yes, behind the maf is the main point. the jwt kit (like you mentioned) is designed to pull air from the egr system for n/a or draw through maf set ups, where the egr intake inlet is behind the maf. which will not work for most turbo kits that are blow through. if you T-ed the egr on the blow through maf set ups you would be getting unmetered air. you would have to weld in a nipple to run after the maf on this style turbo set ups. drilling the hole is just simple. besides, the throttle plate is brass and easy to fill. i had no reserves about drilling it 6 months ago, lol.

the jwt kit also ties into the evap line on the back of the manifold like you said, but the hole for the evap is larger than the 1/8" one i drilled in the throttle plate. it is not a perfect circle, but i would guess the opening to be more like 3/16" or a touch larger for the evap.

 

ok.... the JWT thingy doesn't work for me AT ALL and my car is a N/A tuned car... the only way to make my throttle work now (so far without drilling my throttle plate) is to adjust the ignition timings at the motec (higher number at below 900rpm) to keep the engine alive... the fluctuation is no more than 100rpm, but with the A/C turned on, the engine MIGHT die on the hot day or at a rapid decel with A/C turned on too. (car virtually becomes quite hard to drive even when during gear charge without blipping the throttle *with the A/C turned on)

cheers,

richie

 

The JWT modification also did not work on my car with APS TT.

 

Correction:

Just made a modification to the JWT kit, I actually made the hose a lot shorter... (probably just a bit shorter than 10 inches) and moved the "T" section at the factory vacuum pipe closer to the throttle body instead of at the middle... my idle goes up from 900rpm to 1000rpm now (I also cleaned up all the greasy stains inside the throttle body too)... and at decel, the rpm only goes down to around 600rpm instead of 500rpm (with the A/C turned on), most likely due to the extra air getting into the throttle body now when the throttle is shut?!

Damn that I should have got the cipher kit earlier myself, I will need to drive by my nissan dealer tomorrow to set the idle down a bit to 900rpm and it should be all good then I hope...

Scott,

Do you think by setting the target idle speed down to 900rpm from 1000rpm have a large impact on how the car operates now? since the throttle body is drawing extra air into the plenum while the throttle is shut and should keep the engine alive still, correct? It shouldn't matter where the car idles at? Please let me know what you think! thanx!

cheers,

richie

 

hey richie, all i can say is just play with it abit. try different settings with the motec and see what happens.

 

thanks Scott!

I should have posted the previous message this morning instead... because when I started up the car this morning (was going to go to work and went by my dealer), the car idles at 900rpm AGAIN... so I guess it idled at 1000rpm was something to do with me removing the throttle body last night and it tried to relearn it...

but the strange thing is that the car is a lot easier to drive now though and there is no sign of air leakage anywhere in the system and if there is, it will be in between the factory vacuum line and the breather hose, but that shouldn't affect anything at all really... so my conculsion to this cutting hose action is.... it might actually help creating a bit more vacuum to the sysem to pull more air into the throttle, and heck, it drives a lot better now for no reason.... I will give more updates later on if I find anything interesting or if I accidentally blow my engine "somehow"...

cheers,

richie

 

The code came back this morning. I reset it with Cipher. I'll do that Idle learn procedure to see if that solves it for good. If not, then I don't know what I'll do...

Later,

 

Update:

the engine surge come back today with light throttle (and now I am guessing it might be the faulty throttle body?!) but over all, the car drives quite nice with the modified jwt kit to my car... the car becomes a bit harder to cracnk start, but that should be dealt with easily with more tuning on the computer...

Madelinot:

Try to bump up your own idle with ciper to 850rpm or 900rpm or so... so the target idle speed is around where it sits now... give it a try, you might not have any error code after that since the target idle is set at or close to the actual idle... I am not too sure if this sounds logical, but i will try it with the cipher kit!

cheers,

richie

 

I just wanted to tell everyone that my idle problems when coming out of high rpms was solved by drilling the 1/8" hole in the throttle body. When pushing in the clutch after high rpms the car actually idles at 1200rpms for a few seconds then drops down to 800-900rpms. I am running sleeves, fully built and cams. It would stall out previously about 1/10 times. I have an extra throttle body so I figured what's the harm. It works like a charm.

 

Good to hear and thanks for the update

 

bringing this back from the dead

I just noticed that one of my boost hoses going to my emanage boost pressure sensor had come off (car isn't using the emange ultimate anymore, but I haven't fully uninstalled the unit yet so those hoses are still there)

Anyway that was giving the plenum access to the outside air thru that small hose and I noticed that the car was easier to drive and seemed to start up nicer than when I plugged the hose back in. Obviously a leak in the plenum to outside air is bad under throttle, but if it was on the throttle plate, that solves that, so here am I posting

just wondering for anyone with a 6MT and aftermarket clutch/flywheel if you've noticed the clutch engaging smoother because of the constant access to outside air thru the hole in the throttle plate?

My idle is already at 1100-1200 rpms, but since plugging the hose back in, the car is really harder to engage from a dead stop. At this point, I think I'll end up drilling the throttle plate

 

place a one way valve on that vacuum line. Air goes in but not out

 

Can someone show me where you are drilling the hole exactly. You can do it by picture, diagram or whatever. Thanks

 

I am about to do this to my car to see if it helps my jumpy idle.

 

did you guys notice any change in throttle response?