|
Tech Talk Technical Discussion About The Nissan 240SX and Nissan Z Cars |
|
Thread Tools | Display Modes |
12-17-2010, 12:06 PM | #1 |
Nissanaholic!
Join Date: Dec 2003
Location: In a place, near a river, over a lake
Age: 37
Posts: 2,415
Trader Rating: (22)
Feedback Score: 22 reviews
|
Snapped another throttle body - SR20DET - PICS
So here we go again, I broke another throttle body on my SR. The first time this happened, the #4 ate the screw, I lifted my head gasket and kicked a rocker in the head. After I switched to the "new" one I decided to weld the backs of the screws encase this happened again. Well luckily that move saved my motor and I just broke the axle again. Basically all components that are related are as follows.
Freddy Intake Manifold OEM throttle body assembly S14 SR cable pulley 240SX throttle cable custom base bracket. Here is a picture of that: Here is the carnage from the first episode. Now consider I'm not your typical "throw shit together" enthusiast. I like my car to work well and I plan for that in my build. I can't say it wasn't over pulling the stop the first time, b/c I honestly don't remember, but I will say I assure you that I set it up with good intention and adjusted everything appropriately; I thought. Found this in the #4 cylinder with a magnetic wand On the second throttle body I can assure you that there was ABSOLUTELY no chance I could have over pull the throttle body. I was very meticulous on the second install and was sure i had it adjusted well. Not to mention I also welded the screws to the center axle to be damn sure they couldn't dislodge. Like I said, that luckily saved the motor this time. The break was in the same place as last time and it doesn't look as though the welding had weakened the axle any. Here are a couple shots of that. I'm not sure what I aim to gain from this thread. Maybe it will be useful in the future to someone or maybe someone on here has dealt with this before and can provide some incite. Currently I'm sourcing another OEM throttle body and plan to weld the screws as before and install as I had it. I'll then set up an indicator and see if I can't measure some amount of deflection. It wouldn't be difficult to weld on a "spine" or some additional material but I just wouldn't have thought it would be necessary. I'm also planning to review the base bracket and see if that isn't part of the culprit. Any thoughts? Experiences? For reference, the car is tracked as a drift car and makes just over 400 to the wheels.
__________________
Fu*king ginger bread man stole my wallet... SHIFTlock_slide to side d3m3rs0n: if i have a baby im naming it Brandons Fault Emerson |
Sponsored Links |
12-17-2010, 12:58 PM | #3 |
Zilvia FREAK!
Join Date: Oct 2009
Location: socal, man!
Posts: 1,261
Trader Rating: (11)
Feedback Score: 11 reviews
|
you can use a G20 TB but you'd have to rearrange the TB cable guide...Thats what i used for mine when the butterfly decide to snap while my wife was stuck on L.A. traffic...lol
Atleast its newer thats all, Could run your $60 at the junkyard.. or FREE.. with this cold weather were having, go to your local yard with a big ass snow jacket.. HAHAHAHHA ;]
__________________
@dangerdamian |
12-17-2010, 01:08 PM | #4 |
Post Whore!
Join Date: Oct 2004
Location: San Francisco, CA
Posts: 5,998
Trader Rating: (13)
Feedback Score: 13 reviews
|
Awww fuck I would be PISSED if that happened to me.... Could it be temperature related like the cold and heat accelerating metal fatigue?
The other time it happened, was it around the same time of year. cause its FREEZING in Georgia ATL.... sheesh
__________________
Turn and Burn! |
12-17-2010, 01:50 PM | #5 |
Zilvia.net Advertiser
Join Date: Nov 2005
Location: Michigan
Age: 36
Posts: 5,574
Trader Rating: (16)
Feedback Score: 16 reviews
|
Seems like you don't have a stop to your throttle cable/pedal, causing you to put a lot of stress on the throttle shaft when you are smashing that pedal to the floor, haha.
Fab up a stop for the throttle pulley. Problem solved.
__________________
Build: http://zilvia.net/f/showthread.php?t=643065 Friends don't let friends buy knock-offs. |
12-17-2010, 02:06 PM | #6 | |
Nissanaholic!
Join Date: Dec 2003
Location: In a place, near a river, over a lake
Age: 37
Posts: 2,415
Trader Rating: (22)
Feedback Score: 22 reviews
|
Quote:
Care to share any pictures for a reference. I might also be interested in it too. Yeah and it happened in the middle of a 4th gear pull on the highway; sorta reminded of those Supra videos you see when the motor grenades. Similar times but I can't put my finger on exactly when it happened. The marking on the valve plate seems to suggest it wasn't just the other day. That axle has got to see the full spectrum of cold-heat regardless of outside temperatures.
__________________
Fu*king ginger bread man stole my wallet... SHIFTlock_slide to side d3m3rs0n: if i have a baby im naming it Brandons Fault Emerson |
|
12-17-2010, 02:41 PM | #7 |
Post Whore!
Join Date: Apr 2004
Location: Houston, TX
Posts: 2,701
Trader Rating: (16)
Feedback Score: 16 reviews
|
Make your TB bracket out of something with some give. Use like 0.063" thick aluminum instead of the 1/8-3/16" stuff you're using now. This will give some flex there to reduce stress on the throttle shaft.
__________________
S13 Hatch - Goes around tracks quickly DEFSPORT |
12-17-2010, 03:14 PM | #8 |
Post Whore!
|
I believe switching over to the Q45 throttle body has alleviated a lot of high HP guys' problems with this same scenario.
|
12-18-2010, 12:45 PM | #10 | ||
Nissanaholic!
Join Date: Dec 2003
Location: In a place, near a river, over a lake
Age: 37
Posts: 2,415
Trader Rating: (22)
Feedback Score: 22 reviews
|
Quote:
Quote:
Na, I'm pretty sure it wasn't over pulling the stop but ya know its hard to tell now. I'll have to verify that on the next install. I wonder what the difference is between the skinny pedals' sweep and the length of pull exposed at the end of the pedal. I mean surely there is a difference given its a 240sx cable an SR throttle body, and an S14 Sr pulley.
__________________
Fu*king ginger bread man stole my wallet... SHIFTlock_slide to side d3m3rs0n: if i have a baby im naming it Brandons Fault Emerson |
||
12-18-2010, 01:42 PM | #11 | |
Post Whore!
Join Date: Dec 2006
Location: Misawa, Japan
Posts: 6,815
Trader Rating: (8)
Feedback Score: 8 reviews
|
Quote:
I dont think that would snap the shaft, since what your pulling on has the stopper, (unless its pulling at an angle) Now if his Throttle plate is getting hung up or binding before the Throttle pully hits the stopper then yeah I could see the shaft snapping
__________________
後輪駆動車1番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit |
|
12-18-2010, 04:04 PM | #12 |
Leaky Injector
|
Your throttle pulley is on wrong. Placing the cable out that far is likely putting excessive bending forces in the axle when its resting on the stop.
I'd consider flipping it or making a pedal stop. |
12-18-2010, 05:47 PM | #14 | |
Post Whore!
Join Date: Apr 2004
Location: Houston, TX
Posts: 2,701
Trader Rating: (16)
Feedback Score: 16 reviews
|
Quote:
I have a FReddy manifold with the stock S13 pulley still on there. I just built a bracket out of some bent 1/16" 2024 aluminum angle. It noticeably flexes before the pedal stop hits, but I've never had a problem because it basically acts as a limiter on how much force can ever be applied to the throttle body.
__________________
S13 Hatch - Goes around tracks quickly DEFSPORT |
|
12-18-2010, 08:25 PM | #15 | |
Post Whore!
Join Date: Dec 2004
Location: Poconos, PA
Age: 39
Posts: 8,030
Trader Rating: (58)
Feedback Score: 58 reviews
|
Quote:
Ultimatly, I don't think there is a true 'reason' to this happening. I'm sure some of the smarter guys here could form up some reason in relation to pull and the force involved and that stuff (above my head!) but it's still a relative mystery. With that said, I am going with a Tomei TB (got it super cheap) this winter to ward off any potential problem. Maybe I read to far into stuff, maybe(gasp) at times I follow forum superstition, but It's just a sake of mind issue.
__________________
Want Air Conditioning in your SR20 Swapped car? Check out www.sr20acbrackets.com for more information! Quest Alternator Conversions for SR20! Check my Group Buy! Tired of lousy internal gates? Go external wastegate with one of my manifolds, Check out my group buy |
|
12-18-2010, 10:01 PM | #16 | |
Leaky Injector
|
Quote:
You have that pulley on backwards dude. I don't have an SR but on all the Nissan engine's I've dealt with, that pulley goes on the other way so the cable is closer to the TB itself. It's sticking out quite a bit farther than it should. You're prob putting the shaft in bending whenever it hits the stop, and you're moving that lever arm out by installing the pulley wrong, which causes the shaft to fail since it wasn't design for that amount of stress. I don't think the cable bracket yall talkin bout makes that big of a difference. |
|
12-19-2010, 07:42 PM | #17 | |
Nissanaholic!
Join Date: Dec 2003
Location: In a place, near a river, over a lake
Age: 37
Posts: 2,415
Trader Rating: (22)
Feedback Score: 22 reviews
|
Quote:
__________________
Fu*king ginger bread man stole my wallet... SHIFTlock_slide to side d3m3rs0n: if i have a baby im naming it Brandons Fault Emerson |
|
12-19-2010, 08:25 PM | #18 |
Leaky Injector
|
Well then that pulley wont work. If you were to compare the length of the moment arm of the s13 pulley on the s13 throttle body, with the length of the moment arm of an s14 pulley (installed backwards from the way its installed on an s14 throttle body) installed on an s13 throttle body, the way you have it, its about 4 times longer and the bending loads are 4 times more.
Since I'm blind and cant see that this is the only configurstion that will work the easiest thing to do, is make a pedal stop. This will limit the force pulling/bending on the end of the axle once its fully rotated and resting on its stop. Or you can disregard my advise and do nothing and keep hoping for a different result. |
12-19-2010, 08:33 PM | #19 |
Zilvia Addict
|
"Insanity is doing the same thing over and over again but expecting different results."
I am guessing you have already tried moving the mounting point for the throttle cable? |
12-19-2010, 08:43 PM | #21 | ||
Nissanaholic!
Join Date: Dec 2003
Location: In a place, near a river, over a lake
Age: 37
Posts: 2,415
Trader Rating: (22)
Feedback Score: 22 reviews
|
Quote:
Quote:
Anybody have any pictures of an S14 SR throttle body?
__________________
Fu*king ginger bread man stole my wallet... SHIFTlock_slide to side d3m3rs0n: if i have a baby im naming it Brandons Fault Emerson |
||
12-19-2010, 09:11 PM | #22 |
Leaky Injector
|
You are right about how the s14 pulley is installed on an s14 throttle body but the pulley sits closer to the throttle body on the s14 than the s13. See the "free body diagram" for clarification on what I mean by bending. The throttle cable pull is much closer to the throttle body on both the s13 and s14 from the factory than what your working with. The yellow shows an exageration of how the axle is bending once the stop is reached. The OEM s13 pulley is deeply concave to move the pulling action closer to the throttle body.
|
12-20-2010, 07:27 AM | #23 | |
Nissanaholic!
Join Date: Dec 2003
Location: In a place, near a river, over a lake
Age: 37
Posts: 2,415
Trader Rating: (22)
Feedback Score: 22 reviews
|
Quote:
The main objective behind this thread is to bring to light the problems with this commonly recognized quick solution for the GReddy style manifold. Thanks for the illustration, and I'm quite aware of what you are describing, but like I said, this is/has been a common solution for this manifold. Apparently more support is needed for this assembly. My new throttle body will be here in a few days. I'll get some real numbers and see if its an adjustment issue or if more support is needed. I think the pulley is a great solution but might require additional support.
__________________
Fu*king ginger bread man stole my wallet... SHIFTlock_slide to side d3m3rs0n: if i have a baby im naming it Brandons Fault Emerson |
|
12-20-2010, 07:50 AM | #24 |
Post Whore!
|
I believe Steve Shadows on here went to a Q45 TB and all his problems went away.
The Q45 TB does indeed have a larger bore, but I think the axle shaft is also a lot thicker. IIRC he had a thread on this forum (if not, then it was probably on Fresh Alloy) explaining what was going on and the results, with pictures of course. |
12-20-2010, 09:40 AM | #25 | |
Post Whore!
Join Date: Dec 2004
Location: Poconos, PA
Age: 39
Posts: 8,030
Trader Rating: (58)
Feedback Score: 58 reviews
|
Quote:
Ahhh I see what they are saying about your pulley, it's simply way to far over to work as OEM...there ahs certainly got to be an additional 'stress' on the length of that rod being so far over, compared to where OEM is. Here are pics of mine...granted not the best, but I've NEVER had an issue: Pics from a few years back: Edit: Here I zoomed in (I know quality sucks, but you can see haha)
__________________
Want Air Conditioning in your SR20 Swapped car? Check out www.sr20acbrackets.com for more information! Quest Alternator Conversions for SR20! Check my Group Buy! Tired of lousy internal gates? Go external wastegate with one of my manifolds, Check out my group buy |
|
12-20-2010, 12:10 PM | #26 |
Nissanaholic!
Join Date: Dec 2003
Location: In a place, near a river, over a lake
Age: 37
Posts: 2,415
Trader Rating: (22)
Feedback Score: 22 reviews
|
yeah I'm thinking I might machine a support bearing; with a brass or bronze journal to support the outer end, or add some strength to the center shaft. I see you made a bracket they allowed you to retain the S13 pulley. I'll keep that in mind, since I know I've got an S13 one around here somewhere, if I can't mfg. a more rigid setup.
__________________
Fu*king ginger bread man stole my wallet... SHIFTlock_slide to side d3m3rs0n: if i have a baby im naming it Brandons Fault Emerson |
12-20-2010, 01:55 PM | #27 |
Post Whore!
Join Date: Dec 2004
Location: Poconos, PA
Age: 39
Posts: 8,030
Trader Rating: (58)
Feedback Score: 58 reviews
|
Yea it took a few trys, but I got it sorted. Made one for my roomate as well. I'll take better pics and measurements tonight for ya
__________________
Want Air Conditioning in your SR20 Swapped car? Check out www.sr20acbrackets.com for more information! Quest Alternator Conversions for SR20! Check my Group Buy! Tired of lousy internal gates? Go external wastegate with one of my manifolds, Check out my group buy |
12-20-2010, 07:03 PM | #28 | |
Nissanaholic!
Join Date: Mar 2006
Location: Philadelphia suburbs
Age: 40
Posts: 2,347
Trader Rating: (7)
Feedback Score: 7 reviews
|
Quote:
I just installed a new KA throttle cable on an SR throttle body, S14, and I KNOW I set it up properly.... When the throttle is fully open (verified by a second person), the pedal is NOT touching the pedal stop. I guess the SR throttle is smaller than the KA one, and thus requires less pedal throw to fully rotate 90*. I plan to install a piece of 2x4 or something on top of the pedal stop so that the pedal JUST hits the stopper as it opens all the way.
__________________
Daily driven |
|
12-21-2010, 06:52 AM | #29 |
Zilvia Member
Join Date: Apr 2010
Location: New York
Age: 46
Posts: 221
Trader Rating: (2)
Feedback Score: 2 reviews
|
Out of all of this im thinking the best and cheapest remedy(except the 2x4 behind the pedal) would be to fab up a bracket that locates the throttle cable back inwards in order to utilize the stock throttle pulley again. Am i missing something? Im hoping to finish this small but so important detail on my car today.
|
12-21-2010, 07:24 AM | #30 |
Nissanaholic!
Join Date: Dec 2003
Location: In a place, near a river, over a lake
Age: 37
Posts: 2,415
Trader Rating: (22)
Feedback Score: 22 reviews
|
^ Likely. It might just be that the S14 throttle body pulley just induces too much side loading on the shaft, being that sits that far out. If what Jspaeth says is true, its possible that the pedal will allow for an over rotate scenario and just break the shaft... Either way, what ever I put back in the line of fire, I assure you those screws will be welded. It was too much of a headache to do a head gasket for this; and I lucked out with my damage....
My throttle body should be here any day now... I'll know something more by then.
__________________
Fu*king ginger bread man stole my wallet... SHIFTlock_slide to side d3m3rs0n: if i have a baby im naming it Brandons Fault Emerson |
Bookmarks |
|
|