Hello.

I have a 2003 Mazda Protege5. It has already recieved a couple of bolt-ons including NGK iridium spark plugs, AEM cold air intake, Mazdaspeed exhaust, and Unorthodox Racing pulley. I have been thinking about bolting on a throttlebody from Cork Sport or Auto EXE. These are both available from Cork Sport, but it has not been easy getting dyno or flow bench data from them. No one else seems to make throttle bodies for this engine. The Cork Sport unit is reasonably priced; the Auto EXE part is expensive ($589.00). Does anybody have experience with either of these parts? Or, is there another aftermarket throttle body on the market for this car? If so, what do you think a reasonable torque/hp gain will be?

Also, I found some intake/ exhaust cams online, by Mazdaspeed. Has anyone done a cam swap, and if so, did you also replace the stock springs to avoid breakage or valve bounce? The hp numbers look good, but how much did idle quality deteriorate?

Thanks much.

 

Check the Vendor section for cams, there is a group buy going for an AWESOME set. As for the throttle body, Roddimus Prime is working on possibly adapting one from a different car for a cost effective mod. The cams will work with the stock springs, and there's a few different versions available.

 

beat me to it Dan....I wouldn't waste my money on the corksport TB.....it's a minimal gain so it should have a minimal cost. I'm looking to adapt a 65mm TB to our cars for about $150. THAT would be worth it.

As for cams....don't waste your time with the mazda cams you're looking at. Invest in ACTUAL performance pieces, not j-spec cams...The cams I'm selling are actual performance pieces.

Enjoy.

 

Thanks for the info. I looked into your information on the cams, and when you have it, I would look forward to seeing the dyno sheet. Honestly, I do worry about long-term durability of valvetrains running with aftermarket cams, so I will need to mull this one over a bit. Has anyone put any miles on a car with these cams yet?

Also, your throttle body idea sounds great. In order to get a meaningful gain, though, wouldn't the intake plenum need to be honed out? This appears to be tricky, due to the fact that the plenum is curved. What is your opinion here, would a gain still be had if the lip of the plenum was tapered to match the T.B.? This could easily be done with a dremel. Anyhow, regardless - please keep me updated on your throttle body idea. That's pretty cool. If you are successful adapting a larger one for $150, you'll have a customer lined up!

 

There is only 2 cars right now with these cams....a turbo mp3 and a P5. They are both very quick and doing just fine. I don't understand how any problems could arise from adding the cams in because they are designed to work as drop-in replacements for the stock valve train. Now, the RACE cams on the other hand will be sold in an optional valvetrain package to allow the motor to run up to 8K rpms. This will of course contain new springs and retainers.

As for the Stage 2 cams you should be more than fine for long term useage.

The TB idea I had to put on hold for a few weeks, but I'll start working on it here shortly. To achieve maximum effect you should every restriction removed from filter to intake valve....to do this you have to match sizing on everything. If you have a 65mm and a 50mm MAF then you're only going to breathe 50mm. I am going to be running the AEM ecu so I'll eliminate my MAF and use a MAP sensor instead so I will eliminate the huge restriction right there. As for the intake manifold....I wouldn't personaly take a dremel to it. If it's worth doing it's worth doing right. I'm hoping to source an extra IM and sending it off to Extrude Hone for stage 2 P&P and gasket matching. I would go on a limb and say that it'll be good for at least 20hp.