stegmire rebuilds them for cheap

 

Hmmm, now you got me thinking. Do they offer a better set of rotors?

 

your not taking into consideration parasitic loss. To make just 12.5 PSI our blower draws over 30HP, and thats an efficient 12.5PSI. NOw if your running 20 PSI that has half the efficiency then your looking at well over 60-70HP to turn the blower. And no heads and cams wont make the charger not be a heat pump anymore. There are more reasons than compression that cause the heat of the blower. The biggest ones are friction and heatsoak from the engine. The compression heat can easily be fixed with better aftercooling or meth injection. That one isnt the problem. The problem comes when your spinning a charger at over 20,000 RPMS it creates alot of heat friction. Along with the fact that the charger isnt designed to operate at those RPMS and you will more than likely fry the bearings in a matter of weeks. Further more making that much HP in the engine creates alot of heat in the engine, heat that easily transfers to the blower.

So no, realistically the most our blowers will support is 300HP on a stock engine. The CFM they put might be able to support more hp, but the blower cant. It becomes far to ineficient. Yes you can do alot of engine work and possibly squeeze an extra 100 HP out of it, but why waste the money?

 

I don't think a better set, but I think they rebuild them ported and polished with ceramic bearings. Don't quote me on that tho.
I did the math, kinda. It does actually support 490hp but the problem is, the head and rest of the engine doesn't. You would have to rev to about 19,000 rpm to achieve those numbers. Even the race version of GM's 1000+ head couldn't flow like that, it would have to be made up for in boost, which can't happen according to the M62's flow chart.

Sorry about the thread jack. BTW I'm finishing my build using the stock blower and a 2.8 pulley with hks evo spec 272 cams, neutral balance shafts, upgraded valve springs and forged pistons. If you can wait till next week I should have a video and a good comparison of the car vs. a bunch of different LSJs.

 

I think if your end goal is 500HP or so then the max you would really want to go on a turbo is gonna be a Garrett GT3076R. Nice thing about the GT3076 is that you can dial in the boost for the level you want and it gives you room to grow once yur internals are done.

Best Case USE:

Turbo Efficiency is 72%
Horsepower 310 - 525
Displacement 2.0L - 3.0L

 

^^^I agree, the 3076 would be a great choice for an LSJ turbo swap.

 

There is a custom turbo kit for the 2.2 Cobalt from ATP Turbo that they speced out using the Disco Potato (GT2860RS) as a mild application turbo unit.








So on the lower compression LSJ I really would think that GT3076 is going to be the best bet like I said before.

 

^^^ +rep for good info

BTW, who gave me rep? I'll give back.

 

..

 

How about a T3/T4 60 trim like this? http://www.agpturbo.com/product.php?...cat=265&page=1

 

I think the GT3576 is to much Turbo for what you want, it will be over 4000rpm just to get full boost, which means lots of lag. A properly choosen turbo with the right compressor trim will net you the power you are looking for. 500whp will require extensive internal work to be reliable. I think a GT2871 or GT2876 ball bearing turbo will net you 330-350 whp will way less lag than the GT3076. Thats just my opinion.


Crap, I thought you were mentioning the GT3576, ya the 3076 will work, more lag than the GT2871 or GT2876 though

 

you must understand why i said it.

why be limited in the future?

hell a big 16g with the right mods will net over 400 to the tire, but a gt35 will do it more effieciently.

the 35r is not to big for the motor.

say someone full tilt builds the bottom end and head.
he's stuck with the gt28. thinking, "wow, this is a waste, why did i buy this"

overbuild. leave room to grow later in life.

something you guys are failing to see is the options on exhaust housings.
this changes the whole area of the turbos spool, and power potential.

 

What about the t3/t4 styles?

 

From my experience the T3/T4 is a decent turbo but can suffer from some lag depending on the setup. The super 60's are decent and can be had very cheap...but beware of the cheap turbo!!! There are alot of remanufactured turbo's from Japan that come in with very substandard bearings and build quality and you will end up eating the turbo up in short order.


The GT series can run more money but they are really a better turbo and produce consistent results. If you want to go crazy and dont care about low down lag then look at like a 20G or a Holset HC1 or HX35. Either one of those will keep you in the 400HP range easily of built right.


This is a 2.3L Ecopower SAAB motor with a GT3076R on it making 412WHP (almost 500BHP).


GT3076R 30PSI Video

 

Your numbers seem good to me; but you're talking about maximum power, we want the compressor to be living in it's happy place making the same numbers.

 

To get a good low lag time out of a T3/T4 what would I need for trim? New to turbos.

 

Just go with a "Disco Potato" gt2871r good to 325-350

 

500hp LSJ using the m62, I would love to see that, and I wonder why we will never see that.

 

I don't want only 325-350, I want that for now and I don't want to end up having to buy a difference TC once I upgrade the rods and pistons, etc. What would a T3/T4 spool at? I'm looking to spend $1000 or under on the TC alone.

 

potato disc is the gt2860 and its good to 360 and gt2871r can be good to 460 according to Garrett. I doubt that but if you wanna make 400+whp I would go with something like a gt3071r, but realize that there will be lag.

 

Check out the Tubonetics T3/T04E at slowboyracing.com PpAzZ1101 just bought one with a stage 3 wheel and .48a/r housing for his 2.4. Pretty good price imo. They have other Tubonetics turbos with good prices as well. Their store is about 2 hours north of where I live and they are a reputable business around here.

Turbonetics also has a great sizing chart if you aren't real good with compressor maps somewhere on their site. I'll see if I can find it.

Also, for comparison, the Holset that djt81185 put on his redline is comparable to a Turbonetics T4 60-1. Fairly laggy until 3.5K but pulls like a freight train after that. Engine work is almost required when you run into a turbo that large, so use that turbo as a reference point for the largest you can really strap onto this thing and still be streetable.

 

Has anyone figuered out the flow numbers for the LSJ yet? we should figure them out at 5psi 10psi 15psi and 20psi and then we can plot them on different compressor maps and see what will work best for the HP goals everyone has.

herea are some good links on how to figure out flow numbers.
http://forums.bimmerforums.com/forum...d.php?t=258035
http://www.turbobygarrett.com/turbob...o_tech103.html
http://www.rangerpowersports.com/tech/?p=132

 

Yeah, that would be great. I can't figure it out.

On a side note, I've been talking with AGP Turbochargers and they are recommending me the T3/T4.

Sorry, I meant ATP Turbo

 

Yes in an ideal situation you will get 460 but due to the stock cams and head I highly doubt that you will achive 460hp.

 

I agree. On Eaton's website it says the M62 was designed for engines with a displacement of 2.5L to 4.0L. As stated above, even GMs performance head will not open up flow enough to utilize all of the potential CFM. So technically at stock displacement our engine is NOT capable of producing this amount of power. So the question would be; "Well even though the engine does not utilize X amount of flow at 2.0L of displacement at 7,000RPM, wouldn't it use it at a higher rpm as the engine will flow more air?"

The answer is yes, but you would be overspinning the supercharger so this is not an option. "Well couldn't we increase the pulley size to keep from overspinning the supercharger?" Yes you could do this but then you are still setting a limit on your potential power creation.

So the turbocharger solves this problem. Not only does it have a much higher adiabatic efficiency it is not limited (as much) by the engine speed as it is not belt driven. You also do not have the losses created by the parasitic drag of the roots blower. This means that we can utilize the CFM created by the turbo more efficiently as we can push the engine (The air pump) to RPMs high enough to increase it's consumption.

So in other words, although the Evo 9's turbo and the M62 have the same maximum CFM, we could setup our smaller engine to make more power using the turbo than the supercharger.