Twinscrew and Centrifugal boost curve on same graph

[DakarDave]

Thanks to stimpee for sending me the excel file for this setup..

Which one would you rather have! :)

<img src="http://members.roadfly.com/dakardave/cf_vf_ts_boost_curve.jpg"/>

-Dave

[DakarDave]

and just for one.. here's one with ts, cf and EMC turbo ... I eyeballed the EMC turbo chart from stimpee's orginal thread...

<img src="http://members.roadfly.org/dakardave/sc_tubo_boost_curve.jpg"/>

[stimpee]

Well, I'm sure Boris or EMC will come in with theirs, which at about 3k or 3.5k rpm will go flat to redline!

However the graph cannot show the "rubber band effect"!!



;)

Steve

[stimpee]

Jeez, I am too slow, posted it while I was posting...


Steve

[paul e]

well, it sure looks like the shape of the TS curve is MUCH closer to that of the Turbo than of the CF doesnt it.. I mean, we already knew it, but its nice to see it confirmed. We have to wait til redline to see what Eric sees at just 4000 rpms (8.5 psi) . And til 6000 rpms to see what you see at just 3500 (7 psi).

[DakarDave]

yup.. even with a "boost" bump.. the cf boost curve would still look very similar.. All the action happens up top... :(

[frankie1000]

looking at the TS graph there, it looks a little strange, i though the TS were better at producing boost than the Roots type?

With my setup, hit it at 1000 revs and i have 3psi of boost, i have my full boost of about 5 / 5.5 by 2000 revs.

i would imagine when i bump this up to 8psi it would be as good, perhaps developing 8psi by 3000revs.

always thought the TS had better development than Roots


anway, the TS is a sure winner.... Should of added a roots in there as well

[DakarDave]

Hi frankie1000 - It sounds like you have a Roots type supercharger installed. Do you have the instrumentation required to produce a RPM vs Boost graph? If you do, I'm sure everyone on this board would love to compare it to the twinscrew boost curve.

Feel free to email me: david_t_yee@yahoo.com

[paul e]

Good Job dave, compiling all possible FI boost curves.. come to think of it, i dont think ive Ever seen compiled a chart like this which has all the types together like this...I think Corky Bell has it, but all in different chapters, on different graphs.. I like compiling them together like youre doing..

[M3TurboCa]

Post Boris over lay I want to see how me made 8 psi by 3000rpm :)

[///3oris]

Post Boris over lay I want to see how me made 8 psi by 3000rpm :)

Mark, I don't know if it's "BY 3k RPM" I know it's right around it... there's only so much resolution I can get without proper instrumentation.

If someone has a spare MAP sensor, I'll definitely log everything. Especially if someone just has an external logger of some sort? I'm willing to travel up to an hour if someone has the eqipment.

Boris

EDIT: If you want, I can go do a quick run and video tape my boost gauge while I read out the RPM every 500rpm? Just for some 'rough' numbers?

[frankie1000]

i would love to be able to show a roots graph, but i dont have any instruments to record it. Would a Rolling Road have it to measure boost vs rpm?


but believe me, my M45 roots makes 3psi at 1000rpm upwards to full 5psi boost by 2000 - 2500

[M3TurboCa]

Boris I understand I thought you also has a LM1 sorry. I want to upgrade the map sensor I have 2 bar to 3.

I think its not so accurate was using it with my split sec led boost gauge before. :)

Even if you build full boost by 3500rpm that very efficient and would show on the over lay what a good size turbo can do.

With the larger HFM I get 1.5psi more boost at the same rpm. :) I can feel it coming in faster and harder. :)

[RAiMA]

Interesting :)

Here's the RT centrifugal setup

rpms - boost
2000 - 1.3PSI
2500 - 2.2PSI
3000 - 3.4PSI
3500 - 4.5PSI
4000 - 7.0PSI
4500 - 8.6PSI
5000 - 10.4PSI
5500 - 12.6PSI
6000 - 14.5PSI
6500 - 16.5PSI
7000 - 18.2PSI
7200 - 19.1PSI

Note: PSI rise rates can be increased by changing the pulley for an engine with a lower rev limiter.

[///3oris]

Boris I understand I thought you also has a LM1 sorry. I want to upgrade the map sensor I have 2 bar to 3.

I think its not so accurate was using it with my split sec led boost gauge before. :)

Even if you build full boost by 3500rpm that very efficient and would show on the over lay what a good size turbo can do.

With the larger HFM I get 1.5psi more boost at the same rpm. :) I can feel it coming in faster and harder. :)

Mark, I have an LM-1, just no MAP sensor!! :)

Anyway, check out the other thread... I just posted how fast my boost builds... looks like I was wrong... I hit max boost even before 3k... :eek

Boris

[TYE]

Im tired of seeing twin screw graphs, lets see some kits on the road. Sorry Steve, coudnt resist ;)

[stimpee]

i would love to be able to show a roots graph, but i dont have any instruments to record it. Would a Rolling Road have it to measure boost vs rpm?


but believe me, my M45 roots makes 3psi at 1000rpm upwards to full 5psi boost by 2000 - 2500

Frankie,

You have a 45CI blower on a 1.8/1.9L engine, I have a 98CI compressor on a 2.5L engine. Your blower is VERY likely spinning much further into it's peak VE range even at low rpm on your engine.

As I said, I will reserve final judgement until I see the TS curve on a 3.2...

Steve

[stimpee]

Im tired of seeing twin screw graphs, lets see some kits on the road. Sorry Steve, coudnt resist ;)

Get me 15+ people willing to commit a decent sized deposit, and I will have kits available in relatively short order. OBDII Software COULD still be an issue, but that can be worked out.

Can't afford to do it on a onesy twosey basis, 15-20 units would be the threshold for me to do this "on my own"...

However Tye, your point is taken!!

:help

Steve

[InterSpool]

Interesting :)

Here's the RT centrifugal setup

rpms - boost
2000 - 1.3PSI
2500 - 2.2PSI
3000 - 3.4PSI
3500 - 4.5PSI
4000 - 7.0PSI
4500 - 8.6PSI
5000 - 10.4PSI
5500 - 12.6PSI
6000 - 14.5PSI
6500 - 16.5PSI
7000 - 18.2PSI
7200 - 19.1PSI

Note: PSI rise rates can be increased by changing the pulley for an engine with a lower rev limiter.
On what engine??

[EMC]

Remember too that at that time I was using a 1.06 A/R exhaust housing....
What I like to show is a plot of the twin screw and my turbo chart just for a rough comparison.
http://www.rallyroad.net/images/Dyno/TurboandTScomparo.JPG
Alright...I'm sick as a dog and need to get back to sleep...

[diegom6]

Once again, Turbo Rules!!!

[stimpee]

Once again, Turbo Rules!!!

If you want the power delivery characteristics of a turbo (regardles of magnitude), then you are correct.

If not, then you are not correct!!

:stickoutt :stickoutt

BTW Eric, if ever possible, I would love to see that plot with the scales both starting at ZERO. I prefer graphs where the magnitude of the difference is scaled appropriately relative to the absolute magnitude!!

Steve

[diegom6]

Well that's true Steve, until today I can't resolve the problem of the Twin Screw or whateevr type of blower is in the Jeep, but that, 1 PSI jumpsinstantanly when I do WOT and love it!

I drove also a 2002 ///M 540i Supercharged (Centrifugal) Voretch unit, as well the armored X5 and the 540i S/C was a monster!!

However I keep in the Turbo side, I just find it more funny to drive and can't live with the idea of not boosting more just from a switch installed in the cockpit like doesn't the S/Cs....each models has it's advantages, that was disccused several times!! Matter the taste of each person!!

[stimpee]

Well that's true Steve, until today I can't resolve the problem of the Twin Screw or whateevr type of blower is in the Jeep, but that, 1 PSI jumpsinstantanly when I do WOT and love it!

I drove also a 2002 ///M 540i Supercharged (Centrifugal) Voretch unit, as well the armored X5 and the 540i S/C was a monster!!

However I keep in the Turbo side, I just find it more funny to drive and can't live with the idea of not boosting more just from a switch installed in the cockpit like doesn't the S/Cs....each models has it's advantages, that was disccused several times!! Matter the taste of each person!!


You got that right Diego!!

Anyway, did you get my responses to your Jeep stuff? Very weird...

Steve

[EMC]

BTW Eric, if ever possible, I would love to see that plot with the scales both starting at ZERO. I prefer graphs where the magnitude of the difference is scaled appropriately relative to the absolute magnitude!!

My car's idle was set at 900rpm's....can start earlier than that! Sorry. :stickoutt Those dynapacks aren't the best for making nice looking graphs. Time to go puke again.

[stimpee]

What I am saying Eric is to start the HP and torque graphs at Zero not at 225 and 113 on the Y axis.

Kind of like the graphs that show a 5 hp increase, but the y axis starts at 200 and the actual HP is 210. Makes the 5 hp diff look huge relative to the scale, but it is not as large.

Not saying your numbers are skewed that much, but my brain wants to see them with a y-axis that starts at ZERO!!

Steve

[Bad Bimr]

Get me 15+ people willing to commit a decent sized deposit, and I will have kits available in relatively short order. OBDII Software COULD still be an issue, but that can be worked out.

Can't afford to do it on a onesy twosey basis, 15-20 units would be the threshold for me to do this "on my own"...

However Tye, your point is taken!!

:help

Steve

OK, I will be number ONE. 14 more to to. Come on people.

[DocWyte]

Steve, how much would the kits be if you got the necessary orders?

[stimpee]

Hard to finalize without some commitments, etc, and without a HARD answer on the software side, but if I did this myself, I could sell for $7k with minimal risk.

If I sold kits with "software delete", I could drop that somewhat.

Steve

[DocWyte]

"software delete" Ouch! Any thoughts on what kinda power this would make on an M3?

[stimpee]

Results should be consistent with other well tuned (assuming good tuning) 8-9 psi setups, so low-mid 300's at the wheels depending on various variables.

I would expect 325+ on an OBDII M3 if all works well though...

Steve

[m3boost]

and just for one.. here's one with ts, cf and EMC turbo ... I eyeballed the EMC turbo chart from stimpee's orginal thread...

<img src="http://members.roadfly.org/dakardave/sc_tubo_boost_curve.jpg"/>


We're all so worried about the low rpms. All I know, is that shifting every gear at redline will bring you to 4500- 5000 rpm for the next shift. So it's full boost after every shift for bascially both the TS and turbo. No comment for the CS.

[InterSpool]

I totally agree. Even if your turbo whipped at 4500rpm (still 2500rpm under the curve and keeps you in peak torque after shifts) all you'd have to do is select the correct gear, mash the gas, and off you go. Since when is anyone cruising along at 45mph in 5th gear around 2000rpm and starts off a race without dropping a gear? Even if you built full boost at 2000rpm, you're still going to lose. What's the point?

[Bad Bimr]

I totally agree. Even if your turbo whipped at 4500rpm (still 2500rpm under the curve and keeps you in peak torque after shifts) all you'd have to do is select the correct gear, mash the gas, and off you go. Since when is anyone cruising along at 45mph in 5th gear around 2000rpm and starts off a race without dropping a gear? Even if you built full boost at 2000rpm, you're still going to lose. What's the point?

Sometimes the point is not about winning or losing. I guess as I get older speed is not my numer one priority. Car balance and drivability are things I prefer. It has been said time and time again, for all out power get a turbo. We should be happy taht soon we will have 3 different choices to choose from when it comes to our BMW's and FI.

[InterSpool]

Yep, choices are a good thing. I have a question about your future setup though, does Eurosport even know if the TS can run 18-20psi yet? What have their test results yielded?

[m3boost]

Sometimes the point is not about winning or losing. I guess as I get older speed is not my numer one priority. Car balance and drivability are things I prefer. It has been said time and time again, for all out power get a turbo. We should be happy taht soon we will have 3 different choices to choose from when it comes to our BMW's and FI.


Kind of reminds me when people say a bmw wasn't made for drag racing. I don't think any car is made for drag racing. The fun part is builting one yourself with the car of your choice. (not flaming) If speed wasn't your number one priority then why do you want 18-20 psi when an NA e36 m3 should be perfect for car balance and drivability. The fact is, young or old, we all love speed and are always trying find ways to be faster than the person next to you.

But I agree, we'll soon have more choices. The only problem that I currently find wrong with the TS is the ability to change boost with the flip of a switch. 18-20 psi is nice but not with 91 octane. I'm sure there is or will be a way to control boost. On my next project, I will probably use a TS 3.2 on my e30 m3. :)

[RAiMA]

On what engine??

That example was on the M44 engine. Larger superchargers are available to suit M3 engines of above 800hp.

[stimpee]

I totally agree. Even if your turbo whipped at 4500rpm (still 2500rpm under the curve and keeps you in peak torque after shifts) all you'd have to do is select the correct gear, mash the gas, and off you go. Since when is anyone cruising along at 45mph in 5th gear around 2000rpm and starts off a race without dropping a gear? Even if you built full boost at 2000rpm, you're still going to lose. What's the point?

For me, it is not about "the race". It is about cruising around at any speed, in any gear, and deciding I want to be "there" and mashing the gas and going. No muss, no fuss, no waiting, no nonlinear onset of boost if I mash it at low rpm, no feel of awesome top end rush due to the fact that there is little low end. The car feels like it has a V-8 in it. That is what I wanted, that is what I got...

Steve

[///3oris]

For me, it is not about "the race". It is about cruising around at any speed, in any gear, and deciding I want to be "there" and mashing the gas and going. No muss, no fuss, no waiting, no nonlinear onset of boost if I mash it at low rpm, no feel of awesome top end rush due to the fact that there is little low end. The car feels like it has a V-8 in it. That is what I wanted, that is what I got...

Steve

Steve, when I'm cruising around in 5th gear and don't feel like leaving it... I don't. I just step on the pedal and accelerate to "there" and it gets there pretty darn fast... I don't even have to press the throttle hard and feel that non-linear torque curve ;)

Boris

[stimpee]

As I said Boris, different strokes for different folks. If you are trying to convince me that I really want a turbo, you are wasting your time.

See below for a datalog I took this morning on the way into work. This is a 3rd gear pull. Some of the data channels are not working since I don't current have some of the channels hooked up. The x axis is TIME. You can look at the boost build, the temperatures into and out of the intercooler, and my EGT. The point I have selected on the graph is a few data points from the top end of the graph, and shows the actual numbers recorded in the windows below...

Too bad the TPS signal is not hooked up, you would be able to see the <50ms lag from when I go WOT until I have "full" boost for the given rpm...


http://www.dol.net/~stimpee/hurtigsc/boost_1.jpg

[DakarDave]

wow.. steve.. that's very cool data logging software there.... I like it...

[///3oris]

As I said Boris, different strokes for different folks. If you are trying to convince me that I really want a turbo, you are wasting your time.

No, Steve, I'm not trying to convince you of anything...

Nice datalog, I love all the inputs! :buttrock

Boris

[stimpee]

No, Steve, I'm not trying to convince you of anything...

Nice datalog, I love all the inputs! :buttrock

Boris

I'll make note of that and remember to refer to your post next time you are trying to convince me!!

:lol :lol :lol :lol :lol

:redspot

[///3oris]

I'll make note of that and remember to refer to your post next time you are trying to convince me!!

:lol :lol :lol :lol :lol

:redspot

No, you misread what I said. In this case I wasn't trying to convince you of anything. You made it sound like everything is inferior to TS since you can be cruising at like 2k RPM punch it and you're "there" since you have full boost. Well.. I drive around daily in the 2.5-3k range (I usually shift at 3k) and I never have problems getting from here to "there" even without downshifting. On the highway I'm pretty much always over 3k RPM and let me tell you... it's VERY fast even part throttle (too bad nothing short of driving the car can show you how it feels part throttle).

Boris

[stimpee]

Boris, my post above was meant as a joke. Remember the incessant chop busting?

If you want to take my posts as indicating that I think the TS is "superior", then so be it. The only thing I have EVER said, is that it is superior for ME, and I then try to indicate WHY that is so, and let people decide if that might be what they want or not...

Steve