Turbo spool time

[kkmcgregor]

So I'm sure this has been asked ,and answered, before but I can't seem to find the answer. Is there a list for the general spool time for a 2.0. For example a 6262 hits at 5200. . .
Also what do you guys find the best turbo for street performance is?

 

[jeverts]

This is always a broad question. What kind of horse power are you looking to make? I don't think anyone has done a spool time chart just for the fact that there are a lot of other variables that go into turbo spool time.

 

[kkmcgregor]

Thank you and I understand that. I was asking to see if there was a general consensus for "ordinary" mods (cam exhaust manifolds). I know all of these things affect spool time but still the exhaust from a 2 liter should spool x turbo right around x rpms.

 

[MellowVR4]

I have 272 cams, 60 trim journal bearing turbo, pretty much un-tuned and mine doesn't really start doing anything past 10 psi after 4500 rpm.

 

[transparentdsm]

on SD with 3" exhaust, 2.5 ic pipe, large intercooler, evo 3 16g, FP race mani, 780 injectors, stock cams, ecmink w/ boost controller i hit 22psi by 3200 rpms at 6300 feet elevation.

your question is super vague, im not sure what your trying to do, but if your asking this for your car as an upgrade, start with a HP range and what you'll be using the car for and it will help us.

 

[EMX5636]

There are a lot of variables that can drastically affect spool. SMIM or stock intake manifold, header/manifold type, size and brand of cams, compression ratio, etc. You can probably get a window, but don't expect the same results with the same turbo, but different setup otherwise.

For example, I get low to mid 30's PSI (depending on meth or not) just under 5k RPM with a billet DBB 5857 Precision. Most 30R sized turbo's will be in this range, where most 35R sized (like the 6262) will be closer to the 5500 range. Again, your results may vary.

 

[donniekak]

I run a dsm82htz and get 30psi by 4700 rpms in 3rd gear, and get around 71lbs/min out of the turbo. By far the best street turbo I've ran. I have good power from 4300-4400 rpms all the way to the 8750 limiter.

 

[diambo4life]

As mentioned, a lot of variables can change spool even on the SAME turbo and same car! Some of my own findings. All data is rolling in third gear, straight road to attain boost threshold. Do note on most of these, the setup was not identical. My observations have been cams, intake manifold and presence of a CAI make a big difference on spool. I tried to remembber as much as I could since some of these aree from 8-12 years ago. All these were logged with a boost sensor in Link. I'm a data hoarder and log probably too much so i notice small changes easily.

2.0L, 8.3 C.R, 6 bolt. Otherwise healthy engine.
FP3065 35psi 5,000'ish, HKS 272s, stock intake (+300rpm on SMIM)
PTE6776 T4/0.68 30psi at 6,000ish, HKS 272/272, SMIM
PTEGT3582R T4/0.68 35psi at 5,000'ish BC 280s, stock IM (9.0 C.R. engine)
Holset HX40 (Mitsu housing) SMIM 35psi at 5,000'ish (Web stage 2s)
GT3076RLE (Mitsu, 520HP version) SMIM, Web stg2s 35psi at 4800'ish >>surprised me how laggy this was, had the spool of my old 35R with more than 100whp less power

 

[EfiniX]

264/264 cams, speed density, FMIC, frankenstein T3/T04 w/ 54 trim and .60ar, FP racing exhaust, and Fujitsubo 30" turbo-back. spools at 3750k. 25psi @ 4200 or so.

 

[MellowVR4]

I've been contemplating on selling my 272's and getting a set of 264's for a little quicker spool. /ubbthreads/images/graemlins/dunno.gif

 

[GSTwithPSI]

Food for thought:

"Boost threshold is the engine speed (usually measured in RPM) at which there is sufficient exhaust gas flow to generate positive manifold pressure, or boost. Turbo lag is the time delay of boost response after the throttle is opened when operating above the boost threshold engine speed."

Most of what you guys are describing identifies boost threshold, rather than turbo lag. Although the terms are almost always used interchangeably (even by some manufacturers) it's important to distinguish between the two. Giving your boost pressure at a given RPM (boost threshold) in conjunction with the amount of time it takes to get there (boost lag) is much more valuable than either value alone.

This is the entire reason I piss myself laughing when people scoff at logs being an accurate way to gauge performance. You can decipher more from a single 3rd gear pull than any dyno sheet or time slip ever printed. I can plot the time you went WOT and correlate that to the time your boost peaked and tell EXACTLY how laggy your turbo is. Sure, making 30 or 40 PSI by 4k RPM sounds great until you figure out it takes you 3 hours to make it.

BTW, I'm not knocking anyone in this thread, especially Donnie. I know you guys have some amazing setups making good boost at low RPM. If the OP want's advice, he should look at these setups with associated spool times, and follow suit with his build/turbo setup.

The next time you guys see in some thread bitching about "post a log, blah, blah, blah", now you know why.

Edit: I've also seen boost threshold defined as the point at which the turbo begins to make boost; e.g., after you go WOT the point at which the car transitions from vacuum to positive manifold pressure (boost). In this case, I suppose lag would be used to describe anything after boost threshold...Which is also why the terms are probably used interchangeably.

The point I was trying to make is, there are two critical pieces of information in regard to lag: The point at which you reach your desired boost, and how long it took you to get there.

 

[donniekak]

One of the reasons I went with a ball bearing turbo is because of the transient response. If I'm at 5,000 rpms in 3rd and go wot, my car takes off like an na big block.

Another benefit of a larger turbo is that when driving in traffic it doesn't behave like an on/off switch between 2500-4500 rpms. I can take off from a red light at part throttle like a normal person. Most of the smaller turbos don't like part throttle operation in an rpm range where they make full boost. You'll end up opening and closing the bov rapidly because the partly closed throttle plate causes a large enough difference in pressure between the charge piping and manifold to open the bov.

 

[turbowop]

Transient response is the reason I went from an FPgreen to the FP3052. Spool time between shifts felt like it was improved 90%. Huge difference between journal and ball bearing turbos in that regard.

 

[turbohf]

I have never really understood this "spool time"... but here is mine thoughts:
2.0 + fpred 25psi = slow response.
2.4 + red 25psi = faster... but want quicker
2.4 + t4/t67 ~16psi = comes on quick! 25psi is gonna need a clutch lol.

I know I'm sure I make no sense. I honestly don't look at the tach or logs. for me its all about the usable power. new setup is beast at 4k rpm. before it was like 4500 or so. new turbo does it at lower boost and does it quicker in rpm. way more fun to drive on the street already, only been 10miles.
btw really seems to me all these setups make around the same power. cams did make a power jump.

/ubbthreads/images/graemlins/dunno.gif

 

[marvinmadman]

My car holds boost when shifting. FP Red JB. No lift shift helps /ubbthreads/images/graemlins/grin.gif

 

[turbowop]

I had to use NLTS back in the day with my FPgreen to keep it spooled. That was crazy hard on the clutch though (and drivetrain)...and probably a good reason the springs ejected from two of my ACT street disks. Made for ridiculously fast shift though.

 

[ghostinthevr4]

You probably didn't have it setup correctly NLTS when set properly is easier on the clutch and the transmission. I use NLTS and anti lag all the time revving to 9000 rpm when I shift I have it drop around 6000 rpm never any issues. Once I hit the track again I'll set the shift point higher to see if it helps.

 

[turbowop]

Well back when I was using NLTS it was via a keydiver chip. There was no way to set that up. Things have changed a bit since then. /ubbthreads/images/graemlins/rofl.gif

 

[ghostinthevr4]

That makes since now I can't speak for the Keydiver chip.