Hello there. When I bought my car, never noticed that it came with a 70mm tb and apparently a ported manifold. The car ran at 1,200rpm idle and the a/c pulled a lot of power when standing, falling as low as 650-700rpm, making it really shaky, and a 2000rpm rev hang untill 0mph was reached. Tried moving the tps for different values and the car ran a little bit better, but it wasnt running right.

So, I bought a stock tb, changed it and readjusted the throttle cable and the car is running better. Smoother shifting and not acting up when using the a/c, 900-1000rpm idle and corrected the rev hang. As soon as you press the clutch, it falls to idle and stay there. Things that I noticed, its consuming more gas and lost a little torque (yeap, thats right). Now I need to drop another gear when slowing down to take a turn.

is there something Im missing? Here a picture of the tb. Seems to be a Honda one, ported and butterfly size increased

 

I've experienced some of those issues on various throttle bodies, it sounds like the one you had was severely out of adjustment. I've always been able to adjust out the issues you describe by adjusting the TPS sensor, and the throttle stop screw, along with Idle air control valve cleaning and a idle relearn procedure.

You shouldn't have experienced any MPG loss, I don't know why that would have happened unless the bored out throttle body leaned out the a/f ratios, but that would only have been at WOT, not cruise conditions. You definitely would have lost some throttle response going back to the stock TB, not likely a big torque loss but much less throttle response. Throttle bodies increase throttle response and that gives you the feeling of a stronger engine as you don't have to open the throttle as much to get the same level of power, hard to explain unless you've had a few of them to experience. I've had one on every Honda I've owned including the S2000.

 

Yeah, SOS uses a modded oem unit, so probably what that is and its probably the best option on the market for longevity and reliability. Ive had the same one for well over 100k miles, injected with all kinds of water/meth and never a problem. They do add power with the port job and throttle response of course so thats likely why you feel the loss going back to stock. As far as the tps or other trouble you were experiencing, who knows what the previous seller did to foul it up, but in my experience they are trouble free right out of the box and dont ever need adjusting. At least form SOS. Ive heard of issues with other aftermarket TB though.

 

Totally understand Zero, but that feel really did its job fooling me. Definetly have to give a little more gas to reach similar goals. And I think that might be the reason Im having a hard time adjusting to it and the reason Im affecting mpg. Definetly mpg was affected after the tb change, maybe as I say, since Im having trouble adjusting myself to the more relax feel of power than what Im used to with the 70mm.

Oh well, anyways it was throwing the car off so having it acting better is a plus over the 70mm. Maybe Ill keep it and try later or maybe Ill sell it and buy a Ballade later on, and getting it adjusted properly. Lets see.

Also, so I dont open a new thread on this, I have noticed since the beggining, when the car is hot and got driven for a while, I feel and hear the gas pump working louder. Im able to hear it from either inside or outside the car. Is this something normal for the car or I have maybe a bigger fuel pump since the cas was boosted and probably the PO left it there so he could save his time of getting it out?

Thanks for the reply!

 

yeah with larger throttle bodies you get more air quicker as the plate opens and more power with the same amount of throttle, so part throttle driving always feels much better. I've got the J's Racing TB on my Ap1 and it feels good, it's smaller than the one you had more than likely so your's probably felt even better and more responsive.

OEM fuel pumps make zero noise, willing to bet you have an aftermarket one in there as they will make more noise, almost a jet-like hum or whistle sound to them.

 

yeah with larger throttle bodies you get more air quicker as the plate opens and more power with the same amount of throttle, so part throttle driving always feels much better. I've got the J's Racing TB on my Ap1 and it feels good, it's smaller than the one you had more than likely, so your's probably felt even better and more responsive.

OEM fuel pumps make zero noise, willing to bet you have an aftermarket one in there as they will make more noise, almost a jet-like hum or whistle sound to them.

 

Thats exactly how it sounds. First, theres a hum for a couple seconds when turning the key on, then its quiet for some time. After 30min or so of running, it starts the humming/whistleing youre describing. Also, it clicks sometimes when clutch is slowly released and the engine feels like its going to stall, usually when trying to move from a slope.