Twin scroll turbo upgrade MD321 billet or SC42 billet or LM420 billet?
02 August 2012, 03:24 PM
#91
Hi Mark, I may look at running more boost in future, I havn't decided yet. We stopped there due to the limits of the OEM MAP sensor, to go further will require a different MAP sensor. The engine should take more safely.
The waste gate duty figure doesn't really mean much, I was just using it as an illustration of how the turbo is being driven and has some room to have let it build more boost. I don't fancy disconecting the wastegate control to see what it would produce uncontroled.
The waste gate duty figure doesn't really mean much, I was just using it as an illustration of how the turbo is being driven and has some room to have let it build more boost. I don't fancy disconecting the wastegate control to see what it would produce uncontroled.
11 August 2012, 05:29 PM
#92
Charlie's back, so i poped over to Surrey Rolling Road for a power run.
Below are the plots for V-Power and V-Power + 20% Methanol mix.
Some notes on the run:
It's probably one of the hottest days of the year today, inlet and ambient temps were 24 degrees C. My intercooler charge temps were 10 degrees higher than seen on the road straight after the Rolling Road run. We had a touch of ignition retard on the rollers i dont see on the road.
We discovered an issue with the fueling mixture being too rich after i put the methanol in the fuel tank, so the V-Power graph is slightly down on what it should be, an ECU reset sorted the fueling out.
I did a Road dyno run on the way home on my usual bit of road, so now have a nice reference to use to get some representative of SRR figures from my Road Dyno.
I also took Datalogs during the Rolling Road runs and on the road on the way home, the turbo spools 150rpm sooner on the road and produces 0.1BAR more boost and has a 3000rpm higher peak turbo speed.
Early days yet with the setup, but it looks really good considering the lack of heat protection and Heat Soak, which will be improved on soon.
Figures today were 457 BHP @ 6500rpm, 465 LbFt @ 3750rpm on V-Power + 20% meth
It looks like it's going to be 405BHP @ 6500rpm 420lbft at 3750rpm on V-Power, spool was slightly faster on V-Power.
Power and Torque curves for V-Power and Methanol mix
Power and Boost curves for V-Power and Methanol mix
Next stage is to reinstate the TMIC water sprays by fitting a Spec C water tank in the boot. I'll also install a 4 BAR map sensor to allow us to exploit the turbo potential further, install a turbo blanket to reduce the TMIC heat soak and generally help with under bonnet temperatures, install a better inlet pipe that wont collapse and then map the engine using the Turbo Speed as a reference.
My turbo has a Garrett turbo speed sensor fitted, it's currently running 15,000 rpm below target at peak boost due to the limits of the OEM boost sensor, speed at 7000 engine rpm is spot on, so gains to come from peak boost to 7K rpm yet.
Below are the plots for V-Power and V-Power + 20% Methanol mix.
Some notes on the run:
It's probably one of the hottest days of the year today, inlet and ambient temps were 24 degrees C. My intercooler charge temps were 10 degrees higher than seen on the road straight after the Rolling Road run. We had a touch of ignition retard on the rollers i dont see on the road.
We discovered an issue with the fueling mixture being too rich after i put the methanol in the fuel tank, so the V-Power graph is slightly down on what it should be, an ECU reset sorted the fueling out.
I did a Road dyno run on the way home on my usual bit of road, so now have a nice reference to use to get some representative of SRR figures from my Road Dyno.
I also took Datalogs during the Rolling Road runs and on the road on the way home, the turbo spools 150rpm sooner on the road and produces 0.1BAR more boost and has a 3000rpm higher peak turbo speed.
Early days yet with the setup, but it looks really good considering the lack of heat protection and Heat Soak, which will be improved on soon.
Figures today were 457 BHP @ 6500rpm, 465 LbFt @ 3750rpm on V-Power + 20% meth
It looks like it's going to be 405BHP @ 6500rpm 420lbft at 3750rpm on V-Power, spool was slightly faster on V-Power.
Power and Torque curves for V-Power and Methanol mix
Power and Boost curves for V-Power and Methanol mix
Next stage is to reinstate the TMIC water sprays by fitting a Spec C water tank in the boot. I'll also install a 4 BAR map sensor to allow us to exploit the turbo potential further, install a turbo blanket to reduce the TMIC heat soak and generally help with under bonnet temperatures, install a better inlet pipe that wont collapse and then map the engine using the Turbo Speed as a reference.
My turbo has a Garrett turbo speed sensor fitted, it's currently running 15,000 rpm below target at peak boost due to the limits of the OEM boost sensor, speed at 7000 engine rpm is spot on, so gains to come from peak boost to 7K rpm yet.
11 August 2012, 07:41 PM
#94
No excuses here Shaun, just information to put in context what the graphs show.
As you know i dont do Rolling Roads normally, and the engine is mapped on the road so not optimised for the Rollers, so just a bit of info for people who do like to compare RR graphs to see.
Next changes should certainly improve the heat management and pick up even more mid range, where this setup already scores exceptionally well.
As you know i dont do Rolling Roads normally, and the engine is mapped on the road so not optimised for the Rollers, so just a bit of info for people who do like to compare RR graphs to see.
Next changes should certainly improve the heat management and pick up even more mid range, where this setup already scores exceptionally well.
11 August 2012, 08:45 PM
#95
Scooby Regular
John you need to go out and get pissed!! When you're starting to "miss" the banter remarks, you know it's time to take a break. 
Anyway (you grumpy git).....
Your spool is certainly very good.
Is your core more akin to a 420bhp turbo as your graphs appear (to me) to insinuate it.
Anyway (you grumpy git).....
Your spool is certainly very good.
Is your core more akin to a 420bhp turbo as your graphs appear (to me) to insinuate it.
12 August 2012, 12:49 AM
#97
You dont have to get pissed to relax m8.
I've never been into chasing the power figures Shaun, i've been trying to help come up with a package that builds on what the Twin Scrolls are best at, which is great spool, mid range torque and drivability. To me, if you want to go chasing top end power at the expense of the bottom end you are losing the essence of whats so great about the twin scroll JDM's.
So it's not about being the equivilent of an SC46, LM450, MD321 etc. I wanted something that worked like a twin scroll at the bottom end, something that spooled quickly and produced torque in the rpm range i use most on the road and out of corners in the sprints, yet can run to 8krpm if needed and has the strength of the JDM spec engines. Remember this is my 12K mile per year only road car that i also happen to do the ocasional sprint with, it's a genuine full weight comfort barge that is able to compete well with more powerful and much lighter competitors in the sprints.
It looks like we have pretty much achieved what we targeted, being able to match the response and spool of a VF37, but provide a big jump up in torque, with the ability to carry on that torque curve right up the rev range.
As a comparison my 2.1 on a VF37 had 399 lbft @ 3550rpm and 354BHP @ 5925rpm when run on a mix of V-power and 33% race fuel, which was already pretty much the best torque being seen out of the VF37. Great torque but it couldnt sustain it. We now have 465 lbft @ 3750 rpm and 457BHP @ 6550rpm, thats a gain of 66 LbFt and 103 BHP with no loss of spool and it can sustain the torque.
As i've always said though, rolling road figures dont show you how a package drives, and in that respect this package is impressive, through the gears it's very quick with no lag, the response at cruising speeds when you need to just accelerate without waiting for the turbo to spool is one of the best things about it.
Cheers Fud.
I've never been into chasing the power figures Shaun, i've been trying to help come up with a package that builds on what the Twin Scrolls are best at, which is great spool, mid range torque and drivability. To me, if you want to go chasing top end power at the expense of the bottom end you are losing the essence of whats so great about the twin scroll JDM's.
So it's not about being the equivilent of an SC46, LM450, MD321 etc. I wanted something that worked like a twin scroll at the bottom end, something that spooled quickly and produced torque in the rpm range i use most on the road and out of corners in the sprints, yet can run to 8krpm if needed and has the strength of the JDM spec engines. Remember this is my 12K mile per year only road car that i also happen to do the ocasional sprint with, it's a genuine full weight comfort barge that is able to compete well with more powerful and much lighter competitors in the sprints.
It looks like we have pretty much achieved what we targeted, being able to match the response and spool of a VF37, but provide a big jump up in torque, with the ability to carry on that torque curve right up the rev range.
As a comparison my 2.1 on a VF37 had 399 lbft @ 3550rpm and 354BHP @ 5925rpm when run on a mix of V-power and 33% race fuel, which was already pretty much the best torque being seen out of the VF37. Great torque but it couldnt sustain it. We now have 465 lbft @ 3750 rpm and 457BHP @ 6550rpm, thats a gain of 66 LbFt and 103 BHP with no loss of spool and it can sustain the torque.
As i've always said though, rolling road figures dont show you how a package drives, and in that respect this package is impressive, through the gears it's very quick with no lag, the response at cruising speeds when you need to just accelerate without waiting for the turbo to spool is one of the best things about it.
Cheers Fud.
12 August 2012, 01:10 PM
#98
The spool is certainly very impressive John.
I know we're not comparing the same thing (2.5 vs 2.1, Litchfield LM480 vs Owen Developments, 10% meth vs 20% meth) but my available torque/rpm spread is very very similar to yours (albeit a higher absolute peak at 524lbft)...
...but your spool is 600-700rpm better
I can see that for a sprint setup your build must now be absolutely awesome
I know we're not comparing the same thing (2.5 vs 2.1, Litchfield LM480 vs Owen Developments, 10% meth vs 20% meth) but my available torque/rpm spread is very very similar to yours (albeit a higher absolute peak at 524lbft)...
...but your spool is 600-700rpm better
I can see that for a sprint setup your build must now be absolutely awesome
12 August 2012, 01:36 PM
#99
It makes for an awesome road setup too Tim.
My cruise rpm is usually between 3000rpm and 4000rpm, if i want to make a quick acceleration i just put my foot down and it's off, lots of uprated engine setups dont allow that, you have to shift down to get any response at normal road speeds, by which time i've well and truly buggered off! That 3-4k torque band is really important on the road, even more so with UK gearing.
I think people lose sight of what makes a great road engine, i learnt this a long time ago when i was playing with Sierra Cosworths, higher power packages on those were often far slower in the real world.
I'm never going to win any bar arguments about power with this setup (although 457BHP isnt too shabby ), but i dont care about that.
A good 2.5 can also work really nicely as an allrounder, as you have found out. It would actually be quite good fun to do some side by side acceleration runs with our two cars at road legal speeds. I did this with someone else once who had a suposedly higher spec to my VF37 still on the 2.0 engine spec, mine anialated it.
My cruise rpm is usually between 3000rpm and 4000rpm, if i want to make a quick acceleration i just put my foot down and it's off, lots of uprated engine setups dont allow that, you have to shift down to get any response at normal road speeds, by which time i've well and truly buggered off!
That 3-4k torque band is really important on the road, even more so with UK gearing.I think people lose sight of what makes a great road engine, i learnt this a long time ago when i was playing with Sierra Cosworths, higher power packages on those were often far slower in the real world.
I'm never going to win any bar arguments about power with this setup (although 457BHP isnt too shabby
), but i dont care about that. A good 2.5 can also work really nicely as an allrounder, as you have found out. It would actually be quite good fun to do some side by side acceleration runs with our two cars at road legal speeds. I did this with someone else once who had a suposedly higher spec to my VF37 still on the 2.0 engine spec, mine anialated it.
12 August 2012, 02:44 PM
#101
A good 2.5 can also work really nicely as an allrounder, as you have found out. It would actually be quite good fun to do some side by side acceleration runs with our two cars at road legal speeds. I did this with someone else once who had a suposedly higher spec to my VF37 still on the 2.0 engine spec, mine anialated it.
One measure might be the TOTB 1/4 mile times, where - IIRC - you did a 12.something I think, whereas I did sub-12s...but with some ECU trickery to assist. So maybe might conclude that through the gears the cars are similar? Or is that too simplistic?
A 30-130 would be more realistic of course, but not something we can easilly - legally - measure.
Once my car is up and running again, I'll log some in-gear acceleration times for interest. I may also try a 20% meth map to see what the effect on spool is
My conclusion, FWIW, after many years of agonising over my turbo choice is that if you *already* have a twinscroll setup then an LM450, or LM480, or SC46 or, now, the Owen turbo as on yours, make for an excellent upgrade. But if you're running single scroll already there are plenty of excellent turbo options out there and it is really not worth the hassle of changing over to a twin scroll/entry. YMMV
12 August 2012, 02:50 PM
#102
I'm rubish at 1/4 mile, so i wouldnt use that as a reference. (it did 1.60s 60ft, 12.11s 113MPH 1/4 mile with 1600kg on road tyres running 3 degrees negative camber)
Do any of the single scroll turbo setups spool like my Twin Scroll and produce torque in a similar way to mine?
Do any of the single scroll turbo setups spool like my Twin Scroll and produce torque in a similar way to mine?
Last edited by johnfelstead; 12 August 2012 at 02:52 PM.
12 August 2012, 03:50 PM
#104
The SC46 Twin Scroll is no where near as good as mine at spool or usable torque, it has more top end power potential. SC42 Twin Scroll i have seen on 20% methanol cant match mine for spool, torque or power.
The SC single scrolls are getting great results, it looks like an SC46 single scroll on a 2.5litre has slightly slower spool to my 2.1 litre setup, it's damn good for a Single, not found one on a 2.1 yet.
The SC single scrolls are getting great results, it looks like an SC46 single scroll on a 2.5litre has slightly slower spool to my 2.1 litre setup, it's damn good for a Single, not found one on a 2.1 yet.
12 August 2012, 04:41 PM
#105
Scooby Regular
The SC46 Twin Scroll is no where near as good as mine at spool or usable torque, it has more top end power potential. SC42 Twin Scroll i have seen on 20% methanol cant match mine for spool, torque or power.
The SC single scrolls are getting great results, it looks like an SC46 single scroll on a 2.5litre has slightly slower spool to my 2.1 litre setup, it's damn good for a Single, not found one on a 2.1 yet.
The SC single scrolls are getting great results, it looks like an SC46 single scroll on a 2.5litre has slightly slower spool to my 2.1 litre setup, it's damn good for a Single, not found one on a 2.1 yet.
1 bar by 3000rpm on the dyno and it makes a fair bit more power too, Vpower only on this one.
http://s40.photobucket.com/albums/e2...0SC46Boost.jpg
It's hardly surprising given the larger engine size, so don't think that I am in any way saying your's is poor. It appears to work very,very well for your demands upon it !
12 August 2012, 04:50 PM
#106
Mine hits 1BAR at 3000rpm on V-Power too Martyn on the dyno, and in 11 degrees C hotter Ambient Air Temperatures than your 2.5 graph, it spools 150rpm earier on the road and will hit 1.85BAR at 3500rpm on the road.
Much more to come yet once we have the 4 BAR MAP sensor installed and map the turbo for it's most eficient speed, rather than the current situation where we were limited by the OEM boost sensor.
Much more to come yet once we have the 4 BAR MAP sensor installed and map the turbo for it's most eficient speed, rather than the current situation where we were limited by the OEM boost sensor.
Last edited by johnfelstead; 12 August 2012 at 05:00 PM.
12 August 2012, 05:03 PM
#107
I'm rubish at 1/4 mile, so i wouldnt use that as a reference. (it did 1.60s 60ft, 12.11s 113MPH 1/4 mile with 1600kg on road tyres running 3 degrees negative camber)
Do any of the single scroll turbo setups spool like my Twin Scroll and produce torque in a similar way to mine?
Do any of the single scroll turbo setups spool like my Twin Scroll and produce torque in a similar way to mine?
I did this first couple of hrs on the sat witha brimmed tank of fuel also.
12 August 2012, 05:08 PM
#108
John must admit nice figures and nice competition to the SC,MD or LM.
But must say too,you are running Chevron TMIC and many people wouldn't be prepare to spend this amount money on the TMIC only,but agree Chevron TMIC kit is probably one of the best TMIC
We are running single scroll MDX321T and we are happy with 490bhp,with better up pipe we can gain on spool up and with better heads we can gain too on the top end
Here are two graph
V-Power
20% Methanol
On road turbo spool much better than on those dyno graphs
Jura
12 August 2012, 05:10 PM
#109
My tank was brimmed too (with 10 litres more than you and carrying more car weight as yours is a Spec C, mine a full fat JDM STi), i was getting a lot of fuel surge on the handling course so just filled it right up. I'm far too easy on the car for 1/4 mile runs FUD, i never launch the car hard or smash it through the gears, probably how i've managed to do the many hundreds of sprint launches without breaking anything in the transmition or drivetrain in the 3 1/2 years and 40K+ miles i've done whilst i've owned the car.
Last edited by johnfelstead; 12 August 2012 at 05:30 PM.
12 August 2012, 05:17 PM
#110
Spool is well down on mine Jura, as is the torque in the 3-4K range looking at your power curve.
Yes i am using a Chevron TMIC, it works briliantly on the road, it was suffering a bit on the Rolling Road though, running higher charge temps than i see on the road in the same ambients. You FMIC boys dont suffer from that on the rollers, so will be gaining a bit in the dyno queen world because of that
Just checked my datalogs, charge temps were as follows with me doing a 4th gear pull on the road just after the Rollers session, so the same 24 degree C Ambient temperature.
Rollers
Start of run in 4th: 29 degrees C
End of run in 4th: 39 degrees C
Road
Start of run in 4th: 25 degrees C
End of run in 4th: 32 degrees C
Yes i am using a Chevron TMIC, it works briliantly on the road, it was suffering a bit on the Rolling Road though, running higher charge temps than i see on the road in the same ambients. You FMIC boys dont suffer from that on the rollers, so will be gaining a bit in the dyno queen world because of that
Just checked my datalogs, charge temps were as follows with me doing a 4th gear pull on the road just after the Rollers session, so the same 24 degree C Ambient temperature.
Rollers
Start of run in 4th: 29 degrees C
End of run in 4th: 39 degrees C
Road
Start of run in 4th: 25 degrees C
End of run in 4th: 32 degrees C
Last edited by johnfelstead; 12 August 2012 at 05:49 PM.
12 August 2012, 05:17 PM
#111
true.
My tank was brimmed too, i was getting a lot of fuel surge on the handling course so just filled it right up. I'm far too easy on the car for 1/4 mile runs FUD, i never launch the car hard or smash it through the gears, probably how i've managed to do the many hundreds of sprint launches without breaking anything in the transmition or drivetrain in the 3 1/2 years and 40K+ miles i've done whilst i've owned the car.
But now im glad i didnt break anything,Like you say your'e cars lasted well and done many miles before the recent change in engine and mod's
.
12 August 2012, 06:20 PM
#114
A 1.6 60ft is a very hard launch Jon? Surprising though as with a quicker 60ft than me and a lot more power, you run the same time as me. Does your car really weigh in at 1600kg? Why so heavy?
Love how much camber you're running. I set my camber bolts at 3deg and my alignment place told me it was too much and dialled it back
Love how much camber you're running. I set my camber bolts at 3deg and my alignment place told me it was too much and dialled it back
12 August 2012, 06:32 PM
#115
12 August 2012, 06:52 PM
#116
A 1.6 60ft is a very hard launch Jon? Surprising though as with a quicker 60ft than me and a lot more power, you run the same time as me. Does your car really weigh in at 1600kg? Why so heavy?
Love how much camber you're running. I set my camber bolts at 3deg and my alignment place told me it was too much and dialled it back
Love how much camber you're running. I set my camber bolts at 3deg and my alignment place told me it was too much and dialled it back
The weight is based on the car being 1450kg, i've eaten too many pies so weigh 97kg at the moment and then a full tank of fuel which weighs 42kg, so a total of 1579kg actually. Weight does make quite a difference on the drag strip.
Acording to one of the online 1/4 mile calculators i should be doing 12.26s and 116MPH for my power/weight, so fairly close to the mark.
A Spec C of the same year with the same power should be doing 12.02s and 118MPH using the same calculator.
I wouldnt run 3 degrees negative on the road, i just set that for the Handling course and didnt knock it off for the drag as i was never going to score anything on there, just did the runs for a bit of fun at the end of the day.
12 August 2012, 07:00 PM
#117
Fair enough. I've only ever once ran a 1.6 60ft, all my other runs are 1.7 pretty much every time. What online calculator do you use out of interest?
I wish an easy launch would net me a quicker time, but I obviously lack the low end grunt that you have.
I wish an easy launch would net me a quicker time, but I obviously lack the low end grunt that you have.
12 August 2012, 07:23 PM
#118
I did 3 runs, all 1.6's.
Just checked the official results and i actually beat BIG FUD's time on the same day in the same conditions (i only ran sunday)
C70 John Felstead Subaru Impreza JDM STi 12.16 113
C60 Mark Ward Subaru Impreza Spec C 12.19 112
the calculator is at http://www.torquestats.com/modified/...pid=calculator
Just checked the official results and i actually beat BIG FUD's time on the same day in the same conditions (i only ran sunday)
C70 John Felstead Subaru Impreza JDM STi 12.16 113
C60 Mark Ward Subaru Impreza Spec C 12.19 112
the calculator is at http://www.torquestats.com/modified/...pid=calculator
Last edited by johnfelstead; 12 August 2012 at 07:31 PM.