I have read that this kind of modifying would make 5% more power and reduce fuel consumption. What do you think?

I dont know about 5% more power on the stock engine, but the butterfly valve in the throttle body can definately be improved, that looks pretty much like what i've done to mine, though i was thinking it could probably benefit even more with something, like a smear of silicon i suppose, where the plate reaches the round shaft so there less turbulance on the airflow at WOT. If other things had been done to the engine to the point that it was a restriction i might be inclined to say otherwise but maybe 1-2% on a stock engine if that

It wouldnt reduce fuel consumption as by knife edging the plate and filing the screws down your allowing more air to go through, and in turn more fuel, which would reduce ur fuel economy, and also it would only really make a difference at WOT. I'd imagine it'd give no better or worse economy execpt when at WOT when it'd be a bit worse

I'll let you know when i put mine in.

I'm put my modded throttle body in today, going to tighten it all up tomorrow morning and set it up, will let you know how it goes after its done.

I am going to clean up my TB tomorrow. Is there some specific Nm-value for the bolts or do I just tighten them as tight as they go.

Fuse wrote:I am going to clean up my TB tomorrow. Is there some specific Nm-value for the bolts or do I just tighten them as tight as they go.

Those small screws, make sure you put some loctite into them, nothing else that I'm aware of. Don't tighten too much, usually bends/brakes if tightening with all muscles

The bolts dont need to be godly tight, i pretty much went hand tight on the 3 bolts and then a quarter turn, as the originals werent on excessivly tight, though when i had it all hooked up the car was idling at 2100-2150 rpm. Took me half an hour to figure it out, the nyloc nut that attached the throttle to the throttle body was too tight, it was only when i went to remove the throttle body to inspect it that i noticed it. you should tighten it up to the point that you should be able to hear the internals clik, then use that idle adjust screw behind it to fine tune it. After that the idle was down to 1300rpm, i'm thinking the relay that bumps up the rpm to compensate for aircon is stuffed, as when i turn the aircon on it puts it smack bang on 900rpm. might have to modyfy my original one and put it back in. Also i replaced the ducting from the airmeter to throttle as my spare didnt have a crack in it and was generally in better nic.

Anyway i went for a drive, and as i thought pretty much no improvement, though i'd be guessing with other things done to the car it'd be more pronounced, though i will note the engine did sound faintly smoother midrange, but that could have been the replacement pipework also. The other thing i was thinking is maybe the ECU hasnt yet adapted to the modification if it is a self learner. I think next will be the insulated manifold gasket to keep the intake cooler, and maybe seeing if i cant put a small injector where the EGR hooks up to the manifold and run water injection through that instead, i'd expect that would run much cooler than recycling exhausts and also if my understanding of water injection is right it wouldnt be at the compromise of emissions.

How are you planning to control water injection?

I think that it is not good to pour water into engine at idle

I have cold start injector just sitting in there, nowhere to connect it, then I have come to think if I will get 3-5bar pump for it, little relay and wiring and voila, I do have water injection. Mixture of 50% water 50% methanol should do the trick. I can control it with my megasquirt, but I'm not yet sure if I will build that system. We do have long winter, here is still snow and actually it was rainging snow at morning
-20C and water injection sounds not too good combination

Water injection:

Aquamist

The system works best on turbocharged engines but I think it will do some good on N/A engines.

*dreaming of a chipped 2.3 turbo with water injection*

It'd do good on a modded NA engine, when u start talking high boost(turbo) or high compression (NA) detonation and heat become serious issues. Water injection should help in both areas. a means of controlling it would have to be done whether its activated by an RPM or throttle position switch, i dont know , i just tossed the idea out there.