Throttle Body position on JRSC

[jeepinbanditrider]

I've got an M45 on my car along with a TDR Intercooler. The increased throttle volume pretty much makes it to where I have to turn the idle up to around 1500 RPM to get the car to idle without the idle droop killing the car on decel especially with the AC on. I've seen a few threads on other boards where a dual throttle body setup was run which eliminated the idle droop problem but required setting up 2 throttle bodies and making a pulley overlay to go ontop of the stock throttle pulley.I've read where other folks have moved the throttle body back to the stock position but this makes for LOTS of noise, and from a few posts I've read a few cases of the intake tube joints poping off when getting off the throttle. I've also read of possibly adding a BOV into the intake tract on the supercharger side to keep the boots from popping off when closing the throttle.I'm hoping some of the great minds on DFWMiata board have some ideas for me lol. I can live with the car idling at 1500 if I need to but would like to have a stockish feel when driving the car around if you know what I mean.

[trickyrix]

Jeff_man has his TB in the stock location with a blowoff valve to prevent intake piping from popping off when you slam the throttle shut. Yep, it's loud, but apparently effective.

[jeepinbanditrider]

That's one of the options I was looking at. It requires a BOV be welded into the pipe between the SC and the IC.

[trickyrix]

Yep. I don't think there's an "easy" solution to it... but maybe one of our other SCers will chime in.

[titanescape]

I have the exact same problem with my M45 but I'm running a JR Air to Water IC. I'm idled up as well and it still wants to die on deceleration. If I stay off the clutch till she almost dies then go to neutral it helps but in a parking lot it sux!!! If someone has an answer...please let me know!

[Titus]

A full ECU using a MAP sensor in place of the stock AFM/MAF makes this problem disappear

[jeepinbanditrider]

700 to a grand later lol :) I'm trying to keep from having to drop a grand on the problem. Trying to find some kind of pre-fabbed overlay pulley for a dual throttle body kit has been a nogo. MX5NUTZ in the UK used to make one but as far as I can tell they don't anymore.

[titanescape]

The only fix I have is when it cools down because I never run the AC..so problem is fixed. It drives me nuts but I guess I will deal with it for the next couple of months.

[Jim m]

Somewhere in my past... probably when the EPA began to kill cars in the early 70's... I had a car with a small dashpot (damper) for a throttle stop. It slowed the last little bit of throttle travel which kept the engine running if you closed the throttle quickly. It may have only engaged when the air conditioner was on. Sorry I don't recall more, it was probably on a company car that just got driven. Or, maybe on a '75 Camero. I'm bettin' some of you are ingenious enough to decide if it would be a solution.

Jim

[jeepinbanditrider]

The stock throttle body on the NA Miatas (1.6 not sure about the 1.8 models) has a dashpot. I removed mine becuase it did no good and I couldn't reach the mechanical idle screw with it still attached.

[POS Racing]

The stock throttle body on the NA Miatas (1.6 not sure about the 1.8 models) has a dashpot. I removed mine becuase it did no good and I couldn't reach the mechanical idle screw with it still attached.

The 1.6 needs that dashpot.

http://www.miatamania.com/Shop/ViewP...eIndexID=33179

Does your 90-93 Miata simply stall as you lift your foot off the gas and come to a stop? If the answer is yes, this little unit is probably to blame. Its purpose is to slow down the travel of the throttle plate which keeps the car from stalling. As the unit wears it allows a sudden closure of the throttle plate which temporarily chokes the engine for air and a stalled engine is the result. Supercharging the 90-93 Miata seems to worsen this problem. Save yourself the embarrassment and hassle of a stalled motor and replace this part today.

[Rob®]

The 1.6 needs that dashpot.

Correct. I should have a spare if you got rid of yours and want to give it a shot.

I also agree with Titus though. I would go that route before anything else - you will gain more in the long run with a tunable ECU. $400 and you can have my LINK :) Really though, if you buy a *good* BOV, a coupler designed to mount it without welding, you are looking at close to $300 after shipping. You can recirc some BOVs (namely the HKS SSQ) so you don't have to deal with that noise if you don't want to, but that will run you a bit more as well. You're not quite half way to a brand new MS3 at that point, but you're ballpark a used MS2...

[Titus]

You might want to go back and re-read this thread... several of the issues in this tread were discussed there.

[driftdevil]

Go on the turbo board and you can pick up a used ms for around $300 usually. I've got the same issue and bought an ms1 from there for $275 to fix the problem.

[jeff_man]

Every one above

Jeff_man has his TB in the stock location with a blowoff valve to prevent intake piping from popping off when you slam the throttle shut. Yep, it's loud, but apparently effective.

That's one of the options I was looking at. It requires a BOV be welded into the pipe between the SC and the IC.

Bov is not required unless you are running high boost and/or like to run at max boost all the time. the bov prevents screw turbulence at high boost, how high is high well i have not figured that out yet. But who cares BOVs are cool.

A full ECU using a MAP sensor in place of the stock AFM/MAF makes this problem disappear

not 100% true, still had idle problems after map and stand alone. was better after a lot of hours making it work but not magically fixed.

Go on the turbo board and you can pick up a used ms for around $300 usually. I've got the same issue and bought an ms1 from there for $275 to fix the problem.

get an MS3

I have everything you need to relocate your tb, the JR dummy is to big to fit on the blower and i have some billet aluminum dummies already made. Was thinking about a 2xtb with a drive by wire tb on the blower, if you feel like spend some cash on a cool idea let me know. Can also help you with a analog 2xtb setup if that's how you want to do it.

[jeepinbanditrider]

Analog would be fine with me. Sounds extremely loud in the video at idle. Did you experience a drop in gas mileage by moving the TB back to the stock position? I've heard you get a decent drop in mileage by moving it over.

[SirHustlerEsq]

+1 for MS3, but for most people here MS1 will get the job done as it has on my car. $700 is a lot of money to me, but I promise the car will drive better than it did from the factory when someone with a clue tunes it.

[jeff_man]

Analog would be fine with me. Sounds extremely loud in the video at idle. Did you experience a drop in gas mileage by moving the TB back to the stock position? I've heard you get a decent drop in mileage by moving it over.

Picked up over 10hp and had to get bigger/better injectors. I have to idle why someone would think this would drop your mpg and as i under stand it your running the car more effective so would think you would get better mpg but your talking 100ths of a gal ether way.

Very loud but very cool.

also still have not found a car to test if you can run a single tb with a maf.

[jeepinbanditrider]

I may have to give it a shot in the stock location and see what happens. I like supercharger whine :)

[jeepinbanditrider]

I'm sittin here at work waiting for a plane to take off and I was thinking about how the bypass valve on the supercharger works. When you relocated the throttle body to the intake manifold did it make the bypass valve stop functioning?