Prompted by this thread https://www.scoobynet.com/scoobynet-...ml#post7976583 ....

Has anyone got RR dyno plots of:

UK MY05 2.0 STi
UK MY05 2.0 STi + PPP
UK MY05 2.0 STi + remap (e.g. Bob Rawle, Powerstation etc)
UK 2.5 STi
UK 2.5 STi + PPP
UK 2.5 STi + remap (e.g. Bob Rawle, Powerstation etc)
JDM 2.0 STi

all with no or "basic" mods (exhaust and filter)?

I've just added the dyno plot to my profile of my JDM 2.0 after its remap.

I know that this will not be an exact comparison, but it might be interesting ? It will at the very least show the "static" differences between the models, and allow an interesting debate between the twin- and single-scrollers

 

2ltr JDM MY03 Spec C (panel filter and backbox, JDM map, v power and octane booster)

316bhp and over 320lbs of torque, off hand i cant remember but was good

Tony

 

You saw mine Tim at Surrey RR totally factory standard and made 307/321 on a hot day

 

Just giving peak figures is worthless. Comparing dyno prints from different dyno's is even more worthless.

 

Here's an ecutek delta dash road dyno graph showing mine (STi 2.5) when std (green) and then remappped (see my profile). Figures are at the wheel.



Note the 2.5 - 3k rpm areas.
Remapped shows 280/290 lbft @ 2.5k rpm which jumps to 350/360 lbft @ 3k rpm - this would "stretch" a mapped 2 litre twin scroll.

Nick

 

Nah, a mapped 2ltr twin scroll car will push 360-370lbs of torque, upgrade the turbo and your looking at over 400lbs easy

Tony

 

BTW, I didn't bother to point out the 370-380 lb ft by 3.5k rpm

 

Didnt you know that the twin scroll cars produced 80% of their torque at 2500 rpm by 3500 your looking at a nice 370lbs thats the wonder of the twin scroll cars

Tony

 

I can't see this on graphs so far (linked thread to this and Webbys stage 1 graphs).
The extra 1/2 litre outweighs the twins scroll "early" torque.
If you have any other graphical info to suggest otherwise then please post it up - its the reason for this thread.

nick

 

This isn't about peak power or torque, more about how/when it is delivered: the shape of the graphs if you like.

So graphs are easy to see (rather than having to look at my profile) here's my twinscroll remap results.



This clearly shows the boost tailing off (turbo or induction - if you believe Bob Rawle it is induction as he managed to map his twinscroll to maintain 1.4bar once he fitted an RCM induction kit); and it also shows I have >300 lbft from 3500-6000 rpm.

 

And, for interest, here are plots from Surrey RR as per scoobytc's post above. After that RR day I discovered I had a split pipe to the 3 port BCS - once I fixed it, I lost a very noticeable amount of torgue at low rpm. In other words, the 1.7bar boost and 380lbft torque and not really representative...except they were adamant at SRR that my fuelling was spot on, so maybe a further rempa might allow that impressive torque figure after all

Of course, what it really does is, to a degree, support webby's view that comparing RR plots is pointless

 

The entire point is that the 2.5 doesnt outweigh the twin scroll's early torque, its .5 of a ltr down and produces more torque out of the box due to the headers being different plus the 2ltr is a stronger engine than the 2.5, uses less fuel yet produces the power of a bigger engine, you just have a bigger, thirstier engine, thats the difference

Tony

 

I'm easily confused - please show me some graphical info that's easier for me to follow.
It's also the point of this thread to post up some graphs that can either be compared or rejected as they come from many different RRs.

Nick

 

I will see if i can add the graph of my old spec c (unmapped, just a panel filter and about 2k on the clock, basically shows you at 1k rpm producing 75lbs of torque, at 1500rpm 100lbs of torque, at 2k 125lbs, at 2.5k 175lbs, 3k 225lbs, 3.5k 275bs, 3.8k 312lbs where it peaked.
Thats on a tight engine and still running the JDM map (official figures for the car were 276bhp and 290lbs of torque, on this its 299bhp and 312lbs)

Your other place to look is subaru japan, the standard model now produces 300bhp and 310lbs (last of the hawkeyes) compared to the 290bhp/300lbs on the 2.5, but it is all in the headers

Tony

 

Sorry tony, but here are some DynoDynamics (so a reasonably valid comparison) result snapshots from a 2.5 WRX with STI turbo on, exhaust and remap.

RPM--Torque(ftlb)
2000-180
2400-230
3200-360
4000-380
4800-380
5500-330
6400-270

Compared to the above graph for a twinsroll car flat out, it's way ahead 70ft-lb at 3200RPM.

Trying to compare your results from (I presume) Prosport's bosch rollers is somewhat flawed.

 

Have you a comparison from a standard car?
Remember mine was never mapped, ran the standard exhaust and only a panel filter, comparing it with a remapped car is well, stupid really but also take into consideration mine only had 2k on the clock when those figures were done, and it pretty much ran the same figures every time (when run in) it went on those rollers, how many other rr's do that?

Tony

 

Tim, what mods does your car have btw
Zen, i know where your coming from, but considering a JDM is still a 2ltr (and higher revving) my point is that just because its bigger does not make it better

Tony

 

It's all in my profile

But, basically: Milltek 3" decat, K&N panel filter, 3-port boost solenoid and a remap.

 

Twin scroll fan boy strikes again
"Tight engines" - my ****
That output appears to be identical to a std 2.5 engine, so the starting blocks are similar.
Let's hope that others haven't lost the will over this thread and have some graphs can In some way be comparable.

 

Twin scroll IS good, 2.5litre IS also good. 2.5 with twin scroll works even better, 2.5 with GIANT twin scroll turbo is great!

 

1st time on the rolling road my old car pulled 288bhp, added the panel filter and that went up to 299bhp, by the time she was loosened up (as of course engines are not tight when new 10k down the line) she was running 316bhp.
Remember its a 2ltr not a 2.5

Tony

PS, go have a look which way the turbo technology is going, see how many manufacturers are doing twin scroll engines now

 

I think the RCM Gobstopper runs a twinscroll doesn't it?

 

Just ashame that subaru dont think the same though if they made that 2.5 a little bigger (engine size, not capacity) for a bit more strenght, they could be onto something

Tim, im not sure, but its the way forward

Tony

 

I've only got an exhaust and a remap and I'm hitting almost 360lb/ft(not RR verified), also I think it's got a low 12 in it at it's current state of tune. I ran a 12.5@110 on my first ever attempt over the 1/4. I'm fitting a 3PBS and a Forge acutuator and going back to see AndyF on the 30th, so should maximise the torque from the turbo. Low down, mid range and top end this thing is very, very impressive, not bad for ~£1300 worth of mods.

 

What sort of boost are you running, and do you know how well it maintains that boost through the rev range?

Is your estimate of 360lb-ft based on Andy's software? Can he get you any plots?

 

Yeah that's estimating using Andy's software, which is give or take a few either way. I'm sure he could supply me with the plots, I'll ask when I see him at the end of the month. I prefer to do my comparisons on the 1/4 though, if I can do regular 12.1/2's then I know there's been an improvement.

Peak boost is 1.55.

 

Sounds like it may well be mapped to 1.4bar like mine, since mine peaks at around 1.5 too.

What's the purpose of the uprated actuator?

 

It's a similar mod to uprating your boost controller(solenoid), it should allow for a better/more accurate boost control. In theory it will allow me to run slightly more boost.

Check here - https://www.scoobynet.com/newage-imp...-part-2-a.html

 

. Thanks for the link

 

Some RR printouts of mine on here (the Ex BRD car):

https://www.scoobynet.com/projects-4...phase-2-a.html