GTM: never too late for another SC kit
05-13-2012, 06:28 PM
#61
Thanks guys! Wish i had my car back so i can slap these on.
I agree that the BBKs look fantastic, but i'm a little bit dissapointed on the quality of the bolts they use. The finish on the bolt is coming off at some place and it looks very prone to oxidization. I've talked to the vendor i bought it from and he'll forward my concerns to stoptech tomorrow. Interestingly enough, only the front ones exhibits this. Here is a pic of the worst side. Look at the first and third bolt.
I agree that the BBKs look fantastic, but i'm a little bit dissapointed on the quality of the bolts they use. The finish on the bolt is coming off at some place and it looks very prone to oxidization. I've talked to the vendor i bought it from and he'll forward my concerns to stoptech tomorrow. Interestingly enough, only the front ones exhibits this. Here is a pic of the worst side. Look at the first and third bolt.
06-12-2012, 02:11 PM
#67
gtm jerking off
Sorry to hear about Sam and GTM jerking you around on your time frame-they have had my car for 8 months now, on what I was told, was a 30 day time frame for dropping in my new engine-HA! hasnt happened and he keeps coming up with BS answers...hope you can get yours back before you need AARP!
06-28-2012, 08:29 AM
#68
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wow, nice build, but how much boost do you plan to push since youre running 11:1 High compression? I was wanting to boost my high compression block as well but was always told it wasn't a good idea since compression was already so high. My only options would be lowest boost possible or meth injection or else it would knock 
, which doenst sound like much fun. Whats your plan to counter act this?
, which doenst sound like much fun. Whats your plan to counter act this?
06-29-2012, 02:07 PM
#69
This has been covered in other areas, but 11:1 is not that high, intact, stock is 10.3:1, not that big of a difference eh? Add in forged internals and arp hardware and you have a strong bottom end, with proper tuning and setup you can run plenty of boost. Also, unlike turbos, there are no boost spikes and the power of a supercharger is very linear and predictable. I kind of kick myself in the *** sometimes for selling my 350z and not doing a vortech 11:0 build but that is how the cookie crumbles, at least it would have been done by now, haha!!!
06-29-2012, 04:14 PM
#70
11.0 for pump gas actually is high your not going to run much boost on that compression, e85 it isnt you show you dont really know what your talking about since a vortech builds boost in relation to rpm in a similar way a turbo does. you can size the turbos to make power lower then a centrifugal though so you make power lower. your just going to have a lower number then a similarly sized turbo since the crank is eating up power.
to put it in comparision at 10.3:1 compression running 10 psi boost you have a effective compression ratio of 17:1, 11:1 with 10 psi of boost is 18.5 effective compression ratio. from the compression ratio you will see on average a 15 hp increase if you can manage to not detonate at 600 hp, ill take a slightly lower compression ratio(10.3) and 3 psi more boost personally(since this supercharger will easily handle it). the higher compression ratio is to get the max out of the units that simply cannot push anymore air so they maximize the pressure available to what it will push.
the op isnt going to come even close to maxxing this supercharger with that supercharger unless he uses e85 for a fuel.
to put it in comparision at 10.3:1 compression running 10 psi boost you have a effective compression ratio of 17:1, 11:1 with 10 psi of boost is 18.5 effective compression ratio. from the compression ratio you will see on average a 15 hp increase if you can manage to not detonate at 600 hp, ill take a slightly lower compression ratio(10.3) and 3 psi more boost personally(since this supercharger will easily handle it). the higher compression ratio is to get the max out of the units that simply cannot push anymore air so they maximize the pressure available to what it will push.
the op isnt going to come even close to maxxing this supercharger with that supercharger unless he uses e85 for a fuel.
Last edited by jerryd87; 06-29-2012 at 04:31 PM.
06-30-2012, 10:25 AM
#73
Who ever said I would have run 600hp, and yes I am well aware of the limitations of octane, I was actually more worried about over spinning the vortech more than anything. Either way, my 350z is gone and me and gabe discussed the supercharger stuff a lot in the FI and the NA forums, I think his build will be pretty productive and a lot of useable, reliable and a lot of fun power and a lot of torque, (he is stroked!) I hope to see it finished before 2013
06-30-2012, 01:34 PM
#74
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11.0 for pump gas actually is high your not going to run much boost on that compression, e85 it isnt you show you dont really know what your talking about since a vortech builds boost in relation to rpm in a similar way a turbo does. you can size the turbos to make power lower then a centrifugal though so you make power lower. your just going to have a lower number then a similarly sized turbo since the crank is eating up power.
to put it in comparision at 10.3:1 compression running 10 psi boost you have a effective compression ratio of 17:1, 11:1 with 10 psi of boost is 18.5 effective compression ratio. from the compression ratio you will see on average a 15 hp increase if you can manage to not detonate at 600 hp, ill take a slightly lower compression ratio(10.3) and 3 psi more boost personally(since this supercharger will easily handle it). the higher compression ratio is to get the max out of the units that simply cannot push anymore air so they maximize the pressure available to what it will push.
the op isnt going to come even close to maxxing this supercharger with that supercharger unless he uses e85 for a fuel.
to put it in comparision at 10.3:1 compression running 10 psi boost you have a effective compression ratio of 17:1, 11:1 with 10 psi of boost is 18.5 effective compression ratio. from the compression ratio you will see on average a 15 hp increase if you can manage to not detonate at 600 hp, ill take a slightly lower compression ratio(10.3) and 3 psi more boost personally(since this supercharger will easily handle it). the higher compression ratio is to get the max out of the units that simply cannot push anymore air so they maximize the pressure available to what it will push.
the op isnt going to come even close to maxxing this supercharger with that supercharger unless he uses e85 for a fuel.
From my understanding the actual boost level or compression level doesn't make any difference as long as the effective compression is the same. So if 10:1 engine compression with 5lbs of boost makes say 18:1 effective compression or 8:1 engine compression with say 8lbs of boost makes 18:1 they would be about the equal amount.
It seems logical but i don't know the physics behind it. I do know that a lot of high performance FI race cars run high compression engines with boost to optimize performance. Of course they have to run the appropriate level of octane and timing.
If that actually holds true in the real world the lower boost higher engine compression at the same hp level would be a faster power delivery since it would take less time to build the lower amount of boost needed.
Please inform me because I'd like to know. We run high compression on bike engines with FI but most of the engines i build are for NA. My experience with FI on the bikes is limited but i know they like high compression.
06-30-2012, 03:58 PM
#75
most of the time people simply go off static compression(the numbers i listed would be static.) because there are so many variables involved with effective. you very well can make it work, its going to take ALOT of work with the cams and cam timing(bigger cams lead to lower dynamic compression in most cases aka effective compression but not always.) this isnt something most users are going to be able to mess with, hell im not even sure of how to mess around with the dynamic compression ratio or get exact numbers from it thats high end race team stuff. a $700 tune isnt going to get it for you either unless the tuners day job is working for a race team and he already knows all the numbers. spark timing has alot to do with it as well, most cases the tuner will say "this is the spark and boost you can run on the street on this fuel."
like i said i dont even have the knowledge to manage dynamic compression ratio with cam adjustments thats why i go off the rule of thumb using static. two engines with the same effective compression at the same power level the one with the less boost WILL make that power quicker and show more power under the curve, however typically you can get more power from more boost and less compression. that mix is less efficient(your extracting less power per molecule of fuel.) however you get a bigger bang. at a certain point though your effective compression is so high that your loosing power to spark retard though and have to either lower the boost or the compression ratio, they is going to vary between engines and where dyno tuning comes into play. for a super charger like the op has i personally would have went with 9.5:1, 10:1 absolutly max for pump+meth, e85 obviously has a entirely different rule set due to lower egt for the same power and spark timing(but honestly who does that? everyone cranks the spark up to make more power from the same egt lol) lower intake air temps, and significantly higher octane rating.
the only reason i went with 8.0:1 is because i had a power level in mind that needs to be capable of being hit on multiple fuels(or rough estimate of where i wanted it.) since i have to move often due to the army some places may only have 91, some may have as much as 94, and even others will have e85. like i said i personally would have went 9.5:1 unless he has e85 available regularly which im not sure if he does or not. that or he tunes himself and messes with the cams alot to adjust the dynamic compression, but thinking myself with no experience in it just on how a engine works i imagine this will require more overlap, which is also going to affect power output, also remember jeff bikes run a much higher rpm, which rpm has a vast affect on dynamic compression ratio as well.
like i said i dont even have the knowledge to manage dynamic compression ratio with cam adjustments thats why i go off the rule of thumb using static. two engines with the same effective compression at the same power level the one with the less boost WILL make that power quicker and show more power under the curve, however typically you can get more power from more boost and less compression. that mix is less efficient(your extracting less power per molecule of fuel.) however you get a bigger bang. at a certain point though your effective compression is so high that your loosing power to spark retard though and have to either lower the boost or the compression ratio, they is going to vary between engines and where dyno tuning comes into play. for a super charger like the op has i personally would have went with 9.5:1, 10:1 absolutly max for pump+meth, e85 obviously has a entirely different rule set due to lower egt for the same power and spark timing(but honestly who does that? everyone cranks the spark up to make more power from the same egt lol) lower intake air temps, and significantly higher octane rating.
the only reason i went with 8.0:1 is because i had a power level in mind that needs to be capable of being hit on multiple fuels(or rough estimate of where i wanted it.) since i have to move often due to the army some places may only have 91, some may have as much as 94, and even others will have e85. like i said i personally would have went 9.5:1 unless he has e85 available regularly which im not sure if he does or not. that or he tunes himself and messes with the cams alot to adjust the dynamic compression, but thinking myself with no experience in it just on how a engine works i imagine this will require more overlap, which is also going to affect power output, also remember jeff bikes run a much higher rpm, which rpm has a vast affect on dynamic compression ratio as well.
06-30-2012, 05:33 PM
#76
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two engines with the same effective compression at the same power level the one with the less boost WILL make that power quicker and show more power under the curve, however typically you can get more power from more boost and less compression. that mix is less efficient(your extracting less power per molecule of fuel.) however you get a bigger bang.
