onethirtyone

i know that a lot of people end up putting a v6 or v8 engine in the z, and it ends up twisting the frame. and knowing me, i would do that. so i guess another question, if i had a lot of that same torque from a supercharger, but in a L6 instead of a V6, would it still want to twist my frame as much? and actually, that's a good idea. i didn't even really think about just a high/low boost setting.. i was just thinking off and on. i think i like the high/low boost thing even more.. and what's better; like you said, it's been done before..

very good point.. i think i'll definitely have to look into that engine a bit more..

why can't you put a supercharger that will do hundreds of hp if you can do a turbo that will do hundreds? it's all about airflow. and i know that's a lot, and it sounds dumb. but, in a year, the biggest part would be taken care of the engine. then it's about a 20k project. something that i'm thinking could be done in around 5 years, all said and done. does that sound so off? and i actually DID take your advice about RIPS, and emailed them. i'm in the process of trying to get an estimate. it seems you're right, and RIPS would be a better way to go than a 30K Tomei built crate engine. i do thank you for pointing me over to RIPS, i should have thought of that..

i was just looking at the twin screw supercharged RB25 that's up on youtube. http://www.youtube.com/watch?v=eHCbYgR3mBg i did the conversion, and he said he was making 335 HP. with the belts done better, could have probably done about 400. and that's a 2.1L supercharger, which would MAYBE make around 15 PSI of boost. i could easily get a larger one, and push around 20, if not more. now it really all comes down to this, i think. CAN you push that kind of boost through an engine with a 9.5:1 or 10:1 compression ratio, if you have an adequate intercooler? because if not, there's really no reason for an electromagnetic clutch, because with a low compression ratio, you'd have no power and really crappy gas mileage. i'll just put a SC on and call it good. but if you can, why not have the option of turning off the SC if you don't need it?if you're cruising, the twin screw style of supercharger looses it's efficiency DRAMATICALLY. so instead of getting crap MPG for no reason, shut that sucker off, and get the mileage of an NA engine. is that such wrong reasoning? and i'm not trying to be a smartass, i really want to know if i'm just young and dumb, and my ideas are pointless and impossible.

from what i've been looking up so far, i can actually get a few hundred HP with a supercharger, i just have to get one large enough to push that much air, just like a turbo. it's all about the size. i mean, just one site was saying using their SC and a stock engine, they were getting 800+ HP mid 90's mustangs. right around 900 HP for 2000 and up. it's really a matter of how much air can it pump out. i mean, with the stock turbo of the RB25DET, you're not going to get 600 HP. you have to get a turbo that will produce more airflow. same with a SC. with a SC that produces around 20 PSI of boost (a nice one, $5-7k), i could get 500-600 HP. i don't do anything that really gives me all that much money, but i've been saving, and i would have the money for the Tomei parts/crate engine in about a year. the reason i've been looking at those, is i'd rather over-build my engine, than under build it. those tomei RB26's can handle 1000+ HP. if it's built for over 1k, but i'm only running like 6oo through it, then there's not going to really be any issues. and then there's the ECU, which would be... let say 2k.. is that a good estimate? then yes, i would have to fabricate a bit. the mount for the SC, and however i would get the electromagnetic clutch into a SC, and let's put aside about 5k for that. i will be honest in saying i have no idea how much fabricating of parts really is. the 5k is a completely wild guess. so far, i've estimated 32k for a Tomei engine 7k for the SC 2-3k for cams 2k for the ECU up to 5k for the transmission so that's 49k for the setup. then mounts for engine and trans, which would be about $500 $49,500. then money for suspension and brakes, which will be another few thousand. so i'm estimating this whole project to be around 50k. i know it's going to take a helluva long time. but when finished, it will also be a helluva lot of fun. but, i also feel like some of my info is wrong. or maybe the setup i want to do doesn't make sense. that;'s why i'm trying to talk to you guys on the forum to work through my problems, find out what needs to be changed/eliminated, and more accurately estimate costs.. but, 50+k IS a lot of money. but i also don't really know how to get what i am looking for. like i said before, i would love something like a turbo, but there's no power in the low end with a turbo. and lag. i want power through and through, and high amounts of horsepower. and i know you can't really do that without using forced induction. and no style of supercharger (INCLUDING turbos) will have the great low end boost AND high end boost, and almost no lag, like the twin screw SC. and unless i find out that the clutch system with a SC would be completely pointless, i would like to keep that idea.

true, the larger ones do not use an electromagnetic clutch, normally. i've been trying to research more on how exactly the clutch system is installed in the MB systems, then maybe try to mimic/adapt that. i'm sure there's a way to do it, it's a matter of can i find how to do it, then once i do, would i feel that i had the ability. and it seems i was misinformed, if that's how they are. i thought the parasitic effect was more than just a couple horsepower at little/no throttle. and part of the reason i thought a clutch system would be good, especially for a twin screw type, was i remember reading they are very efficient while under boost/load, but their efficiency drops significantly when not under load, oddly enough. so i would be creating a lot more heat just cruising than actually under load. hence if i had a clutch, if i'm going for a long drive or something, just turn it off and not waste the gas and have it build up heat, losing efficiency, and then just turn it on when i need it. and from what i've seen, i could get a cheaper one for around 5k, but i was mainly looking at a Tomei built or using Tomei parts for a rebuild, and the complete engine is $31,900. if i were to do a rebuild myself, and just use Tomei parts, it would be about 28 or 29k. then the transmission would be another.. lets say 5k (i was thinking of using the RB25 trans). i've seen them for cheaper, but, i don't want to skimp on stuff, then spend more money trying to fix stuff later. then comes wiring and differential and drive shaft and stuff, which i have honestly not priced out yet. i know a supercharger can be anywhere from 2-6 or 7k, depending on size, brand, etc. if there is something i have forgotten to list for the RB, let me know, it would be greatly appreciated. the reason i don't have a car and engine yet, is i would like to completely figure out what/how i'm going to do things, price it all out, then decide if it's worth it.

yeah, the loud exhaust is definitely something to be cautious of.. my friend had a 91 jetta with a V6, with a 2.5" exhaust. and when he got into an accident, people swore he was speeding cause his exhaust was so loud.. hahaha so yeah, something to be thoughtful about.. and i definitely understand the whole parasitic thing with a SC. that's why i was thinking of a system like Mercedes Benz. an electromagnetic clutch, like on an A/C system. when it's off, it's just freewheeling. there's no resistance. it's ONLY when the SC is actually on that there's resistance. and i thought about doing just a large turbo, but that's the thing. i want something that will help give a lot of low-end, as well. because if you want a street-tuned car, you're going to want more torque. for a track car, mainly horsepower. and that's what i like about the twin screw type of supercharger, is it will give you power at both ends. cause i'm not going to lie. i wouldn't use the SC ONLY on the track. i'd use it to have a little fun on the street as well... and what is it about the turbos that give a better cost:power ratio? i just don't know.. i mean, i thought that superchargers were around the same cost as a good turbo, and the intake stuff probably as expensive as all the extra exhaust manifold stuff.. or am i wrong? is it that turbos push more air easier than Superchargers?

ok, well, first off, thanks Boosted, for just trying to shut me down and calling my idea stupid. that's not going to work. i want to talk all the way through this fail so that i can learn. otherwise, i could just walk into something later that i could have learned from this. secondly, i would really like to have ideas and plans on paper first, so that i know what i'm aiming for, and don't waste my money on like 4 different set ups. thirdly, i know it's "roots style." just like twin screw is a style of supercharger. and i figured anyone who would be able to help wouldn't need me to put "style" after "Roots Supercharger" to know what i was talking about. now, back to my actual issues.. i didn't really want to do so much a twin charging system, as something completely new. that's where my problem is/was. for my original idea, i would have had to have the wastegates operate at one level of boost, and then when i turn the SC on, have it operate at a completely different, higher level. the only thing i could come up with, is that i would have to have 2 boost sensors, and the lower one would have to be over-ridden once the SC was turned on. but i don't really know how to do that. so i've ditched that idea. so now, based on what i've read/heard today, i was thinking still do the on/off switch supercharger, like a Mercedes Benz, but on an RB25. because it would have a high enough compression ratio to still have some get-up-and-go with the SC turned off, but i think with adequate cooling via an intercooler, i could run enough boost through all RPM ranges with a twin screw "STYLE" supercharger to have a lot of fun on a track. so my biggest question right now is, can you run forced induction, with a 9.5:1 compression ratio, and still achieve high amounts of boost/power, if you had an adequate cooling system? because if not, there's really no point to an on/off supercharger, is there? then it just becomes an argument of which is better, turbos or superchargers? and that argument has been going on for decades..

so i did a little bit of research.. and it looks like the RB25DET has a fairly high compression ratio for a forced induction engine. so then with that, could i take off the turbo of an RB25DET, use a twin screw with an intercooler, and just do that? i mean, cause then with a 9.5:1 (i believe that was the DET, and the DE was 10:1) compression ratio, that wouldn't be bad at all for mileage or response, because that's as high as a lot of NA motors these days, and with a good intercooler, i could keep the air going in nice and cool, so couldn't i do that? it would have the responsiveness of an NA motor because of the high compression ratio, but the overall power of FI.. or would that not work at all? i mean, i would build the hell out of it to begin with, to make sure it could handle lots of power..

thanks for the advice, Canadianz.. my goal is definitely a smaller engine that feels like a larger displacement. to be honest, a lot of the stuff about forced induction bothers me. like boost lag, and not having much of a low end with things like turbos and the like. maybe that's because i've never really driven a car with turbos, but, i like the behavior of an NA engine a lot better. but i realize that without forced induction, i can't really get an NA engine to produce the numbers like a forced inducted one. that's why i like the idea of the twin screw SC a lot better. boost happens at a little over idle, there's not as much lag (at least i'm pretty sure, but i could be wrong), and there's not as much of a surge of power, when the boost kicks in. it behaves a lot more like an NA engine, from what i've heard. if i'm wrong, please let me know, because i don't want to spend a bunch of money on this and find out it's not at all what i was thinking. from the research i've done and what i've heard, a twin screw SC's power curve looks a hell of a lot more like an NA engine than a turboed one. and i think i'll definitely have to look at getting those two books! they sounds like they'd be very good, and right now, i'm about to have a lot of time for reading and research..

good point. and i've actually seen that pic before.. but the biggest problem with the way I wanted to do it, was the fact that on the top end, the turbos would be X HP, while the SC when on would be adding even more at the top end. then it became an issue with the wastegates operating at the right boost levels, with the "right" levels changing. the setup in the pic is probably more just for normal twin-charging.. that's my guess.. so then if it's usually just like a single giant turbo for huge numbers, how is it that some of the more extreme mustangs get crazy numbers, close to 1k? i mean, i know the shelby's use superchargers.. do they do a twin charging setup? i thought the biggest issue would just begetting a SC big enough to push that much air.. cause i also definitely planned on doing things like cams, chips, intake, exhaust, all that kind of stuff to help push a few more numbers here and there.. and like i said before, i'm pretty sure i've seen built RB25's with i think like a 10:1 compression ratio. with something like that, could i just put a SC or turbo on it and use a really good intercooler/radiator to keep it all pretty cool? cause then i would have all the low end and gas mileage of a high compression engine, but then the high end of a forced induction engine?

ok, and so with an RB25, how much power can those take? i mean, i don't plan on putting 1000 HP through it, but i'd love to have the option of 6-700 HP.. and with a good enough intercooler system, could you use a SC with higher compression ratio and still get like 600 HP or would i really have to get low compression pistons?

actually, i just looked it up, and MB uses a twin screw SC for those systems.. so couldn't i just adapt the MB system for the RB? i mean, maybe just buy a MB supercharger with the clutch system, and install it on the RB, and wire it to a switch in the car, and to the ECU? and for re-programming the ECU, could i use a MB ECU, or would i just have to try to re-program one for an RB to closely match the MB one in regards to the SC? i don't know much about ECUs, so this is where a little help would be appreciated..

why would it be a tuning nightmare? i mean, Mercedes Benz does it, but i think they use a roots SC. so the biggest issue would be a bypass system for air to get through to the engine when the SC is off. and couldn't i have a piggy-back ECU that only comes on and adds input when the SC is turned on.. i mean, wouldn't that work? or am i missing something? like i said before, my knowledge base isn't exactly extensive, so that's why i'd like opinions, and maybe a little help..

so at first, I thought it would be really cool to do an RB26DETT with a supercharger that's on a clutch, so you could drive with the SC off, and have fun with the turbos, but when you hit a track or wanted all the power, just turn the SC on. well, due to physics, current state on engine technology, and my own knowledge base (which i don't think is all that great to begin with), i don't think i'll be able to do that. i got close to figuring it out, but alas, i've ditched that one. so here's my new idea; ditch the turbos on the RB26, and use a twin screw supercharger, with an electromagnetic clutch system (like the air conditioning in a car) so that it's still an on/off thing, but without the added complexity of having turbos in there as well. i would like to this setup for a few reasons; 1) twin screw because it gives great boost for all engine ranges. 2) you could cruise around town if you wanted, without having to try and wrangle huge amounts of HP, but if you took it to the track (i intend on doing both both), you could flip on the SC and have some serious fun. 3) i also thought it would just be really different, and kind of cool.. with that being said, i would like opinions on the matter.. and FYI, i HAVE thought about doing ball-bearing turbos that spool quickly, but again, there's no on/off system, that you could really use, AND, twin screw superchargers (if i remember correctly) can begin producing boost well before even the ball-bearing turbos. thanks!