Twin Supercharged Miata Build (56K Beware)
07-11-2008, 02:14 AM
#43
0.5 BAR
Join Date: Mar 2005
Posts: 184
Re: Twin Supercharged Miata Build (56K Beware)
with a properly built twin scroll manifold and turbo you could have your cake and eat it too, in a sense. but I realize your wanting to try something different and I applaud you for doing so. i'm actually interested in how it turns out honestly. I how ever would only try one first and see how that turns out. I'm not sure how your going to run twin throttle bodys, or if your going to run the vam blow through or megasquirt
2" primaries wow Id figure 1.75" with a 2.75-3" collector. can you fit 2" primaries in there? I think 2" is going to hurt you a little though. I installed a jackson racing sc on a h22 and he went from a 1 5/8's pri. 2.5" coll. header to a 1.75" pri, 3" coll header with 3" exhaust and I think that was about perfect. and that was on a 2.2L honda with excellent head flow. just remember when your building this that detonation kills engines and massive cylinder pressures can cause detonation instantly. with 2L worth of blowers on a 1.8L if you ever lug the engine I think your going to hurt something. thats honestly like putting a 112 CI blower of a 03 cobra( which was intended for a 4.6L v
on your engine. the jackson racing blower is 45 CI and works well so if your put a 1L blower(61.5 CI) I think you'll be doing ok, not to mention the twin screw is more efficient than the jackson's eaton blower. so my vote is try 1 first. 
p.s. make sure you set up a couple idler pulles close together to get some good belt wrap, to try and keep it from slipping.
2" primaries wow Id figure 1.75" with a 2.75-3" collector. can you fit 2" primaries in there? I think 2" is going to hurt you a little though. I installed a jackson racing sc on a h22 and he went from a 1 5/8's pri. 2.5" coll. header to a 1.75" pri, 3" coll header with 3" exhaust and I think that was about perfect. and that was on a 2.2L honda with excellent head flow. just remember when your building this that detonation kills engines and massive cylinder pressures can cause detonation instantly. with 2L worth of blowers on a 1.8L if you ever lug the engine I think your going to hurt something. thats honestly like putting a 112 CI blower of a 03 cobra( which was intended for a 4.6L v on your engine. the jackson racing blower is 45 CI and works well so if your put a 1L blower(61.5 CI) I think you'll be doing ok, not to mention the twin screw is more efficient than the jackson's eaton blower. so my vote is try 1 first. p.s. make sure you set up a couple idler pulles close together to get some good belt wrap, to try and keep it from slipping.
07-11-2008, 02:18 AM
#44
0.0 BAR
Join Date: Nov 2006
Posts: 0
Re: Twin Supercharged Miata Build (56K Beware)
Originally Posted by patsmx5
In short it seems some are lacking in reading comprehension and fundamental physics.
I don't want a small turbo, or any turbo. Never said I did. BP series engines don't turn 8500 my friend. The cylinder head does not suport high RPM flow. The engine is already undersquare. Oil pump gears break from harmonics and crank flex at high RPMs. Torque loading and shock loads are what break the driveline, not raw HP numbers. But I agree many people suggest 250whp is the upper limit of "safe" with some mechanical empathy. This topic is clearly debatable though.
I don't want a small turbo, or any turbo. Never said I did. BP series engines don't turn 8500 my friend. The cylinder head does not suport high RPM flow. The engine is already undersquare. Oil pump gears break from harmonics and crank flex at high RPMs. Torque loading and shock loads are what break the driveline, not raw HP numbers. But I agree many people suggest 250whp is the upper limit of "safe" with some mechanical empathy. This topic is clearly debatable though.
Overly complicated for such a low output engine, but if you really want that extra 1000-2000rpm of powerband it would be much more efficient than this clusterfuck setup you're working on. As well as what you were getting at about not having as much parasitic draw with two superchargers. I mean I understand what you're getting at, what with a higher volume pump (or multiple) being able to do the same work at a lower rpm, but you're still adding drag.
Honestly it's sweet to see something like this being built, but to watch someone **** away an argument about how it fulfills exactly what they want from the vehicle and we are simply missing the point is just ludicrous.
Superchargers are for when you need power and nothing else will fit because of chassis constraints, you have none of those.
But yes, those older BP's had issues with harmonic resonance, the newer oil pumps are GTG though, as well as the newer cranks, which are spun in the same fashion as the old eccentric shafts (before they made this extra hollow ---- in the renesis motors), there is also some fancy coating on the Mazdaspeed pistons, which you can occasionally find in a salvage yard around here if you look hard enough, I don't know about where you live.
Good luck with your carrier bearing as well + the differential carrier.
07-11-2008, 03:12 AM
#45
3.0 BAR
Join Date: May 2005
Posts: 1,811
Re: Twin Supercharged Miata Build (56K Beware)
blah ------- blah blah blah bitch the seat off my nads knows more than you do. don't let the niceness of my words fool you.
your trasmission will not hold 300whp. period. 250whp it will hold; for a reasonable amount of time. so reasonably, you're a god damn moron.
your valvetrain will not floa and fly apart at 8500rpm. and yes, with a turbo the powerbad will get up there.
i bet if you put your hairy *** cheeks in the mouth of your blowers. your fine grit will port those heads out real nice!
your trasmission will not hold 300whp. period. 250whp it will hold; for a reasonable amount of time. so reasonably, you're a god damn moron.
your valvetrain will not floa and fly apart at 8500rpm. and yes, with a turbo the powerbad will get up there.
i bet if you put your hairy *** cheeks in the mouth of your blowers. your fine grit will port those heads out real nice!
07-11-2008, 12:34 PM
#46
0.0 BAR
Thread Starter
Join Date: Apr 2008
Posts: 0
Re: Twin Supercharged Miata Build (56K Beware)
Yeah I know the valvetrain is ok at higher RPMs. Never said it was not. (do you think I did? WTF?) I have datalogs of my motor at 7800-7900 and there was no valve float. However the head can't flow the air at those RPMs and it's not making much power. Add to that these motors tend to break oil pump gears above 7500 boosted. Basically mazda put sintered steel oil pump gears and crank flex will cause them to shatter.
The transmission stuff is debatable, as some people break them at 200whp in a week and some have pushed 300+ whp for years without trans problems. Hence my explanation of mechanical empathy to reduce torque loading and shock loads were more important than raw HP numbers.
Toyrsrme, if you're smart than give your opinion on something and support it with something other than "blah ------- blah", "period" ,or "you're a god damn moron". I can assure you I'm not the moron.
And I'm not sure about your statement "Superchargers are for when you need power and nothing else will fit because of chassis constraints, you have none of those." Ok I don't agree with it is more like it. They have their place and so do turbo's. But honestly I didn't want a huge turbo vs. supercharger debate in this thread. I know HMT is partial to turbo's though.
The setup will be two SC's running in parallel. The outlets of both will join into one 2.5" pipe. The throttle body will be bolted to the intake manifold and the SC's will run unthrottled. There is a bypass valve installed on the SC's' so I can turn boost on and off.
The transmission stuff is debatable, as some people break them at 200whp in a week and some have pushed 300+ whp for years without trans problems. Hence my explanation of mechanical empathy to reduce torque loading and shock loads were more important than raw HP numbers.
Toyrsrme, if you're smart than give your opinion on something and support it with something other than "blah ------- blah", "period" ,or "you're a god damn moron". I can assure you I'm not the moron.
And I'm not sure about your statement "Superchargers are for when you need power and nothing else will fit because of chassis constraints, you have none of those." Ok I don't agree with it is more like it. They have their place and so do turbo's. But honestly I didn't want a huge turbo vs. supercharger debate in this thread. I know HMT is partial to turbo's though.
The setup will be two SC's running in parallel. The outlets of both will join into one 2.5" pipe. The throttle body will be bolted to the intake manifold and the SC's will run unthrottled. There is a bypass valve installed on the SC's' so I can turn boost on and off.
07-11-2008, 01:30 PM
#47
0.0 BAR
Join Date: Jun 2003
Posts: 0
Re: Twin Supercharged Miata Build (56K Beware)
People are for getting the point of hmt. Its is to boost a car is cheap as possible. So far it is cheap and its a diy. To every one that is talking ----, lets see what you can do with the same budget; and no I am not talking about your jy/ cdm dirty D!!!
07-12-2008, 03:36 AM
#50
1.5 BAR
Join Date: Oct 2005
Posts: 1,490
Re: Twin Supercharged Miata Build (56K Beware)
hmm i never like supercharges or they are inefficient but i think this is gangster set up just by looking at the sexy supercharger brackets then the custom ignition timming wheel weldin seXy! 
and then the IM is going to be steel butt welds 90* ect sexy like a HMT styl mani i like it keep it up man post some pics of the mani progress!! it might not be efficient as instant boost centrifugal clutch driven supercharger that gets cut out of the system and the turbos take over for top end power but i think its gangster cuz this is HMT and we are the DIY custom community
and then the IM is going to be steel butt welds 90* ect sexy like a HMT styl mani i like it keep it up man post some pics of the mani progress!! it might not be efficient as instant boost centrifugal clutch driven supercharger that gets cut out of the system and the turbos take over for top end power but i think its gangster cuz this is HMT and we are the DIY custom community
