Ironfreak

I have been on the fence about boosting my 5.3l bmw. I'm building this car to turn, more autox/drift oriented setup. I was going to mimic one of Denmah's setups but the more I watch his videos I'm afraid that it's complete overkill.

I would like to have around 400-500hp at the wheels at my disposal.......I just don't want to spike straight to that number.

Are there any progressive boost controllers out there that I could use that would be either stand alone or programmed through Hp tuner? I'd like to have more of a linear curve on my powerband. I'm guessing that I could help this with a different turbo then say the on3 76 or the gt45. I know that he said the combination of the smaller hotside helped for earlier boost build but I'm not sure if that's what I want if it's going to peg out instantly. This will be my first boosted LS motor so some of this is pretty new to me, maybe what I'm asking really isn't possible.

Any input would be greatly appreciated.

Ironfreak

I have looked at the eboost2 and ams-500, just curious if there are any other options out there.

LS1x2

iTrader: (11)

The eboost2 is a good controller that does what the manual says. You might need to read it 10x to fully understand though. It will let you map boost vs rpm.

Seems like a centrigual blower is what you want though.

edwardzracing

iTrader: (59)

Problem solved:

http://shop.huronspeedproducts.com/T...ller-TSEB2.htm

I can't even begin to describe how awesome this thing is... and I don't even have one. I've seen them in action and I wish my budget allowed for one, but maybe someday soon. Read up on them or do a search on ls1tech for more info, and I think you'll be thoroughly impressed.

stevieturbo

For a wide range of control options. Boost vs speed, gear, rpm, etc etc

http://www.plex-tuning.com/products/...ost-controller

http://blog.amsperformance.com/2013/...n-distributor/


However....with such a low power target, you'll be running some fairly low boost pressures to start with which will limit how much you can control it.

T76s10

iTrader: (6)

why do you want a linear power curve? whats wrong with making instant boost?

Ironfreak

The car isnt for straight line racing, i want to be able to run through a course and not have to worry about spiking and spinning out. Maybe if I just keep the boost lower like he mentioned above it won't be an issue.

hodge9386

iTrader: (5)

if your only wanting 400-500 hp just do heads and cam

DEFYANT

I agree, a Turbo or Blower is a waste for only 4-500hp.

skinnies

iTrader: (33)

holley hp efi, run it boost vs mph on front wheel speed

HexenLord

A very small single would get you 500 HP on a stock motor and would produce instant torque. As long as your waste gate is up to the task of keeping boost steady, you could hit 8-11 PSI almost instantly, and as long as you keep it steady, your torque curve would look like an inflated NA torque curve.

Production cars do this with turbos. Size a small turbo with a very modest power goal, and get almost instantaneous boost. My SRT4 on a stock turbo with bolt-ons and a ecu reflash would hit 14 PSI at 2000 RPM. The turbo was still able to push it up past 300whp/350wtq, which is more than enough for a 2900 lb front wheel drive car.

The guys that say nothing smaller than a 70mm turbo on a 5.3 have nothing more than max power and quarter miles on the mind.

Ironfreak

Thank for the reply! I actually have a smaller turbo I was thinking about trying. It's a Garrett TP38. These are the specs:

STOCK GARRETT TP38
Compressor wheel inducer diameter: 59.87 mm (60 mm)
Compressor wheel exducer diameter: 80 mm
Compressor housing A/R: 1.10
Turbine wheel inducer diameter: 76.2 mm
Turbine wheel exducer diameter: 69.84 mm (70 mm)
Turbine housing A/R: 1.15

Figure it might be good for about 500hp max on my motor.

HexenLord

That's a pretty small turbo, but a good starting point. For autocross you'll want nothing larger than a 66mm. Some turbos spool a lot faster than. Other for a given size. You can get away with a 66mm pretty easy if its billet ball bearing. It will spin up very quickly with a proper sized camshaft. Its all about achieving a balance.

Like I said, what you already have is a great starting point. Are you going to beat the 76mm guys in a straight line? No. But are you going to out torque the centrifugal supercharger guys? Yes. Start a basic setup with what you have. Once its running you can do adjustments. Better cam, free flowing exhaust, more timing, etc. If you're turbo still isn't quite to your goals, switch it out for something different. Chances are with the work you've already done to max out your previous turbo, those chances will apply to your new one as well.

Its still very possible that you hit your goals with that Garrett, even though there are better options out there. Anything much smaller might cause issues, though. I've hit 400 ft-lb (at the wheels) spikes in my little 2.4 neon. After adding an open dump and porting the exhaust and turbine, and a much stiffer waste gate with electronic boost controller, the boost would rush on so fast that I could spin the in second gear from idle as fast as I glcould get the pedal to the floor.