MAZDA Roadster - B6 with 4AGE 20V ITB - Throttle opening sound variations & Overrun Testing

[@hydro5580]

so nice... sounds great. How hard was the install on these? What else did you need to buy parts wise besides the ITB's themselvs?

[@batousan_]

It was fairly straight forward if you have some experience working on cars, a bit fiddly in places but you need to do a bit of wiring too depending on what setup you have. Standalone ECU is needed of course and some understanding of how to get the car going as you'll need a different strategy than using MAP. Its not really needed but I opted for VVT injectors which were cleaned and reconditioned. I also added a vacuum manifold to take a line from each throttle to feed the brake booster and a signal to the map sensor. You'll find yourself doing a few extra jobs while its apart, removing the inlet manifold gives you access to a lot of that side of the engine bay and its a good idea to check everything over and replace if needed. Theres an excellent thread on Clubroadster.net that has been a great resource for me so that would be a good starting point for research.

[@hydro5580]

@@batousan_ Sounds like a big job but eventually i want to do this 100%, thanks for the explanation and tips :) excited for the first mic'd up drive with your new setup 😂 theres only about 3 good sounding videos i like to watch witch are the RS Aizawa NA Roadster video from best motoring, the initial d NB8C Boost sound file, and your ARC Intake chamber vids 😋

[@higg1n5]

How was mounting and adjusting the throttle cable? From the Hummelink instructions it is noted that the 20v springs are lighter, how does the throttle feel? Did you add any additional springs like what is noted in the instructions?

[@batousan_]

I did a full sweep tps calibration in the ecu and saved file before fitting the throttles, then after fitting the manifold and throttles I fixed the cable stopper bracket to the 4th cylinder throttle and attached the cable as normal. Then checked the ECU tps sweep to compare to full range, on the pedal I was getting either 11-20% open at "closed" throttle and 100% at fully open or if adjusted max the other way it would be 3.4% and 93%. This wouldn't of course run well like this. I then simply removed the rubber stopper at the back of the pedal assembly in the cabin that affects the closed position and backed out the pedal stopper bolt to allow full open throttle, now in the ECU it shows full range. No extra springs on mine, I did a short showing this, the throttle feels good, light and snappy... kzbin.inforpVOqoNCrzk

[@higg1n5]

@@batousan_ great thanks. I’ll check it out.