holy ---- the sky is falling, Jd wants a K series.
01-30-2009, 04:04 PM
#31
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Join Date: Apr 2008
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Re: holy ---- the sky is falling, Jd wants a K series.
Originally Posted by Joseph Davis
Maybe, maybe not. We put more power to the ground out of stock Honduh econobox transmissions.
Follow my logical order of what the pop culture "knows" about a D-series gearbox: D-series are weak --> D-series differentials are weak --> D-series differentials are strong, but not all of the diff pins holding the spider gears are correctly hardened, so they fail. Refinements such as D-series gears are stronger than B-series due to how compact the gears themselves are eventually filter in. There are a lot more 350+ whp D-series out there than 200 whp Miata so this logical progression in popular knowledge only took 12-14 years to come about.
:/
I don't want to hear "the diff is weak" or "the rods are weak," I want to sift the wreckage with my own two hands and form an intelligent conclusion. For example, fools hammer rod bearing upper halves into the crank journal with detonation until the bearing welds itself to the crank, the unit locks up, and the rod breaks. Fools say the rods are weak and are listened to "because they've done it." I say the rod is possibly quite strong and the fools need to find another hobby - a perfect example of this is reading Honduh forum posts of a decade ago where "6 psi D-series" and "8 psi B-series" is the most you can safely run on a stock Honda engine - barely at or over 200 whp with the turbos and manifolds used at the time.... now the intelligent consensus is that D-series rods will hold 300+ and B-series 400+.
So, after laying this all on you, Pat... what do you think? Did Honda do it right and no other automaker has a clue, or is the popular consensus largely useless? I love me some Hondas... but there's a lot of excellent ---- out there that doesn't have an H or an A badge on it.
Follow my logical order of what the pop culture "knows" about a D-series gearbox: D-series are weak --> D-series differentials are weak --> D-series differentials are strong, but not all of the diff pins holding the spider gears are correctly hardened, so they fail. Refinements such as D-series gears are stronger than B-series due to how compact the gears themselves are eventually filter in. There are a lot more 350+ whp D-series out there than 200 whp Miata so this logical progression in popular knowledge only took 12-14 years to come about.
:/
I don't want to hear "the diff is weak" or "the rods are weak," I want to sift the wreckage with my own two hands and form an intelligent conclusion. For example, fools hammer rod bearing upper halves into the crank journal with detonation until the bearing welds itself to the crank, the unit locks up, and the rod breaks. Fools say the rods are weak and are listened to "because they've done it." I say the rod is possibly quite strong and the fools need to find another hobby - a perfect example of this is reading Honduh forum posts of a decade ago where "6 psi D-series" and "8 psi B-series" is the most you can safely run on a stock Honda engine - barely at or over 200 whp with the turbos and manifolds used at the time.... now the intelligent consensus is that D-series rods will hold 300+ and B-series 400+.
So, after laying this all on you, Pat... what do you think? Did Honda do it right and no other automaker has a clue, or is the popular consensus largely useless? I love me some Hondas... but there's a lot of excellent ---- out there that doesn't have an H or an A badge on it.
I think we mostly agree. In stock form, without changing the way the car is setup, a hard 3rd gear shift at 250whp will break 3rd gear eventually. A hard second gear shift w/ hop breaks the diff.
Now of course there are people who know what they're doing and fix the weak links and make the setup stronger. But a system is only as strong as its' weakest link. Mazda did not bless us with the strongest parts in the world in all areas.
Tuning is as important to engine longevity at high boost as driving technique is to drivetrain reliability. When my car was N/A, I beat on it. Hard. Now that it's boosted, I find my gear and then apply power. I'm putting less peak loads on the transmission now just from changing my driving habit. Though I haven't touched the transmission in any way, it should fine practicing mechanical empathy.
Funny you mention the connecting rods. I completely agree. I actually started running some stress-strain analysis numbers for a 85mm stroke, 132mm rod length BP 1.8 at 7K @ TDC of the exhaust stroke just to see where it's at and to compare it to the compressive load at various power levels. Need a stock rod to get my cross sectional area to get an exact number. Point is I agree that a lot of "rules" are not really set in stone. Hell, I'm one of the few that's pushing a stock BP this far. Stock was 110whp, I'm around 270, maybe more. I'd like to run more, but I can't use full boost till 3rd as is, so other things need upgrading before I apply more boost.
01-30-2009, 04:16 PM
#32
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Join Date: Apr 2008
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Re: holy ---- the sky is falling, Jd wants a K series.
Other consideration is this is a correct wheel drive vs. fail wheel drive. So when you apply a load, weight transfer puts a higher force on the rear tires. Given two identical 200whp setups, the rear wheel drive vehicle will ultimately see higher loads.
01-30-2009, 04:29 PM
#33
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Join Date: May 2006
Posts: 5,322
Re: holy ---- the sky is falling, Jd wants a K series.
I think JD was just getting at the point that he cannot trust what you've heard until he's seen it for himself, and that Honda problems were blamed on different things through out the years until someone found the true problem, and now they are capable of more since the true weak links have been found.
01-30-2009, 05:32 PM
#34
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Join Date: Feb 2003
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Re: holy ---- the sky is falling, Jd wants a K series.
Originally Posted by patsmx5
Funny you mention the connecting rods. I completely agree. I actually started running some stress-strain analysis numbers for a 85mm stroke, 132mm rod length BP 1.8 at 7K @ TDC of the exhaust stroke just to see where it's at and to compare it to the compressive load at various power levels. Need a stock rod to get my cross sectional area to get an exact number. Point is I agree that a lot of "rules" are not really set in stone. Hell, I'm one of the few that's pushing a stock BP this far. Stock was 110whp, I'm around 270, maybe more. I'd like to run more, but I can't use full boost till 3rd as is, so other things need upgrading before I apply more boost.
You can make RWD vs FWD loading comparisons and be partly correct, but Hondas still leave under more power and 60' better than Miatas without failure. It's possible to shear off the ring gear of a Honda trans when launching @ or around 300 whp (230-250 wtq) but it only happens to people who don't know how to preload and launch as I know people who leave on stock trans at 400+ whp (300+ wtq) and never break anything... I also know guys who trash multiple gearboxes from merely burning out incorrectly much less launching, just to remind you (and anyone else reading this) it's a perspective thing not a brand thing.
There are ways to ease the entry to the next gear. The rear end hop when shifting into second... uhm, I doubt any of those guys have had a shock specifically valved for the application, they just buy Brand Name shelf parts and incorrectly ASSume it's doing the job. Also, it is important to yank a lot of timing while shifting, and once in gear add it back in within a number of ms. This can be done one most of the better standalones.
FYI, good luck breaking much past 270 on stock parts without remachining. At some point the piston has to swell under all that thermal load and without enough clearance it's going to bind, or overheat and catch a ringland.
01-30-2009, 06:12 PM
#36
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Join Date: Apr 2008
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Re: holy ---- the sky is falling, Jd wants a K series.
Originally Posted by Joseph Davis
The peak tensile loading on a GSR rod @ stock 8000 rpm redline is equivalent to the peak compressive loading at 400 whp. Not that compressive loading is the same as tensile, but yah it's a ballpark measurement that others have done for other rods in the past.
You can make RWD vs FWD loading comparisons and be partly correct, but Hondas still leave under more power and 60' better than Miatas without failure. It's possible to shear off the ring gear of a Honda trans when launching @ or around 300 whp (230-250 wtq) but it only happens to people who don't know how to preload and launch as I know people who leave on stock trans at 400+ whp (300+ wtq) and never break anything... I also know guys who trash multiple gearboxes from merely burning out incorrectly much less launching, just to remind you (and anyone else reading this) it's a perspective thing not a brand thing.
There are ways to ease the entry to the next gear. The rear end hop when shifting into second... uhm, I doubt any of those guys have had a shock specifically valved for the application, they just buy Brand Name shelf parts and incorrectly ASSume it's doing the job. Also, it is important to yank a lot of timing while shifting, and once in gear add it back in within a number of ms. This can be done one most of the better standalones.
FYI, good luck breaking much past 270 on stock parts without remachining. At some point the piston has to swell under all that thermal load and without enough clearance it's going to bind, or overheat and catch a ringland.
You can make RWD vs FWD loading comparisons and be partly correct, but Hondas still leave under more power and 60' better than Miatas without failure. It's possible to shear off the ring gear of a Honda trans when launching @ or around 300 whp (230-250 wtq) but it only happens to people who don't know how to preload and launch as I know people who leave on stock trans at 400+ whp (300+ wtq) and never break anything... I also know guys who trash multiple gearboxes from merely burning out incorrectly much less launching, just to remind you (and anyone else reading this) it's a perspective thing not a brand thing.
There are ways to ease the entry to the next gear. The rear end hop when shifting into second... uhm, I doubt any of those guys have had a shock specifically valved for the application, they just buy Brand Name shelf parts and incorrectly ASSume it's doing the job. Also, it is important to yank a lot of timing while shifting, and once in gear add it back in within a number of ms. This can be done one most of the better standalones.
FYI, good luck breaking much past 270 on stock parts without remachining. At some point the piston has to swell under all that thermal load and without enough clearance it's going to bind, or overheat and catch a ringland.
MS does flat shift. I don't have it setup now that I'm turbo, but I did when I was N/A. It would cut spark and pull RPM's down to 5K, which is about where I'd land in my next gear. Engine power basically would go off and I could get the clutch engaged in my next gear and then power on when the pedal was out. Made for a surprisingly smooth shift. Need to get this hooked back up. I rewired the car for MS standalone and never hooked it backup.
01-30-2009, 07:52 PM
#37
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Join Date: Feb 2003
Posts: 0
Re: holy ---- the sky is falling, Jd wants a K series.
Originally Posted by dabeetereater
all this talk and its still gonna be a gay ugly *** miata when its done. its got to be the one of the gayest cars ever.
Originally Posted by patsmx5
Nice talking to somebody that has a clue about ----. Yeah, the BP has a compromised coolant routing from the factory in a miata and "rerouting" it to mimic the 323's layout (engine was originally designed for) fixes this. In the stock configuration, the rear most cylinder gets the least amount of coolant. The more heat the engine makes, the more the thermostat opens, the smaller the delta P is across that cylinder. FTL. I will be doing a reroute on my spare engine when I build it this summer. For now, I don't do long boosted pulls as to not overwhelm or overheat that rear cylinder that's always the first to fail. Factory clearances are pretty tight + shitty coolant routing + lots of heat = broken ring landings. Seen it countless times.
Originally Posted by patsmx5
MS does flat shift. I don't have it setup now that I'm turbo, but I did when I was N/A. It would cut spark and pull RPM's down to 5K, which is about where I'd land in my next gear. Engine power basically would go off and I could get the clutch engaged in my next gear and then power on when the pedal was out. Made for a surprisingly smooth shift. Need to get this hooked back up. I rewired the car for MS standalone and never hooked it backup.
01-30-2009, 08:15 PM
#38
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Join Date: Apr 2008
Posts: 0
Re: holy ---- the sky is falling, Jd wants a K series.
Originally Posted by Joseph Davis
Agreed, but it's a big step down from the flaming homosexuality that bear the stigmatas known as K-series, or VW. Don't you have a n00b intro thread to make, complete with - and I can not stress this enough - **** that heterosexual men find interesting?
Yeah, not being able to cool the engine is a factor, but only on medium power rides. If you make enough power *in a drag only environment where the engine has time to cool between passes* then the pass is over before there is enough time for heat to build up. Also consider internal cooling, I'm not a big fan of water/alcohol injection for complexity reasons and I normally recommend skipping right to E85.
That can help, but there are also ignition retards that can be set up based on when the gas is depressed, clutch pedal is released, or a gear is changed (identified by ratio between VSS and rpm). That retard decays over 50-500 milliseconds, so it's effect on actual power production and transfer to the ground is negligible, but it does help with jolting the drivetrain. Nice thing about MS is if it doesn't currently have that sort of feature it shouldn't be hard to find a guy who can script it in for you.
Yeah, not being able to cool the engine is a factor, but only on medium power rides. If you make enough power *in a drag only environment where the engine has time to cool between passes* then the pass is over before there is enough time for heat to build up. Also consider internal cooling, I'm not a big fan of water/alcohol injection for complexity reasons and I normally recommend skipping right to E85.
That can help, but there are also ignition retards that can be set up based on when the gas is depressed, clutch pedal is released, or a gear is changed (identified by ratio between VSS and rpm). That retard decays over 50-500 milliseconds, so it's effect on actual power production and transfer to the ground is negligible, but it does help with jolting the drivetrain. Nice thing about MS is if it doesn't currently have that sort of feature it shouldn't be hard to find a guy who can script it in for you.
I will be putting a nice fail-safe WI setup on here. Another guy on miataturbo.net has a badass fail-safe setup I'm gonna copy. His setup runs on wastegate pressure and a conservative timing map. Then, once he gets into a few PSI, a hobbs swtich closes, turning on the pump and power heads for a chain of safety switches, including a pressure sensor right next to the WI nozzle, water level sensors, etc. Once all the safety stuff clears, a N/O solenoid is energized, shuting the wastegate off from manifold pressure and his EBC comes online, and simultaneously MS table swtiches to his WI timing and fuel map.
WI is not for everyone. But it has its advantages. Just takes a solid install and a bit of maintenance. Nothing extreme.
01-30-2009, 10:02 PM
#39
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Join Date: Feb 2003
Posts: 0
Re: holy ---- the sky is falling, Jd wants a K series.
How does the KS stuff work on MS? Done "properly" it's DSP-based, but I know the AEM guys just look at it based off the volume of noise coming off of it and claim it works well.
