RB26 with a supercharger.. opinions?

[onethirtyone]

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.

[jakeoster]

I believe an N/A RB25 will make ~200hp, probably a bit under. Now I'm no expert but I would say a conservative guess for a SC would be about 60hp gain. That puts you at somewhere around 260hp. The RB25DET makes around 250hp stock. With very standard mods and a small budget you can be up to about 300hp.

 

You going to have to buy your charger, a stand alone ecu, a good tuner, all your parts to make it on/off or whatever, and fab out various things. All while making about as much hp as a stock RB25DET.

 

That's the cost per hp ratio in action.

 

 

I don't know what you do for a living but your whole plan seems kind of half baked like your just dreaming. I mean 30k on a tomei crate? 0.o We do get dreamers here and it doesn't impress us or anything.

 

If you really do have that kind of budget, go talk to RIPS. They do one off stuff like this and for 30k they could probably build you what you want.

[onethirtyone]

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.

[onethirtyone]

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.

[jakeoster]

I doubt seriously that you can feasibly slap a supercharger onto an RB25/26 thats going to make 100s of horsepower.

 

There is a difference between a 2.6L i6 and a 5.0L+ v8.

 

And yes if you "don't really do anything that gives you that much money" and you are even thinking about budgeting $50k+ on a project car you are young and dumb.

Edited January 14, 2011 by jakeoster

[onethirtyone]

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..

[LanceVance]

i want power through and through, and high amounts of horsepower.

 

http://www.race-mart.com/GM_Performance_Parts-GMP-19201990.html - GM LS9 Crate Engine!

 

Half the price of what your talking about, and a helluva' lot more reliable I'm sure. Biggest problem you'll have is not twisting your car in two. I know this is in the RB Forum, and I'm all about keeping the Z a straight six, but this is Sooooooo much more practical than mating MB parts to an RB. Thousands of man hours were spent on each of these engines, if the technology was so simple that someone with 50k could swap parts and make it work on any engine, don't you think more people would be doing it? Not to mention the tuning nightmare that thing would turn out to be...

 

I'm just saying, taking a 30K+ engine, and turning it into a Frankenstein project sounds like a serious waste of time/money/effort/good parts to me...

[onethirtyone]

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

Edited January 14, 2011 by onethirtyone

[jakeoster]

Mods please move this to the tool shed, even though its a good laugh.

 

This guy is going from twin charging, to electomagnetic clutch engaged supercharging, to tomei crates, to rips estimates, to LS9 crate engines.

 

Pointless thread.

 

Onethirtyone, no one here has done a supercharged RB before. If your serious about it then contact the guy on youtube who has done it and go from there. Then you can come back and show us all up when you have a 1000bhp supercharged RB26 built by RIPS with fully forged Tomei internals.

[5thgenluder]

I am also wondering why rb? You want the power of a v8 with an on off switch? May I suggest a vq35 with a twin turbo that has a low boost and high boost setting. Then u still have a Nissan motor with a bigger 3.5 liter displacement for down low power. With a turbo for the extra power. U could have a 5 psi 330hp setting and maybe a 9 psi setting for over 400hp. And the best part is it's been done before.

[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..

[kiwi303]

Torque is torque, and torque twists the frame... basic physics, doesn't matter whether the torque comes from a NA V24 ex-WW2 fighter engine, a V10 ex viper engine, a V8 ex corvette engine or a measly little 125cc ex motorbike single cylnder running 400 psi of boost to make a 1000 HP.