CableSrv Posted February 29, 2016 Share Posted February 29, 2016 Ok, so I bought DSS's kit to replace the half-shafts with 930cv's and includes the inner stub axle for the STI R180. I bought a used STI R180 from eBay and looked inside to verify that it was indeed a Torsen unit. Finally got them all replaced and took her for a drive and everything seemed normal under normal driving conditions. So figured I'd see how well the diff would handle the power of a LS1 and stomped on the throttle. Tires broke loose like normal and everything seemed fine for a little while, then a weird popping/grinding noise started happening anytime I am under major power. Car drives normal under normal conditions... but anytime I apply power that would otherwise cause the tires to break loose, this horrible grinding/popping noise occurs. Could it be the 930cv's ? Could it be the Torsen LSD? Could it be the 930 conversion input stub axles for the STI R180? Something is making a horrible noise under power but otherwise no noise at all driving normally? No clue what the hell is going on and I probably need to drop the diff again and check inside... but has me worried that the LSD went bad? or that the 930cv's are junk from DSS. Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 29, 2016 Share Posted February 29, 2016 No answers here, but how big are your tires, how dry were the roads, how much torque do you think your LS1 is producing, and what gear were you in when you stomped the throttle? And was there anywheel hop? Just to fill out the critical data list. And, just for fun, what happens if you give it gas in reverse? Might give a clue. Quote Link to comment Share on other sites More sharing options...
CableSrv Posted February 29, 2016 Author Share Posted February 29, 2016 Stock engine, with 3in exhaust and JTR's cold air intake.. so probably around 310-340? Roads are dry but I have tiny tires 195/50r14? Didn't feel any wheelhop, it was pretty smooth the first burnout however ever since then is when I get the clunk. I have never tried a reverse burn out... but I can try? tho noise definitely comes from behind me. I do have RT mount with polyurethane mount. Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 29, 2016 Share Posted February 29, 2016 I'd crawl under and look for loose parts first. Could be the burnout had nothing to do with the noise. Interesting setup. People will be curious. Some have already said the R180 is too small for that power level. Post pictures. Quote Link to comment Share on other sites More sharing options...
CableSrv Posted February 29, 2016 Author Share Posted February 29, 2016 Only reason I went with the R180 from the subbie was because I've seen conversions done to make them RWD only and push 500hp to them. It seems it's a popular thing to do for drift cars. However that said I don't plan to do clutch dumps and never have. I do however stomp on the gas, which with the torque a ls1 has, makes for easy tire slippage. Then having tiny ass tires also helps! Quote Link to comment Share on other sites More sharing options...
seattlejester Posted February 29, 2016 Share Posted February 29, 2016 I too am worried that may be too much hp. I've read a couple of those builds, and it seems like they either go through a couple of diffs/have an aftermarket stronger differential/or have a gradual boost/boost by gear type of setup. Quote Link to comment Share on other sites More sharing options...
CableSrv Posted February 29, 2016 Author Share Posted February 29, 2016 Well this diff has to be stronger than my stock R180 since it only has 25 spline inputs and only 2 pinions vs 27? spline and 4 pinion + Torsen lsd. And my stock R180 had no issues currently handling the LS1, however the halfshafts on the other end are very close to being grenades. Not sure why you guys think 300-340 is too much for a R180? STI's typically get boosted pretty easily to those power levels and beyond. Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 29, 2016 Share Posted February 29, 2016 Not sure why you guys think 300-340 is too much for a R180? STI's typically get boosted pretty easily to those power levels and beyond. It's just popular opinion. You're the guinea pig. Report results. So far you're supporting the prevailing view. R180 > LS1 > burnout > horrible noises. Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 29, 2016 Share Posted February 29, 2016 Not sure why you guys think 300-340 is too much for a R180? STI's typically get boosted pretty easily to those power levels and beyond. Not a Subie expert either, but aren't those boosted numbers from AWD cars? Divide by two? Quote Link to comment Share on other sites More sharing options...
CableSrv Posted February 29, 2016 Author Share Posted February 29, 2016 Some reports are AWD and some are from RWD conversions. Quote Link to comment Share on other sites More sharing options...
CableSrv Posted February 29, 2016 Author Share Posted February 29, 2016 But agreed, I need to look into the R180 and see what is going on. Just odd that it behaves normally under normal driving conditions and only acts up under tire slippage. Quote Link to comment Share on other sites More sharing options...
fyanrudger Posted February 29, 2016 Share Posted February 29, 2016 4:00 mark may explain why it's okay in normal conditions versus locked. Quote Link to comment Share on other sites More sharing options...
CableSrv Posted February 29, 2016 Author Share Posted February 29, 2016 Ok so bigger question.. with what problem I stated. Is it at all possible that the CV's would cause this type of issue? considering it drives normally under normal throttle can I eliminate them as a possibility and just hunt down the LSD unit as the culprit. I plan to take the diff out again this weekend and see what I can find. Quote Link to comment Share on other sites More sharing options...
CableSrv Posted February 29, 2016 Author Share Posted February 29, 2016 http://www.subaru-global.com/assets/files/a4/8c18f73c874c42b072200acb14397a.jpgthis is what subaru's Torsen's look like. Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 29, 2016 Share Posted February 29, 2016 Many would say that you have a whole set of weak links, from your 240Z hub axles, through the 930 CV's, to the R180 (small ring gear) diff (used - who knows what the PO did to it). What you're really asking is a general question about a how Type B (I just found this, see below, not an expert) Torsen type differential fails. "How do Torsens fail?". If the Sti R180 is that style (assume that you saw those parts when you had it open). https://www.jtekt.co.jp/e/products/lsd.html Quote Link to comment Share on other sites More sharing options...
Chickenman Posted February 29, 2016 Share Posted February 29, 2016 (edited) Obviously, draining the fluid and checking the magnet for metallic pieces or very fine magnetic " Fuzz" is also a good idea and will give you a good indication of any problems. An quick and easy way to check a Torsen is to put the rear up on jack stands and have the car in neutral. Spin one wheel by hand. The other wheel should spin in the opposite direction like an open diff. Feel for any roughness or noise from the diff. This will show any damage to ring and pinion. Then, while spinning one wheel by hand, have a friend put a light load against the the other wheel. This will cause the worm gears and sector gears to rotate. Any graunching, locking, roughness or noise will indicate damaged gear or worm or sector gears. Damaged Torsens can work amazing well for a fairly long time in straight line acceleration, while slowly eating them selves to pieces when you turn corners. The Worm and Sector gears are the highest load points. Those often fail because of high shock loadings (Avoid doing burnouts with a Torsen ) or because the support shafts start to ovalize the holes in the diff carrier. The Worm gears then try and " walk " away from the sector gears and it's a slippery slope to failure from there on. Torsens are not good diffs for a Drag car. Awesome for corner carvers though. The smaller the ring and pinion is, the smaller the internal gears have to be made so that the diff carrier assembly can fit inside ring gear. Smaller components ( worm and sector gears ) cannot " reliably " handle the placed through them. Anything under 8.2" in R&P diameter gets iffy for Torsen reliability with big engine Torque and sticky tires. I believe the R180 R&P is approx 7" in diameter. Combine that with an LS1 and burnout... well I think you get the picture. I Autocrossed/Hillclimbed a high HP 1986 Camaro in the early to mid 2000's with a Torsen and communicated quite extensively with Zexel Torsen on their design for the GM 7.5" and 7.625" . Zexel had a real design problem with the durability of the gears and carriers in these cars. GM 10 bolts with a ring gear Diameter of 8.5" , Chrysler diffs and Mustang diffs with a gear diameter of 8.8" had no such problems. Zexel had to limit the Torque Bias initially on the GM 7.625" diffs as running high Bias ratios would cause excessive loading on the too small components. Eventually I had to switch to an Eaton style plate Posi with carbon clutches to handle the Torque and sticky tires when Autocrossing and Hillclimbing. I was only getting about a season and a half out of the Torsens. Zexel actually considered that very good, as some of the competition was only getting 6 months out of them . It was a DD as well. Handling with the Posi wasnever as good as with the Torsen, but I just couldn't afford replacing the diffs all the time. Edited February 29, 2016 by Chickenman Quote Link to comment Share on other sites More sharing options...
CableSrv Posted February 29, 2016 Author Share Posted February 29, 2016 OMG this is some stupid shit. You guy's won't even guess what the problem is.. and I found it. I will be uploading a video so you can see and giggle about it. So jacked up the car and double checked all my bolts tightness and to see if something was loose. Nothing could be found out of wack. Tested rolling each side of the wheel to make sure no excessive wiggle or play or noise. None! checked to make sure driveshaft operates both wheels at same time and it does... so jacked up the driver side rear wheel to see the axle at normal rest... and that's when I found it.. The inner stub is bolted to a 930cv housing using huge allen bolts. Datsun uses the same A arm for both sides just flipped. One side has a plate that is higher raised than the other side... Can you guess what side the main backing plate is on the driver side? it's at the top which happens to impact the allen bolts. The driver side allen bolts are tapping the a arm and leaving a worn down outter edge. Since I replaced my springs with Vogtland springs I still get some squat on hard takeoffs. The bigger the squat... the more those bolts hit and sound like a grind. I either need to grind the bolts down... or grind the A-arm in that area so the bolts don't hit. Quote Link to comment Share on other sites More sharing options...
CableSrv Posted February 29, 2016 Author Share Posted February 29, 2016 (edited) https://www.youtube.com/watch?v=J5vaZRz_Bn4 It explains the noise of what I'm seeing. Edited February 29, 2016 by CableSrv Quote Link to comment Share on other sites More sharing options...
Wizzurp Posted February 29, 2016 Share Posted February 29, 2016 Hahahaha, awesome! Quote Link to comment Share on other sites More sharing options...
CableSrv Posted February 29, 2016 Author Share Posted February 29, 2016 I'm just not sure I like the idea of grinding down the outter edge of my bolts... or if I should grind down the top ledge of the A-Arm so that it won't impact... Quote Link to comment Share on other sites More sharing options...
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