5 Type R

should perhaps have written less peak boost.

sg72

Take it your running standard vf28 at moment.

sg72

5 type R

Reason I'm asking is that I think for your needs.

If you got a new Turbo you will need to Re map to suit.

I am running a VF34 on my 5 Type R ltd.
With ECUTEK mapped to suit.

Also have HKS FMIC.(No W/I as yet.See previous posts on this thread.)

AM achieving similar figures to your own at peak. Depends on rollers.

However Spool up is quicker with peak torque arriving much earlier ( he says tearing his hair out trying to find R/R figures).

Agree 1.4bar boost is very close to fuel cut at 1.428bar (21 PSI).

I'm also close at 1.38 ( DAWES controlled )
Therfore also would agree with previous VF34/35 for your requirements also(You won't need FMIC.)

5 Type R

Not getting any fuel cut and have overboosted to 1.55 on the odd occasion before tweeking Unichip map,

I really do think I need to get a FMIC as within a few minutes of a spirited run you can feel changes. Would like to control this more.

I will be getting the unichip remapped after the next set of mods , just need to work out what to get....

Which turbo , which FMIC and any fuelling issues?

darkblueturbo

I've just read through this whole thread again and when the time comes the VF35 will most definately be at the top of the list...!!

Andy.F

Surprised to see this thread still bobbing along after my hols

Just a few corrections to make


Originally posted by nom

If you only want 400bhp from it then there is no surge, the turbo will be pulling the full 1.3 bar required by approx 3300rpm when using Gruppe-s headers.
If you want to run 440+bhp then the boost must be ramped up over the next 1000rpm to circa 1.5 bar.
Due to the very high efficiency of the 20g compressor wheel is is not appropriate to compare its power/boost ratio to a compressor wheel which was not designed to run in the 20g compressor cover.
A hybrid compressor such as the old style Garrett will require more boost for the same airflow.
As far as I'm aware the garret hybrid has been unable to support the 440+ bhp flow capability of the mitsubishi designed 20g.


Originally posted by Rannoch

Early development turbo's did indeed have a cutback wheel in various degrees of trim. All current turbos do not have a cutback wheel.

Andy.

Trout

iTrader: (1)

Andy,

you're back and in the same form as ever!

As you are into small corrections - a couple of points...

I am not sure that any of the users or the vendor are claiming that it would...

...however it is designed to provide a low boost threshold and give high levels of boost low down with no surge. I think both Alan and I described from our experience that it is a good, highly responsive turbo 'overall' and capable of around 400bhp at relatively low boost. I think we also both said that the 20G installation probably gave better ultimate performance.

I see that you have overcome the surge issues on yours - which is excellent - however I am surprised that you are not getting 1.5bar until 4,300 (indeed I am also confused by the way you describe it). Your hybrid is easily capable of producing more boost lower down, maybe you don't need it

BTW - when you are running your 440bhp + - what fuel are you using - rumour abounds of methanol, octane boosters and water injection all being used to squeeze out those extra horses...

...is this true?

Keep up the good work

Rannoch

[Edited by Rannoch - 8/25/2003 8:48:53 AM]

Andy.F

Rannoch

You are confusing boost pressure with airflow again What level of torque are you achieving at 1.5 bar boost ?

Unlike your own car and AlanG's, my car does not have water injection fitted, no need for these 'sticking plasters' when you run with nice low exhaust back pressure

I have recently been using NF but previously used up to 5% methanol as it was (is) cheaper and just as effective in allowing a few degrees more timing

Andy

Trout

iTrader: (1)

Andy,

another small correction...

...my car is not currently running water injection.

In terms of sticking plaster - water injection is an excellent way of maintaining performance in sustained performance situations such as on track. And I will be refitting it for just such occasions.

Of course you make you views clear here that you do no agree - and that is your choice.

Shame that all the WRC teams and many racing teams running turbo cars disagree with you.

In terms of torque - I don't know - not been on the rollers - only a lot more than it was before.

Rannoch

R19KET

Andy,

Nice to see you back, hope you had a good holiday, and looking forward to the return of some "quality" BS

I think we need to get some perspective, when quoting figures for turbo's. It can be very misleading to just imply that "turbo A" will produce 400bhp @ 1.3bar, and 440bhp @ 1.5bar, if using a set of "brand X" headers.

I appreciate you may have achieved these figures on your car, but your post implies that anyone fitting the turbo, with Gruupe-s headers will achieve the same. Personally, I think you underestimate the impact of the time, effort, and knowledge, you have put into your own car.

I think it would also be interesting to know what power your car produces on standard 97RON, or Optimax, so that those people not wanting to run octane boosters, or 5% Methanol will know what they can expect from the turbo.

This is of course very important, but a specific size engine, can only consume a given amount of air, at a given boost pressure, at a given rpm. The main benifit of a big commpressor wheel, is that it does flow a lot of air, at a given boost level, and a lower boost pressure will generally produce lower intake temps. However, if this isn't matched to the engine capacity, you get surge, and to prevent it, you have to run less boost. You have explained this, when you say that you can't run 1.5bar until 4300rpm.

Compressor wheel design can have a massive impact on surge though, and you can have two compressor wheels, flowing a very similar amount of air, but where one will produce surge, and the other doesn't. So if the design of the wheel doesn't cause surge, you can run more boost, and therefore get more air into the engine.

Ultimately, I think the TD06 20G fill flow more air than the Garrett hybrid version, but then the Garrett hybrid version wasn't intended to compete against the TD06 20G for ultimate flow. It will allow you to run more boost low down, if you want to.

I think Alan Garrods results give a good idea of what it does. Alans figures of 391bhp @ 1.4bar, with the car only partly re-mapped, and on standard pump fuel, are very respectable, and on the road, it makes for a very quick car, I believe even quicker than you were expecting !

It's not a case of one turbo is better than the other, it's a case of picking the best turbo to suit the owner, whether it's a 20 G, Garrett hybrib, VF35, or whatever !!!

Mark.

Andy.F

Mark

Are you forgetting the effects of EGBP on airflow ? This is generated by the extra work required to spin a less efficient compressor and directly effects torque. Example - a td04 will run 1.5 bar easily but will struggle to achieve 300lb-ft

Rannoch

I didn't say you and alan were USING water injection Also did you miss the after the sticking plaster comment ?

Geez, you guys must have been gagging for a wind up, you're biting well

Andy

[Edited by Andy.F - 8/25/2003 12:38:21 PM]

sg72

Andy!

Nice to hear you back.YHM.

Andy.F

Mark

You are correct, I was impressed with Alans car......until his turbo failed yet again

Andy

nom

Not very convinced that a compressor makes much of a difference to the EGPB. Certainly not a compressor that is purely 'less efficient' based on the fact that it seems to be matched correctly to the engine? Also, isn't there less efficiency overall with the 20G wheel simply from the fact that the wastegate needs to be open prematurely to prevent the surge, lobbing perfectly good (and typically really rather useful) exhaust energy 'down the spout'?
The 20G does seem a very efficient wheel, but so is one inside a 747 engine but you probably wouldn't want to try to run it on a 2.0l (well, some might ).
I've never hacked a turbo about, only know the theory (& the practical outcome ), so am probably talking bo11ocks anyway . Please add a pinch of salt...

Andy.F

Nice one nom Perhaps you would like to consider why the 20g compressor wheel can make some 70 bhp more than the OEM 16g wheel ? (which was matched correctly to the engine by Subaru )
It's not just peak flow capacity, my td05 front entry with OEM 16g compressor made 350 lb-ft of torque at 1.8 bar in the midrange. The 20g made 381 lb-ft at 1.47 bar at the same rpm and held over 360lb-ft from 4300 through to 6500 rpm.

Andy

T-uk

It can be very misleading to just imply that "turbo A" will produce 400bhp @ 1.3bar, and 440bhp @ 1.5bar, if using a set of "brand X" headers.

have to agree with mark here as those figures where at star , so will probably be higher down south

nom

Well, yeah; stick on a bigger compressor wheel & you can get loads of extra power, further & further up the rpm, needing more & more & more 'cutting back' from surge lower down & making it - to me - steadily less & less efficient for a car, although theoretically better & better for a boat engine . But I'd have thought that isn't quite what we're aiming at here? .
And Subaru wnet a little far with its decision on what the average driver wants anyway (ie 16g), shifting as it did to the little TD04 so hopefully no-one would even notice there was a turbo there at all
If you just want high power figures or want good quarter mile times & so on, a 'high rpm' compressor is probably great, but if you're after something for road use, I imagine it's manners aren't marvellous?
I think again we come round to there's no such thing as the right turbo, just a right turbo for the situation.

[Edited by nom - 8/25/2003 10:21:10 PM]

Fangoria

iTrader: (1)

Andy

You had mail............

Steve Mc

Andy.F

nom, with respect, you're missing the point !

If turbo 'A' makes 1.5 bar at 3000 rpm and turbo 'B' makes 1.3 bar at 3000 rpm, then depending on the turbo efficiency, turbo 'A' may be making more_or_less power than turbo 'B'

You CAN'T just say the 1.5 bar turbo is pulling harder/ better/ faster low down. It's all about efficiency. (have you noticed the key word here)

In the case of the 20g, John Banks done extensive testing on his std internals UK car and found that the 20g compressor was actually pulling harder from low rpm than the td04 or td05-16g !
With +ve boost from 2200rpm and over 1 bar from 3000 rpm the bigger turbo is not lacking in bottom end pull.
Remember that even 1.0 bar on the bigger turbo has been proven on a number of cars to make over 300 bhp It's certainly no 'drag race only' special !!

One of the reasons some of the latest Garrett GT series turbos are so successful is due to the exceptional efficiency of the compressor (over 80% on some units)

Andy

Andy.F

Steve

You may have been directed to 'junk mail' by my new filter (nothing personal ) Can you resend ?

cheers

Andy

R19KET

Andy,

No, I haven't forgotten about EGBP, or what causes it. Generally, it's caused by too much exhaust gas flow for the size of exhaust housing, or exhaust wheel. So, since the exhaust side of the 20G, and Garrett hybrid version are the same, higher EGBP's would imply higher exhaust flow !!!

You keep saying that the Garrett hybrid version is far less efficient, but Alan's 391bhp @ 1.4bar on standard pump fuel, and not fully re-mapped, doesn't indicate the disparities you are implying. I'm still interested to hear what your car would make, running like for like ?

Yes, Alan's turbo has had a thrust bearing fail. It's been replaced under warranty.

Mark.

Andy.F

Mark

I disagree !
If a compressor has a lower efficiency, then it requires more power to produce the same airflow as a compressor with a higher efficiency.
This motive power can only come from the exhaust gasses, this builds EGBP which saps power via 2 main routes.

1 - Increased pumping losses on the exhaust stroke.
2 - Dilution of fresh intake charge with burnt gasses.

This results in a vicious circle of increased boost required to pump in the same amount of charge air....increased EGBP...etc etc

I have had 2 runs on plain optimax and made 375 bhp @ 1.17bar and 395.5 bhp @ 1.35bar, I hadn't expected to run on the rollers that day as we were only meant to be testing JB's car (which made 406bhp).
I can post the RR print outs if you like ?

ps This was on the std ecu running 550's ie totally unmapped !

Andy




[Edited by Andy.F - 8/25/2003 11:22:24 PM]

Trout

iTrader: (1)

Andy,



PS Pedantically you are correct - although not what I am sure your avid readership understood - but also incorrect as my water injection wasn't even fitted either - it is all on a box in my office

Andy.F

So your car was running quite light for Elvington then Rannoch

Trout

iTrader: (1)

ROTFLMAO...

...ok, ok so it was nearly back to its standard weight. However your Scottish kgs are heavier than our English ones...your estimate of 35kgs difference between our cars is interesting as Harvey posted that your car weighed 1260kgs IIRC with you, your head AND half a tank of fuel in it .

So, again pedantically correct - but there again that would be without my fat **** and some fuel in mine to make it go

Andy.F

Cool !

Our KG's are heavier, our BHP's are smaller, our fuel is higher octane, our 1/4 miles are shorter (and downhill) our turbo's are laggier...........
I guess our tyres must be grippier and our cars more streamlined then further to the Elvington results

Trout

iTrader: (1)

You got it in one

Mind you when my engine is on the bench dyno I'll be measuring it in the same Shetlands that you use

...anyway, back on topic...tek tae me aboot turrbos...as the glove puppet would say!

Andy.F

Why ? Don't you have Mark sitting on your knee tonight

nom

No, Andy - I do know what you mean! For, say, 1.2 bar, the more efficient compressor wheel (say, 'a'), is the one flowing more air at one particular (engine) rpm. Yep. No problems there.
The clincher comes when compressor wheel 'a' cannot run at that boost at that rpm (surge), but compressor wheel 'b' can. Then even if 'b' is less efficient, it's producing more power at that rpm, i.e. low down. That's the point I was trying to make.
I think .
Looking at it the other way round, if at 3,000rpm 'a' can only make 1 bar but that 1 bar has more flow than the 1.2 bar 'b' can make at 3,000 rpm, this is a good thing! But I am not at all sure that this is the case? I don't have access to either of the compressor maps that are under discussion (or I think are under discussion? confused now! ) so can't actually comment here - not sure very many people can, actually, seeming how carefully Garrett guard most of their compressor maps!

David_Wallis

LMFAO @ Rannoch