2 litre classic GT30 hybrid



2.5 classic MD321T+



2.5 newage MD321T+



Banny

 

why is bhp and torque so low? reason i ask is i was advised to get one of these turbos but cant see the point with these figures plus "wasting" 2k+ inc remap

 

I think tubular headers would help that setup achieve better figures.

Banny

 

Banny - is that delta dash graph REALLY in wheel output?
I'm seeing more and more DD graphs that are flywheel power but the title reads as wheel output. Is this actually changeable in Ecutek for Pros or just a "feature" that needs to be sorting.

I think I've found some DD road dynos for a Std Blobeye Spec C and my Spec D when brand new - i'll post them up later.

Oh Mr Burns - I can't wait for the excuses when I do

Nick

 

Is it at the flywheel, do not think it is changeable at the moment and needs to be sorted.

Banny

 

Quote:

Originally Posted by johnfelstead

Seriously dodgy boost control on show there. When i put the decat on my twin scroll i only did one pull at full throttle just prior to the first flash to check the stock setup had no isues, it felt exactly as that shows, surging up and down to the peak torque point.

Get it remapped, you wont believe the difference, torque will be up around 390lbft and smooth as silk if it's done well.

Thanks for the comment John. As ever helpful advice in your posts based on your considerable knowledge.

The car was ECUTeK re-mapped post the decat, (although without the benefit of the dyno readings subsequently obtained a few weeks after mapping).

I will now check this out with the mapper!

 

Something not right there. I'm producing 414bhp and 377 torque (Zen's rollers) on a standard 2L engine running a 321H and 1.75 bar peak boost. OK, it's mapped for a splash of methanol, but would have expected better figures from a T on a forged engine

 

I didn't say there are any ceilings in the hawkeye ECU's Duncan, i am saying you might not have the option to use the megarom, which gives you access to individual gear based boost maps (4 for each gear) and the ability to run two maps on the ECU.

I would expect the 321T will be laggy compared to a 321H, it's more suited to a 2.5 engine if lag is your concern.

 

Thanks, i'm a bit confused. Is the dyno plot you posted post a remap or prior to the remap?

Another way to get a plot like yours is if you are getting wheelspin on the dyno, but i'd expect the operator to tell you that and do another run.

 

As they say lag is foreplay

The car needs some headers real bad and is only running 18 degrees of timing on v5 heads when it should be able to run about 23.

This will help with spool and take power up to 450 with out having to change the boost.

For less lag ill run a meth 2nd map but as the car will see track day's only and no sata pod days the lag is not an issues.

Ash

 

Quote:

Originally Posted by johnfelstead

Thanks, i'm a bit confused. Is the dyno plot you posted post a remap or prior to the remap?

Another way to get a plot like yours is if you are getting wheelspin on the dyno, but i'd expect the operator to tell you that and do another run.

Post ECUTek remap. No wheel spin encountered and best of 2 runs. I am checking it out; thanks again.

 

The below graphs "hopefully" address the superior stance that some have over a twin scroll turbo performance at low revs.
There are as close a comparison as I can dig up without the complication of mods getting in the way.
Both are Ecutek road dynos runs, but are unlikely to be under the exactly the same running conditions, so no doubt there are points to be raised?

I've gone for comments on shape and rev points rather than absolute figures:



Graph on left is a totally standard 1,000 mile 06 UK STi.
Graph on right is labelled as Spec C VF37 + mods. The blue lines are those being used for comparison.

The UK STi brings in torque far earlier than the Spec C.
The spread ranges of torque (220/200/180) is the same for each car, it just starts some 800-900 rpm earlier on the UK car.
The Spec C comes into its own after 5500 rpm. So much for the 280 PS book figure
The STi just dies at this point, which is very noticeable on the road. Even with the first remap and other work, I found the car still struggled noticeably at these revs. The recent TD05/20g has now removed that issue.

It may be that the comments on 2.5 lower torque vs. 2.0 TS are based on upgrade 2.5 bottoms, rather than the complete 06> packages?

Nick

 

Yours looks like in 4th gear. The spec C looks like 3rd gear as the sample rate is pretty chronic.

Depends on the 'mods' for the spec c but I dont think it is all that. Full boost at 4500 ?? that's a bit girlie isnt it ?

 

Thanks for the comment

 

Ok - I see what you mean about the curve detail. So if I slip in a 3rd gear run for the UK 2.5 STi:



The 3rd gear spool drops its advantage by about 200 rpm but there is a higher torque max bump and also improvement in top end power...

I have no idea what the additional mods were on the Spec C red curves. I captured the p[lot as I was going to put a VF37 on my last car ( 03 WRX with VF35, but the changeover cost was too much for the benefits.

 

That's because less power is being absorbed by transmission losses / tyres etc.

Pumping your tyres up makes a difference for the road dyno runs

 

Looked and laughed at those graphs
To start with the spec c doesnt run a vf37 turbo, it runs a vf36, and my last one (jap map) with 1800 miles on the clock produced 300lbs of torque and 289bhp, it also produced better torque lower than that one shown there, much better though i "may" have a graph at home of one of the runs, but im not at home this week

Tony

 

This seems to have become an argement of twin scroll vs single scroll. There is no argument, twin scroll wins IMHO.

if you want the best of both worlds a fully sorted 2.5 with twin scroll turbo is awesome, however, it's much more difficult to make a 2.5 reliable, in the same way it's more difficult to make a 2.0 more torquey. Spending £3k on a nitrous system definitely works on the Gobstopper, but to put it into perspective, a 100shot of nitrous at 100% lasts ONE MINUTE!

A well setup 2.5 with the right turbo can offer a great drive and spread of torque, along with good high RPM power.

 

Tony

 

How about a destroked 2.3, would that not be best of both worlds Paul?

Banny

 

You just can't tell.

I've mapped 2.3 engines that seem to respond averagely, 2.5 engines that seem no better than a good 2.0, and 2.5 engines that seem on the face of it to be more efficient per CC than any alternative with the exact same supporting components.

It's so critical to get everything balanced. The Zen car has pretty well sorted, the turbo works well with the engine, and the cams, the headers, the compresssion ratio and the fuel. The Gobstopper takes a different route but gets equally impressive results by ensuring that the whole works well together, it works around the excellent nitrous system, and makes the best use of the fuel.

It is not enough to simply have a bullet proof engine with all the right components if they don't combine to give you something more than the sum of the parts.

How very Zen like

 

Like the way you think Paul

Banny

 

Very well put Paul.

If you want to compare Road Dyno runs you need to have the cars being subjected to the same load. It's no good using 3rd for one and 4th for another as the 4th gear run will always pull the turbo in harder (using the same gearing on both cars), unless you have some compensation in the boost control for lower load(AVCR set for gear judge or megarom for example).

 

Through all of this "2.0l block is strongest" lark I'm suprised nobody has uttered the words "open deck block" or "closed deck block" (or sem-closed ).

Which of course opens up another tin of worms; Metallurgically better alloy and better quality casting vs poorer quality casting and alloy - but greater gasket mating areas.....

 

John, the second picture I posted has a 3rd gear UK STi plot on the left instead. Its now "like for like" as far as I can get.
I just want to see a couple of comparative graphs that can be pointed to and comments made about what are the good points on each set-up.
The graphs I've put up "hopefully" suggest that a std 2.5 SST engined car has the better road manners and a std 2.0 TST car would make the better track tool.

Since there are a number of Tunerz dropping in this thread, would it not be too difficult for them to open up their vast libraries of dyno or road runs that are comparable and demonstrate some of the points that are being argued?

Tony, those graphs are WHEEL output, so they are in line with the headline figures you've quoted.
I've re-read your first couple of posts - do you really mean what you say about the 2.5 low down torque delivery over a TS? Your later threads seem to return back to the normal TS rhetoric?

Paul - yup, its become turbo tantrums, but it was such an open question by the OP that its almost trolling - an amount of "discussion" and departure in different directions was sure to result.

Nick

 

Nick,
still those dont make sense, they look like 2 different rolling roads to start with, the second (JDM) graph shows 267bhp@wheels but only 159bhp/ton, where as the first (2.5) shows 259bhp 162bhp/ton, which straight away shows inconsistancies
On the rhs jdm graph, the faint red line is more in line with the torque delivery of the twin scroll unit, it is a shame i am not at home because if you actually saw what the standard (unmapped) car does, it will shock you a little

Tony

 

Hawkeye Sec C: Standard apart from Blitz backbox & intercooler. Running basic generic Uk fuel map with max bhp at 1.3bar, running rich. No other mods at the momemt.

So almost straight out of the box pretty good graph on a 2 litre. Next month to fit H&S decat system; 3 port; K&N; remap to peak 1.6 bar should see 370 bhp max.

 

This is what I stated in one my of posts in this thread. I have no doubt with the drive a 2.5 produces that it is the better road car, producing torque very easily allowing for quick and effective overtaking. My brother has a Dreamscience reflashed Focus ST which 'should' now be producing around 265bhp, but it's the increase in torque production that has really helped. They're torquey motors anyway but now cars can be overtaken with complete ease without ever getting into silly revs, not that it's like to rev anyway. It runs out of puff very quickly from around 5,750rpm onwards.

As I've also stated previously it all depends what drive you're also after that depends on what you see as your preferred choice of engine. I came from world of Honda VTEC's before my first Scoob so I'm used to a driving style in which I have to 'work' the car and gears in order to really be moving. But even short shifting in my Spec C at around 6,000rpm allows for a car that covers the local B roads devastatingly quickly.

I have no doubt that the 2.5 is a great engine with great manners. The point I have tried to argue is that from a pure technical/engineering viewpoint, the JDM is the better and stronger design of the two.

 

Exactly

 

2.5 is awful I hate mine:



Please someone tell me where this loses to a 2.0L