit of power throughout the powerband overall. If you were to dyno it, I'd bet your peak would be somewhere in the 100-105 WHP range, and your powerband would be a little broader.

 

So what would it possibly be pushing at the crank.

 

I know im loosing more power to the wheels throught the auto, then a 5spd

 

Its pretty funny i have a friend with an si civic and i can take him stock no problem., with a 3spd.

 

also is there a way other then removing the engine to find out what the power is at the crank.

 

you do know that you can edit an old post so that you're not quadruple posting, right?

And there is no way to know how much you're losing between the crank and the wheel, short of tearing the thing out and sticking it on a dyno. It doesn't matter how much HP you've got at the crank. What really matters is how well you handle that power. If you're racing on a straight road, then yes, power TO THE WHEELS matters, not power at the crank. If you're racing on a winding track, then handling matters.

What crank dyno often won't take into effect is that your engine isn't able to breathe as it would on a road, sure they can be simulated, but that's not a real world application. Take your car on the road and see what it can do, but don't be stupid with it