wrx9181

iTrader: (2)

If you don't want faster spool more torque and more power don't have methanol ...ok Shaun we all no for whatever reason your methist ... ?...
But if you like going noticeably quicker ....
Get methed up mate and don't listen to him he's a methist lol

Shaun

Methist.... WTF is that!

juggers

iTrader: (1)

I think he means mentalist or menthalist!

MadUsa1

You didn't get any increase in lag?

How a about the power delivery, is it still as linear and as broad a powerband as standard?

wrx9181

iTrader: (2)

Not racist, ageist etc
Methist

johnfelstead

Just thought i would give an update to the thread after doing some work on a new Twin Scroll Turbo with Owen Developments and Chevron Motorsport.

We tried a couple of specs before finalising on my current one, i was looking to retain the OEM spool of the VF37 yet gain the top end of a turbo in the 450BHP range, i'm very happy with what we have ended up with.

My engine has been built with a high compression 9.1:1 to sharpen up off boost throttle response, so on pure v-power we are having to take a bit too much timing out to generate really good power and take full advantage of the turbo, it's probably worth a revisit to this with some octane booster to get the timing back (car was mapped the night before TOTB so didnt have time to try it, but we took 6 degrees out from my previous v-power+NF map), so on V-power we are circa 420BHP, 430lbft. A standard compresion engine on v-power should work better on pure V-power IMHO.

On a 20% mix of methanol with v-power it comes alive, it's producing at the wheels using Delta Dash 387BHP @ 6371rpm, 395lbft @ 3906rpm, this equates to aprox 468BHP and 478lbft at the flywheel.

At the moment the samco inlet hose i have is collapsing at the top end, so there is more to come from the turbo up top when that is sorted, we are also only using 50% waste gate duty mid range and are limiting the boost to the max it's safe to run on the OEM ECU with stock MAP sensor, the turbo will give more mid range than this.

In 4th gear it is producing 1 BAR of boost at 2900rpm, 1.85 BAR of boost at 3500rpm, it's holding 1.6 BAR at 6000rpm, 1.55 BAR at 7000rpm, even with the dodgy inlet hose. It hits those same figures in 3rd gear too with the use of MegaRom.

The really nice thing about this turbo setup is the way it drives, which you never really get a fair impresion of from full throttle dyno runs. Response is fanatastic, and what's really nice is the way you can be cruising in 6th and just boot it, there is no waiting for spool at normal motorway crusing speeds, it just picks it's heals up and goes.

I suspect based on previous experience, putting the car on a rolling road will bring the turbo spool 500rpm earlier than it shows on EcuTek Delta Dash Road Dyno, i'll try and get a run on a well known rolling road soon to put some plots up, but for now here is my road dyno results.

Dyno Test: 4th
==================

Maximum Wheel Power: 387.3 BHP @ 6371 RPM
Maximum Wheel Torque: 395.7 LbFt @ 3906 RPM
Power to weight ratio: 243.6 BHP per ton

Terminal velocity due to power: 199.5 mph

In Gear Acceleration:
40 - 60mph = 2.0 seconds
50 - 70mph = 1.8 seconds
60 - 80mph = 1.9 seconds
70 - 90mph = 2.1 seconds

Dyno Test: 3rd
==============

Maximum Wheel Power: 399.4 BHP @ 6995 RPM
Maximum Wheel Torque: 387.5 LbFt @ 4969 RPM
Power to weight ratio: 251.2 BHP per ton

Terminal velocity due to power: 201.6 mph

In Gear Acceleration:
30 - 50mph = 1.7 seconds
40 - 60mph = 1.4 seconds
50 - 70mph = 1.5 seconds
60 - 80mph = 1.7 seconds

Speed per 1000 RPM:
1st: 5.3 mph
2nd: 8.1 mph
3rd: 11.0 mph
4th: 14.4 mph
5th: 18.2 mph
6th: 22.9 mph

Maximum Speed per Gear:
1st: 43.6 mph
2nd: 66.7 mph
3rd: 90.0 mph
4th: 117.7 mph
5th: 149.2 mph
6th: 188.1 mph

Total Vehicle Mass: 1590kg
Drag Co-efficient: 0.37
Frontal Area: 2.20 square metres
Wheel/Tyre Setup: 235/45/17
Tyre Diameter: 643mm
Tyre Circumference: 2021mm
Engine Rev Limit: 8200
Test gear: 3 and 4
Max Speed of gear: 90MPH and 118 mph
Air Intake Temp: 17°C (62°F)
Atmospheric Pressure: 1.01 bar




Basic engine spec info:
MY05 JDM STi with stock heads and cams etc, rebuilt as a 2.1Litre at 9.1:1 compression.
Owen developments Twin Scroll Turbo
Chevron Motorsport TMIC
800cc EcuTek Injectors
BRD large MAF tube with K&N filter
Walbro 255 fuel pump
Stock FPR
Samco inlet hose
Stock ECU remapped by Bob Rawle using EcuTek Magarom
Engine rebuilt by myself and Chevron Motorsport

So there is now another Twin Scroll turbo option on the market.

johnfelstead

Also, just to add to the intercooler debate info, this is the Charge Temperature reading from my Chevron TMIC on the above 4th gear pull. With 1.85 BAR peak and 1.6+ BAR held charge temps go up just 6 degrees C.

juggers

iTrader: (1)

John that sounds like my dream setup, my cars currently runing 405bhp and 385ltb if I can get an extra 30ltb and a few more bhp and not sacrifice the spool up that would be great.

What turbo is it and how much?

johnfelstead

The turbo is a new development done specificaly for me, so wont be on the Owen website with a part number yet.

Get in touch with Chevron Motorsport in Stafford, they will be able to help with supply queries regarding pricing etc. Just mention you want to talk about the turbo done for me and they will be able to help.

Shaun

Interesting results John.

The only area I would tend to compare from your data currently (until you get your **** down to Surrey Rolling Road for a dyno run) is that of acceleration (assuming all things being equal).

Yours
40 - 60mph = 2.0
50 - 70mph = 1.8
60 - 80mph = 1.9
70 - 90mph = 2.1

Mine
40 - 60mph = 2.3
50 - 70mph = 1.9
60 - 80mph = 1.8
70 - 90mph = 2.0

This type of data is always good to look at.

50-90 look in the ballpark, which based on your road dyno results (which BHP wise appear very close to mine). The obvious area of pick-up is your 40-60 area. .3s quicker than mine, but then you're running more capacity, higher compression and higher octane fuel.

Since mine is only running VPower at the moment it's got to be worth me giving Meth a go now, however hard I try to resist!

I still think that the LM450 is an awesome turbo for a 2ltr.

juggers

iTrader: (1)

Edit I just read your engine build which is a 2.1 hence the extra torquees

Shaun

You quoted me but referenced John's engine I assume, because mine isn't a 2.1ltr.

juggers

iTrader: (1)

My bad

Shaun

John isn't just running more capacity, but he is also running higher compression. This can lend the set-up to make even more power / torque, especially with higher octane fuels (and don't forget he is running Meth as well).

When you consider I'm running a smaller engine, lower compression and lower octane fuel.....

Tidgy

thats an interesting result, 6 degrees seems to equate to 50% increase in a single pull, dread to think how multiple pulls would affect it.

Maz

iTrader: (34)

Do my eyes deceive me?! Shaun considering Methanol!

Shaun

Resistance is futile!!!

johnfelstead

LOL you can't use maths like that, a 6 degree increase on a pull like that is very good performance for any intercooler.

SRR are shut at the moment shaun, I'll get a run done soon.
What really impresses with this setup is the spool and responsivenes, when I get home I'll post a comparison of my VF37 on race fuel, that will give you a good idea of how good this setup is.

Shaun

For sure.... it will also be interesting to see your results once you get the inlet hose replaced for one that isn't made of tracing paper! lol

Tidgy

is the a comparision chart for a front mount around anywhere?

johnfelstead

Here is my current Owen Developments Turbo setup compared to how the engine was previously with my VF37 turbo on my 2.1 engine, run with a mix of race fuel (33%) and V-Power.

On Zens dyno it produced 399lbft @ 3550rpm, 354BHP @ 5925rpm with the VF37.



Here is the waste gate duty plot, to show you how much more this turbo could be producing if we could go past the limit of the OEM MAP sensor.

Shaun

John,
I'm not sure what that duty graph proves to be honest mate.

My car requires less duty than you run, yet it produces more boost than yours. My last map alteration held .1bar more boost and didn't make any more power. More boost does not always equal more power.

Even at 7k rpm. mine is only running 60% duty.

Between 4k - 5k rpm it runs 55% going doing to 49%. Minimum is 45% @ 4756 rpm.

Peak is 1.83bar and it still holds 1.7bar past 7k.

However... the more and more I'm wondering what difference a better fuel will make, to how this LM450 may end up responding.

Unless I'm missing something.... which with me is entirely going to be the case!

Shaun

That looks very nice mate.

johnfelstead

The waste gate duty plot is just there to illustrate the potential mid range, as you say, up top giving the turbo more duty wont equate to more power if the turbo is at it's peak flow.

When Bob had finished mapping and we popped the bonnet to remove all the det cans etc, he instantly said ah that makes sense, he had noticed the tell tale signs of the inlet pipe collapsing, which is slugging the top end, a quick squeeze of the pipe showed how rubbish it is. You could see marks on the inlet hose where it had gone out of shape. It should be interesting to see how the top end alters with a decent inlet pipe in place.

Shaun

Gotcha!

Get it sorted then!

Shaun

BTW.... have you got a log of your VPower map spool vs Meth map spool. That would be very interesting.

johnfelstead

Meth Map boost curve



V-Power boost curve.



I was logging a lot of params on this run so the trace looks a bit pointy, will redo this later but you should see spool is almost identical, bob gave it a bit more boost top end on methanol, the turbo could flow the same if we wanted to on v-power.

Once the inlet pipe is sorted and i stick a bit of NF in there we will do another mapping session and get a bit more out of the v-power map, we were concentrating on the meth map so i could get up to TOTB and run there safely.

I wanted to run without any octane booster on v-power, but i think the reduction in ignition due to high compression means it will benefit from a splash, so we can then up the ignition a few degrees and pick up a bit more response on v-power.

It's all very eary days, Bob has had very little time to map this so far, should be really good with the inlet pipe sorted and some more tweeks.

johnfelstead

It's worth adding that at the moment i have no Intercooler Water Sprays working as we removed the water tank to fit a catch can, i plan to fit a Spec C tank in the boot. It also has no heat shield on the turbo, we will be fitting a turbo blanket soon. So TMIC cooling asistance is none existant. It also has no cool air feed to the air filter, or any heat shielding to reduce under bonnet temps, so your worst case scenario really!

The Pink Ninja

iTrader: (23)

Looks good that John, Was impressed when you said of the 6deg increase on that chevron top mount when I spoke on sunday, Looks a well made bit of kit too

Good overall result on Sunday too, Even though you said you were driving like a ****

Lateral Performance

iTrader: (20)

John,


Great results, but I'm just curious to know what boost you intend running, if you're already 1.85bar in the mid' range ? Wouldn't 50% WG duty cycle be mainly down to the strength of the WG used ?


Mark.