I was wondering how long does it take for you sts guys to spool up and what type of turbo you would be running

 

Before you get the barrage of sunshine, allow me to suggest that as you sift through feedback, you take notice in the comments from those who are installers and have installed, tuned, and dyno'd a variety of turbo set-ups, not just STS... also, the feedback from members who have driven in more than one turbo set-up, not just an STS.

To be fair, I'd, PESRONALLY, rather deal with some spool problem of an STS, IF there is to be agreed that there is some, than the peak boost at redline of our F-Body blowers. It's low price is also another advantage that favors it... My $0.02.

 

Its just a question and wondering about the sts nothing against anyone else just want some numbers...

 

Mine is not true STS but it is a rear mount with a MP t-61 tith a .84 turbine. Boost starts around 2600-2800 and is full 7 psi by 3500. I plan on putting a t-70 compressor housing on when I go to a custom turbo cam. Now the motor is stock plus intercooler, 42# injectors, and tune. In 6th gear at 1800 rpm I make about 2 lbs boost, when the pedal is floored. Stock 3.42 gears. I would also like to know what rpm people are getting spooled with the .68 a/r and the .96 a.r??

 

Mine is a True STS... 67 trim.. fully spooled about 3000-3200 or so (9psi)

 

2500 R.P.M On my ls6 full boost by 3,500 R.P.M my car was a freak could not understand it i guess it was in the tune and i had a 10 pound fly wheel and stock 3.42 running 8.5 psi just cant 1/4 it for **** i heard cam selections is a major player also

 

And this system is going through a fmic!!

 

remember those have a smaller AR which will choke sooner.
everything being equal about 1000rpm slower then traditional mount from the dyno graphs i have seen.

 

at WOT I'll start boost at 2200 and be at 5psi around 2500-2600. I've got the 67 w/ .81ar

 

When we mention "fully spooled by" what gear is everyone talking about?

 

So it would be safe to say that on a gt35 mm turbo at 88 .a/r that if I put a 3500 stall I would be fine?

 

We are seeing full boost at 3200rpms with a GT67 on a 2002 WS6 TA. No FMIC

 

Gearing wise I don't make full boost until the very end of 1st so 2nd would be the first gear that really utilizes 5psi.

 

Which setup are you using on your car? Because I only get about 1 maybe 2# at first and then I make utilize boost in second. Are you a4 or m6?

 

Not sure what you're asking here, but people seem to be answering a different question, but maybe that is really what you wanted to know.

You asked how long it takes to spool. This evidently would be time based, so it therefore would not be referring to the point in the rpms where boost is made, as this isn't time based.

Spool time would be LAG, which all turbocharged cars suffer from, unless running an Anti-lag System (ALS). LAG occurs after a stall period. This is when the throttle plate on the TB is closed, the exhaust gas velocity reduces stalling the turbine, combine this with the trapped high pressure air beteen the turbocharger and the TB it causes the turbine to stall. When you re-open the throttle plate, the exhaust gas flow will increase, but there will be a momentary LAG before boost is produced, this is becuase a turbocharger has to spin at a very high rpm to produce boost. A BOV or dump valve releases the trapped air pressure air, helping to minimise the stall, but exhaust gas flow is the primary culprit.

Remember ALL turbocharged engines suffer from this. Good location and well matched turbo's mean you should be able to reduce LAG to a minimum, but it will still be present.

I don't have any times for LAG, but when I spoke to an STS agent about LAG they would always sidestep the question, that combined with other comments I have read and just plain physics means I would not entertain a rear mount setup unless the car is soley for dyno numbers and straight line drag racing, if you like driving road courses it is far from ideal.

LAG can and will occur at any point within the operation boost range of the turbo. So even though it may be able to produce boost at 2500rpm and max boost by 3000rpm. If you lift off the throttle at 5200rpm for a second (cornering) and then reapply the throttle you will have LAG even though the rpm's may not have dropped below 4500rpm.

If you want the best throttle response you'll want twin turbo's mounted where they should be in the engine bay. Twins allow you to run smaller turbo's so in theory they should require less exhaust gas flow to produce boost, this means the LAG period would be reduced. Although I believe (not sure for certain) that some of the fastest and most powerful turbo cars usually use a large single turbo as it is more efficent.

-Positive Displacement supercharger offers the best throttle response and no lag.
-Centrifugal supercharger offers minimal lag. But it does contain some, again due to the high rpm's that the blower runs at to produce boost. However low end torque is comparatively poor.
-Front mount turbo. Most efficent and will produce the most power. A well sorted setup should offer good driveability but LAG will be present.
-Rear mount turbo will still be more efficent than a supercharger and thus produce more power but LAG and throttle response will be worse than any of the other options.

For straight line use probably yes. But remember without load on the engine the turbo will not be producing boost. If you rev the car in neutral the boost gage should not move.

Just my 2 pennies worth.

 

I'm running a stock 2001 M6 at 5psi. In first I usualy shift right at the turbo makes 4 to 5 psi at 5800 to 6000 rpms. I have at times seen only 3psi on hot days in the summer. I'm also still running the stock exhaust piping and cats.

 

I have a 2003 Z06 in which I installed one of the first prototype STS twin kits.

I can tell you this, the car pulls like crazy, and when I shift fast, there is a slight delay (lag), but it is not bad at all in my opinion because it helps keep the car under control (not spinning the tires as easily).

I have nothing to compare it to since I never had a turbo car before, but it is certainly not a problem. I think this setup might be great on a road course (As well as drag racing)

Tommy

 

1. you should be asking how soon you get any boost, not full boost, as once you get into positive pressure, you'll get to full boost _very_ quickly.
2. getting to positive pressure is important. it signifies how well your exhaust is matched to the size of the turbine, how well it's tuned down low to generate all the extra exhaust flow to get the turbo going, etc.
remember torque comes from compression, and compression comes from how much air you cram in there. at low rpm you don't have the hp to generate airflow, so you gotta do it through timing and intake/cam design

 

Guys on here w/ the STS setup, does the amount of vacuum line have anything to do w/ spooling (or how quickly it spools?) Let me explain. Like I said I don't produce much boost through first (ever) and I'm wondering if (because of the way I positioned the boost controller and the solenoid) the excessive vacuum line isn't causing some sort of reduced pressure or should I look at something more common line a vacuum leak or an exhaust leak? If this is confusing you please tell me I'll try to repost my question more clearly.

 

If you talking about the waste gate refrence vac line then yes the shorter the better.