Due to strange and strict car modification laws in HK...I am looling to modify my 99.9% stock Evo 9 GSR to increase the horses, hopefully to 300whp

I've read through the long list of modifications at the sticky and am wondering how I can achieve the target whp but at the same time, keep the engine bay almost the same as stock (look wise)?

 

For completely invisible power mods; cams (they can alter the vehicle sound though) and an ECU remap. Those are the only two I can think of off the top of my head. If you have a JDM evo 9, that should reach 300whp.

There are others that don't really add power (engine internals, headstuds etc).

You should be able to do a handful of other mods that look stock to the untrained eye.

I've heard about Hong Kong modification laws, they suck.

 

Stock frame turbo, certain exhaust manifolds, down pipe, LICP, cams..

You can also get certain stock parts ported.. There are also some stealth exhausts you can get also. You don't really need too much to reach 300hp..

 

Thanks for your reply. I shall look into ECU remap and cam first.
How about replacing the stock turbo? The turbo is somewhat not too visible, or...the stuff that goes with the new turbo will make the engine bay too modified?

 

You could copy my mod path, it looks stock except for the exhaust and I put down 400. Modify a stock intake box to allow for a different intake and filter to be installed, keep the stock heat shields, and the stock upper pipe.

 

In terms of a new air-intake box, will it affect the lower rpm range power delivery?

 

Which part of hk are u in. I was born there, now I live in the states. I know how crazy hk laws are, if they see something crazy, it'll get impounded in a heartbeat. Good luck

 

300 not too difficult to reach. HKS cams will give you an okay bump in power and they can be tuned so the lope sound isn't so noticeable. Which is what you want in this case. A set of GSC S1 cams might be okay too. MAP ported intake and exhaust manifolds. A tune. As for exhaust you need to really be picky and look for one that is a stealth version, with a high flow cat. Now to push it over the 300 a stock frame turbo upgrade. I'd say a MAP or BBK. Fp is out because they stamp the housings with an FP logo. A sharp inspector will catch it.

 

Some 272 Cams, Cobb Accessport(If you can find one for a CTA9), Ti-Headstuds, Test pipe (w/ welded cat shield), Downpipe, 02 housing, Ported hotside, Ported Intake Manifold, Ported Throttle Body, Ported Exhaust Manifold) a highflow filter, and like 800-1000cc injectors, fuel pump should do the trick?

 

^^ some of those will be seen. The inspectors in HK are muck worse than CA. You will have to get your car set up for ECU controlled boost. If its still as strict as it was even a manual boost controller is cause to impound.

 

Your 9 turbo will get you there. I'd say cams, tune and hard pipes should be ok. Paint the piped black IMO. I would work on exhaust. Get on youtube and listen to some exhaust. Something quiet, or with a silencer. Open up the flow on the exhaust.

 

I remember Ralliart in China is still up and running. If you have Ralliart in your enginbay you can argue is from the factory. Not sure if that would work

Also WORK can modify your factory exhaust so you can have a 3Inch exhaust all the way and your muffler is still OEM. It may change the sound though.

 

Injen's exhaust is quiet..quieter than the RRE stealth.

 

There was a video on youtube a while back about a shop that bolted up a fp green to a 100% stock evo and made 300whp (picking up 70whp over base runs).

 

still, FP stamps their name on the turbo.

get a tune first, see where you're at. You can get a drop-in filter for the stock box as well