MrStabby
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Posts posted by MrStabby
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That's porn, but the blue should be darker.
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DBA have form with this for quite a while http://www.sau.com.au/forums/topic/186532-are-you-cracking-dba-rotors/
I spoke with them at the SAU NSW tech night, and they indicated that the metallurgy is strictly specified to give the right balance (for them) of a number of properties. To oversimplfy, you could consider the composition to be either long wear life (hard & brittle) selection, or a short life (soft & tough). IMO DBAs are too far down the hard/brittle end of the spectrum for track use and they shouldn't market their rotors for track.
The cheap arse RDA and D2/G4 etc rotors dont seem to have the same issue.
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At that price it will be the 10% one - kudos have made a booboo on the description. The 25% one is $605 here;
I have the 10% one and it just feels a little tighter than the stock shifter. I got it mainly because the boot was stuffed on my stock one and I was getting fumes in the cabin. Its fine, the sky wont fall in. but if you want a noticeably shorter shift you'll probably want the 25% one.
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Fark, Just spent $40 something dollars a bottle on HPR5. When's this new stuff released?
If you put R32 GTR into Penrites recommendation guide, is says that HPR 5 SAE 5W-40 is the preferred one. The new, cheaper one may be a lesser oil.
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A few things;
- BC make different coilovers with different spring rates
- Tein make different coilovers with different spring rates
- spring rate effects ride quality
- everyone has a different idea on what is too soft / just right / too hard
- the convention when you lower is to go for a higher spring rate, so you don't keep hitting the bump stops
- you may need to change a bunch of other equipment if you want to run lower AND be able to set the alignment correctly.
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To summarise the way I understand it;
- D514A are powerful and safe, D585s are powerful (guessing probably more than D514A) but can fire early if you run too much dwell, that is, over 4 ms. Firing early "can lead to major engine damage".
- Genuine coils (AC Delco or Delphi) are more powerful than generics.
I'd guess you'd want maximum dwell at maximum torque, because that's when its going to be hardest to ignite the mixture.
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judging by the power it was making it would be fair to assume dash 5 spec but with bush bearing.
Conventional wisdom is that the wheels are an older crappier design. Hence Duncan's comment about -5s coming out 15 years later.
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So I finally had a chance to change the pump and so far it has fixed my issue.
Interesting - was the old one noisy at all?
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275 is too stretchy for me, will go to 285 next round of tyre changes.
Your +20s with 275s should have the same gap to the upright as my +25s with 265s. Do you have more than 5mm gap? (And how much do tyres flex laterally on hard cornering?)
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I have 18x10.5 +25 with 265s and the tyre is really close to curved suspension upright at the front. I don't think it would fit with another 5mm offset, let alone wider tyres.
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It can boil...but people usually notice that at the track in summer. Ever changed the fluid?
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The tyre thread is as useful as a toothbrush made entirely from ants.....
You get people who have used one tyre ever giving it 8/10. How on earth can they rate if if they haven't used other tyres on the same car ins the same conditions as others? Useless thread.
At least with the tyre thread you can get some who compare two different tyres (but may be comparing old to new), and there can be some use in that. In this thread people use engine sound or oil colour or no evidence at all to say an oil is good/bad. So its pretty much just a mix of stuff they heard from somewhere, confirmation bias and cognitive dissonance.
Also, its way more important to make sure that you don't empty the sump than to choose oil X or Y, because even the cheapest oil lubricates way better than air.
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Pretty easy to measure both temp and/or pressure drops after a couple runs up the rollers.
What kit would you use to do the measurements, and how would you install it?
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How is the factory Sumitomo calliper better in quality to the Monobloc D2/ATTKD stuff, exactly?
And who cares on the relative quality anyway, if the D2/ATTKD etc stuff has been bashed up for many years by many SAUers and been found to be well up to it?
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Truly an awful effort on that one!
I must say though, that I disagree strongly on the whole "biggest volume after the turbine outlet possible" school of thought. Respected turbo people (read, dev engineers at Garrett) have stated publicly that the very best turbine dump is a conical taper expansion from the diameter of the turbine outlet up to the diameter of the required dump pipe size. Said conical expansion needing to be about 10° included angle, or somesuch small angle.
100% correct. You can see this in carbie design too. There's a short radius into the venturi, then a long, small angle cone out of the venturi. That's because the transition from large to small produces less turbulence than the transition from small to large, so you need to take more care with small to large. IIRC its 7 degrees but as you say, its impractical to go too small with the angle because it makes the cone too long.
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The air bubbles will travel to the highest point in the cooling system. The coke bottle is the escape route.
Not if there's a low point in between. Definitely make sure you get coolant out the bleeder and leave it open until there's no more bubbles. I don;t need the coke bottle with my 32 if its on flat ground.
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News said it was e10 only.
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Waste gate flap is probably hitting the split pipe
Happens all the time on those.
But he said the flapper is moving almost 90 degrees.
Maybe try disconnecting the actuator so the gate will be blown full open and go for a run (with epic lag) to see if it still creeps up the top end. If so, the its a hot side/exhaust problem.
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Also talking about cold temperature wear, I find it hard to believe it is so significant at low rpm. I remember years ago in the bobtheoilguy site that an engine builder was talking on this topic and was elaborating on the fact that when the engine is cold, tolerances are increased significantly, therefore there is an advantage for a higher oil viscosity. His theory( which he practiced for over 50 years), was that it would minimise piston slap, protect the rings and assist the bearing from mechanical wear when cold due to the fact that the oil film was much thicker and could provide a structural support film.
He recommended a 40-50 weight mineral and also mentioned that a simple sump heater to keep temp at 20 degrees would be optimal.
Film strength in a bearing is a product of viscosity and RPM, so heavy lugging at low RPM can be risky, but then the viscosity is higher because the oil is cold. Also, when the oil is cold, there can be less flow as the high pressure means that oil can be pushed pass the bypass valve to limit pressure, rather than being pushed through bearings etc. Interestingly flow at the pump does not have much effect on film strength, unless you get into starvation.
If you heat a circular rod and circular hole made from the same material, the rod OD and hole ID will change the same amount. Forged pistons can expand more with temperature than cast block, so you need to take that into account when assembling the motor. Not sure if that's still the same problem it used to be - maybe they're tweaking the alloy's coefficient of thermal expansion to be more like cast iron?
Anyone who still recommends a mineral oil these days has not kept themselves educated with how oill tech has changed. Fairly typical of older mechanics.
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I'm just not a fan that's all. don't believe there's a oil that can do it everything is a compromise.
all oils are made with there own mix so which oil are you talking about?
I'm taking the advice from a very knowledgeable oil engineer who has since passed away but I'm happy to dig his threads up and share them with you
I read that stuff of Georges you posted and it agrees with the other info i've read.
He does say "The "expensive" VI improvers are extremely shear resistant and when combined with a high quality synthetic base stock are synergistic", which was the point I was trying to make. I didn't specify "quality" oils as i should have, so there was some ambiguity. My starting point with oil is Mobil 1 since it appears to be a bang for buck winner (as long as you don't pay Australia tax).
Also, remember that oils are continually being updated as they go through certs, eg SJ->SM->SN and change manufacturing methods eg PAO to GTL. Some time back Mobil 1 0W-40 showed shear is some motors, but these days people don't seem to be seeing it. The formulation improves over time, and the VIIs will become more shear resistant.
I would follow Georges recommendations for that particular vehicle and year of recommendation, but for a different vehicle and as time moves on they will become less and less relevant.
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I'm not a fan of oils with big viscosity ranges as oils "main" job is to lubricate and
5w-60 and 10w-60 are loaded with viscosity changing polymers.
The less of these v/c polymers are in you're oil it's safe to say the better it is going to lubricate your rotating assembly when your bashing on it.
The Viscosity Index (VI) of an oil depends on the combination of base stock and v/c polymers (aka viscosity index improvers (VIIs)). Do you have any URLs that show modern low VI oils lubricate better than modern high VI oils? I haven't seen that from what i've seen/read.
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Stock. Use 5-10W40
Build. depending on tolerances 5-10w40 to 50
+1
Why did you get a 15W-60 when there's a 5W-60 available from Penrite
.Some guys like a smaller spread on the numbers based on the theory that the oil will be more shear resistant, but i think most oils are good enough now that its no longer a realistic concern.
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So I used it today. Worked great. Didn't smell that bad at all and sure took the chill off quickly.
https://www.facebook.com/eric.yamashita.96/videos/1023814724310442/?l=2465421167051501678
Would be cool to find some biodeisel for it - ex french fry oil would smell pretty good
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there's another thread http://www.sau.com.au/forums/topic/450147-r32-door-hinges-and-door-removal/ on replacing the hinges
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Rda Rotors Issue
in Suspension, braking and tyres
Posted
Dont forget to check radius rod bushes...