Turbo or Supercharge??
#31
Here's the math - We know we can add nearly 7 psig at sea level for a total of 21.7 psia, giving a theoretical 256 whp. That's it, period. 100hp? Not going to happen without custom pistons to reduce the static compression ratio, even with water or methanol injection. You're also going to run into flow problems with the injectors if you put any real boost to it, but that's a completely different problem than just getting the necessary air in the engine to make the power you're talking about.
Nothing like what you describe will happen for $6k in parts alone. Good luck though, I'm sure you'll be telling us stories we've already heard a few times over about waiting and the shop not delivering, and the results not being what you expected...
Nothing like what you describe will happen for $6k in parts alone. Good luck though, I'm sure you'll be telling us stories we've already heard a few times over about waiting and the shop not delivering, and the results not being what you expected...
#33
you get a lot of **** on here for asking about turboing an is250... nevermind all the bashing and the "go buy another car" way of thinking. im having a turbo custom made for my is250. will add about 100hp boost. including everything (even professional installation and professional tuning) its going to cost me about $6000. what ya think?
I'm not into the "Go buy another car" way either. We all have our own preferences and needs. I like my 250 and I could certainly have bought a 350but, I preferred to have Awd because I was coming out of a 4Runner, and just wasnt ready to go back to a rear drive only car. Just my preference. If I lived somewhere where it didnt snow, things might be different. I know I gave up power for extra convienence, but it's still damn nice car.
I say If it works and is reliable, I'm all for saving up and dumping the money into my car for an extra 100hp or so. If it involves internal engine work to get there so be it. I've done this in the past on a Trans Am with a Paxton SC kit spent $4500 and I loved every minute of the 100hp improvements. If down the road a turbo kit is availible for the 250, I'll be on board.
#35
LOL I am, but I also am going to just enjoy the car now, do a few mods and just have fun too. Even if a turbo or major hp upgrade never happens for a 250, I still like the IS, and hanging out here chatting it up about these cars.
#36
Hello all,
I received a bit more information from RGM about the status of the IS250 SC kit. The attached file is just a condensed version of what was posted on their site some time ago.
I was informed that they are waiting to do a second install before completing the instruction manual etc...
Flame away.
Any SC donations can be sent to my PAYPAL account.
I received a bit more information from RGM about the status of the IS250 SC kit. The attached file is just a condensed version of what was posted on their site some time ago.
I was informed that they are waiting to do a second install before completing the instruction manual etc...
Flame away.
Any SC donations can be sent to my PAYPAL account.
#37
you get a lot of **** on here for asking about turboing an is250... nevermind all the bashing and the "go buy another car" way of thinking. im having a turbo custom made for my is250. will add about 100hp boost. including everything (even professional installation and professional tuning) its going to cost me about $6000. what ya think?
naa its not fishy i know the guys so they're giving me a pretty good (....) price. if i didnt just spend almost 1k on lawyer/ticket fee's i'd be doing it for sure.
haha oh great so im trailblazing for all the other isx50'ers who want a turbo set???? you should all give me a few hundred $'s to be the first to try it.....
haha oh great so im trailblazing for all the other isx50'ers who want a turbo set???? you should all give me a few hundred $'s to be the first to try it.....
#38
Hey, I just got a link to the RGM SC kit.
http://www.youtube.com/watch?v=-emSrKj70Fo
I guess I am some sort of RGM groupie or somthing.
Enjoy,
http://www.youtube.com/watch?v=-emSrKj70Fo
I guess I am some sort of RGM groupie or somthing.
Enjoy,
#39
Hey, I just got a link to the RGM SC kit.
http://www.youtube.com/watch?v=-emSrKj70Fo
I guess I am some sort of RGM groupie or somthing.
Enjoy,
http://www.youtube.com/watch?v=-emSrKj70Fo
I guess I am some sort of RGM groupie or somthing.
Enjoy,
Too bad they didn't do this to a 350 too.
#40
#41
No, they're starting at 6000 ft and boosting to 21 psia because the engine will handle it. The stock number at 6000 ft is very low. Adding enough boost to hit 21 psia will give a huge bump to the power.
#42
They list stock output at 153kw, which is 205hp (which is about right; Lexus says 204)
Then they list blower output at 280 kw, which is 375 hp. That's +170 actually.
Further, they state boost is 0.5 bar, or 7 psi....not 21.
And their numbers make even less sense when you look at their posted dyno chart... which shows 139 rwhp stock and 248 rwhp on boost.
That suggests a -34- percent drivetrain loss if their 375hp claim was correct.
Which is almost triple what most people observe. (well, 32% stock, 34% on boost, either way a LOT too high)
If you take their dyno chart and work backward to apply the same drivetrain loss everyone else on earth sees with a 2IS you end up with about 288 at the motor on boost... which is a gain of 83 hp, rather than the 170 they're claiming...only problem with that is doing the same with the stock rwhp number means they started with an engine that only produced 162 engine hp.
So I can't find any way to make their numbers add up no matter which set you start from.
Last edited by Kurtz; 11-10-09 at 05:16 AM.
#43
The devil is in the details on this one.
21psia I believe refers to absolute pressure instead of the relative gauge reading. 7psi+14psi = 21psia
Absolute pressures are used for drag race math from the books that I have read.
I can't really believe the 375 bhp claim either. My initial take on the numbers when the graphs were new was slightly less HP then a stock IS350 but a bit more torque.
My only guess is that it is a corrected to sea level calculation and very optimistic. Actually I personally would not want the power to be that high as it is probably way over what the IS250 drive train can support at least long term.
The wild card for me is the liquid to air IC since the few other SC kits use Air to Air. The density of the air charge is just as or more important then the gauge psi.
Additionally, comparing a NA car to a FI car and high altitude could be optimistic as well since the supercharger will make the vehicle "breath" much better even with thinner air.
I still think this kit is cool as hell however from an engineering as well as emotional standpoint.
21psia I believe refers to absolute pressure instead of the relative gauge reading. 7psi+14psi = 21psia
Absolute pressures are used for drag race math from the books that I have read.
I can't really believe the 375 bhp claim either. My initial take on the numbers when the graphs were new was slightly less HP then a stock IS350 but a bit more torque.
My only guess is that it is a corrected to sea level calculation and very optimistic. Actually I personally would not want the power to be that high as it is probably way over what the IS250 drive train can support at least long term.
The wild card for me is the liquid to air IC since the few other SC kits use Air to Air. The density of the air charge is just as or more important then the gauge psi.
Additionally, comparing a NA car to a FI car and high altitude could be optimistic as well since the supercharger will make the vehicle "breath" much better even with thinner air.
I still think this kit is cool as hell however from an engineering as well as emotional standpoint.
Last edited by Gaugster; 11-10-09 at 07:42 AM.
#44
The other item of interest in their claims is that they supposedly have a piggyback chip that will change timing, fueling, etc
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