Jobro

iTrader: (2)

I've been thinking about making this thread for a few months. Finally bit the bullet here goes.

I am proposing 2 standard tests.

Test#1: 4th gear 1000rpm go wide open throttle instantly
Test#2: 3rd gear, stand on throttle at 2000, 3000 and 4000rpm


The Rules

#0 Twin Rotors only (12A and 13B)

#1 No data no post

Data constitutes data recorded by your engine management system or your data logger, not eyeballing a boost gauge, no data don't care sorry.

#2 4th gear @ 1000rpm, pin the throttle wide open on flat road. Aim for a test temperature between 15C - 30C (59F-86F)

#3.0 Supply all relevant test conditions!
#3.1 Altitude
#3.2 Engine Size and port job prefer general style/size of port
#3.3 Manifold design (single divided)
#3.4 Exhaust size muffler style and noise level, catalytic or not, screamer pipes or not
#3.5 Time since rebuild and miles/kms since rebuild
#3.6 EXACT turbo specification, compressor wheel inducer+exducer dimensions, both turbine wheel dimensions, turbine A/R
#3.7 Ball bearing or not
#3.8 Dump pipe size
#3.9 Vehicle weight
#3.10 Tyre Brand and Model (specify if they are street, performance, r compounds radials etc)
#3.11 Tyre Size (205 50 R15, 255 40 R17 etc etc)
#3.12 Diff ratio

Test #2 will be measuring boost rise shape when the driver goes from 10% throttle at the engine speeds listed to 100% throttle instantly.

The point is you measure the time from whatever the steady state was to 66% or 90% of the peak value manifold pressure when using metric units of BARs absolute, 66% is probably going to be more consistant.


I will supply my own data and I am hoping for data from the other single turbo guys, especially 13BT, 13BRE's and 13BREW's using GT35R and larger turbos.

Barry Bordes

Jobro, you are in winter....... It was 100*F (38*C) in New Orleans yesterday.
That would make my intake temp about 42-44*C.
Some of us will have to wait a few months to test!
Barry

Barry Bordes

Jobro,
How about comparisons of a 10 second pull from 3000 RPM with a trace showing spool?
With temps and boost showing on the log?

arghx

iTrader: (3)

I agree that pulls from 1000rpm would be helpful. Many of the new turbo cars now hit full boost under 2000rpm.

Sesshoumaru

iTrader: (1)

62-1 .84 Ptrim BB
HKS Cast Manifold
Stock Port 13BREW
Open WG
2600-3800 rpm
-7psi - 16psi
ATS 91
CTS 183
4th gear
12 sec Trace

Thats the closest I have on laptop to what you are looking for.

I can probably run some of those scenarios.

Jobro

iTrader: (2)

Those are all great graphs. Now I can't find my own charts. I will have another look tomorrow they will be somewhere.

I suppose I could collate the raw data if everyone wanted to PM me for my email address and then email me the data.

I think we need to standardise the test to boost vs. rpm plot to 1000rpm if we can. To give you an idea my car makes 13psi @ 3000rpm under some conditions (not sure about during the standard test I'm proposing) when loaded up and I guess I want to see from other peoples results how much a larger turbo is going to loose out there.

If everyone does the 1000rpm wide open throttle test I can plot boost vs rpm for various turbos from say 1250rpm to as high as you are game to rev it and we will have a very balanced view of how big the 'torque/boost hole' is.

Barry does your car use a divided exhaust T4 turbo? What is it?

Sesshoumaru thanks for that result! Is your turbo turbonetics? Does it use the F165 turbine wheel? Got any pictures of it?

Barry Bordes

Raymond,
I have the usual 3000 rpm tests for my TO4S and TO4Z. (divided cast HKS)
You guys aren't worried about full throttle in 4th gear from 1000 rpm?
Seems like a lot of load in a range that is never used as such.
But I agree that it would show spool better... but possibly to the detriment of the engine.
Barry

Sesshoumaru

iTrader: (1)

Some updated logs -

It's a turbonetics without the F165 wheel.

Only the last 4k log showed a pull when I got my fuel and boost controller tuned (was out tuning).

It looks as though my AIT increase around 20 degrees.........

A couple things to keep in mind is injector staging and boost controllers.

I use Primary hold (primary injectors do not decrease when the secondaries come online). I've noticed I have positive pressure faster and you can't tell when you are in transition or boost.

Tweaking my boost controller I was able to alter my pressure rate increase a bit.

I would say 5-8psi is a good neutral reference point that would elimate most of those factors (especially people running off WG springs).

cewrx7r1

iTrader: (2)

#3.0 Hot Humid Texas Summer Day, starting air temp was 35C. Third gear run from about 2500 rpm. Flat road, two people in car.
#3.1 Altitude = about +50 above sea level; Katy, Texas
#3.2 13B-REW stock intake ports with barley ported exhaus.t
#3.3 Manifold design, short T3 A-Spec kit.
#3.4 Exhaust: 3" DP and MP with Racing Beat dual tip catback
#3.5 Time since rebuild and miles/kms since rebuild, rebuilt in 1999 with 48,800 miles.
#3.6 EXACT turbo specification, Garrett GT35R
Compressor:
Wheel Inducer Diameter: 61.4mm
Wheel Exducer Diameter: 82.0mm, Trim: 56, A/R: 0.70
Turbine Specs:
Wheel Diameter: 68.0mm, Trim: 84, A/R 1.06
#3.7 Ball bearing
#3.8 Dump pipe size, about 2.25" back into DP.
#3.9 Vehicle weight about 2800 lbs R1 FD
#3.10 Yokohama AD08
#3.11 255/40-17
#3.12 dif ratio3.909

16 psi run.

In 4th or 5th (.86) gear, it will reach max boost around 3600 rpm.

seandizzie

iTrader: (1)

Jobro I don't have any logs saved from that low of RPM, these are the lowest start points I have, engine is sitting on the bench at the moment. On the high way in 4th and 5th I see 15psi by 3500-to 3800 if I start from 2500, though I don't have a log of it. My computer crashed a few months ago and I lost a lot of stuff, these stayed for some reason??

1st pic- is 3rd gear from 2800rpm. target boost is 15psi.
2nd pic- is 2nd gear, from 2800rpm, then shifting into 3rd, 4th and 5th. Target boost is 18psi

3.0-These were done in June of 2011 so it was pretty warm out.
3.1- Florida, Right near da beach man
3.2- Cosmo irons, FD housing, and a Ported REW manifold
3.3-Its a 35r t-3 1.06 a-spec shorty,
3.4- 3inch exhaust.
3.5- About a year since last rebuild with 15,000 miles on it, very hard miles...
3.6-BB
3.7-Dumped straight off wastegate.
3.8-2800lbs
3.9-BFG g force sport
3.10-245/50/16
3.11-4.10

On the chart, the upper portion ( blue line) is Rpm (red line) is Knock. In the lower portion the Green line is Boost

cewrx7r1

iTrader: (2)

Same car and info except:
30C air temp instead of 35C
16.5 psi instad of 16psi
4th gear instead of 3rd gear.

Jobro

iTrader: (2)

#3.0 Temp was 25-30C. Fourth or Fifth gear run from 2000 rpm. slight uphill road, two people in car.
#3.1 Altitude = sea level
#3.2 12A tall port street ported
#3.3 Manifold design, S5 pattern divided
#3.4 Exhaust: 3" DP single centre offset truck muffler
#3.5 Time since rebuild and miles/kms since rebuild, rebuilt in 2005 with 40000 miles.
#3.6 EXACT turbo specification, V-Trim Highflow
Compressor:
Wheel Inducer Diameter: ~55.0mm
Wheel Exducer Diameter: 70.0mm, Trim: 60, A/R: 0.60
Turbine Specs:
Wheel Diameter: major 63.75mm, minor 54.61mm Trim: ~73, A/R 1.0
#3.7 Journal bearing
#3.8 Dump pipe size, 3", open gates.
#3.9 Vehicle weight about 2700 lbs sa22c (RX7 gsl + 2 passengers)
#3.10 Toyo R888
#3.11 185-60-R13
#3.12 diff ratio 4.444

Also this is on summer mix pump E85


After looking at my data I can see that unless someone is posting up a really responsive setup even 2000rpm should be heaps to show the low RPM boost hole.

Jobro

iTrader: (2)

I notice the difference between your 2 plots and I have seen that exact same trend myself. On a really cold night I can get 13psi 0.9bar @ 3000 in the higher gears, but the plot I have shared doesn't show that because it was a hot day.



Thanks to everyone that has posted so far. I just had a bit more of a look through the plots they are all great. There is a lot of information in here now.

If we could get a GT42 frame turbo in here that would be great.

seandizzie

iTrader: (1)

Jobo, how much boost are you running. Your kpa scaling in your chart seems off, it starts at 50 kpa, 7 psi, at no throttle???

Here is a log I found in 5th gear, its a totally different story than 2nd and 3rd. I start at 3300 rpm and by 3656rpm I have 1.00 bar. So in 5th I only need 300rpm to go from full vacum to 1 bar of boost in 5th. It was cold out though, winter of 2010.

Exact turbo spec, 61.4mm inducer 82mm exducer, 68mm turbine. 84 trim 1.06 a/r

Jobro

iTrader: (2)

I'm using kPA absolute. Really everyone in the turbocharged and supercharged world should be talking in kPA absolute. Base air pressure where I am is close enough 101.3kpa.

So generally 0-100kpa = vacuum to 0psi

100kpa through 200kpa = 0psi through 14.5psi

1kpa=0.145psi

That plot was with a 1.3 bar spring set in the wastegates on a reasonably hot day.