P20SPD

iTrader: (1)

<moderators hat off>

Just reading that post T-uk with the link above, this one, dont quite understand what you mean.

It seems to me, nothing but praise

I changed the exhaust on mine last week, for the HKS Hiper all the way through. I then took David Wallis out in the car, just ask him what he said about it in 2nd and 3rd, forget 4th or 5th as road was ending and there were police officers ahead.

Now I do not profess to know the inside out of a turbo, and dont frankly care TBH, so long as it suits my car for what I want then i dont GAF(work it out)

<moderators hat back on>

I personally do not understand what you are all up to, but i dont like it, especially when you post links that praise a turbo, but then harp on about how good the TD05 is compared to some of the VF series.

Steven

john banks

T-uk was trying to tell me all along that he thought the MD304 was too laggy and the torque came in too high up to be a really good road turbo. I thought that the lag and boost threshold were what you needed to accept to run this level of power as I had not known better. After the point where I posted what I did, I tried to push further with the MD304 and floundered. At New Year when I tried T-uk's TD05 this theory was blown out the water. If you try them back to back on the same car on the same day you will see how marked the driveability difference is, the MD304 suddenly looks like a VERY poor relation.

T-uk

steven,

the turbo was good until mark told us it was only a 350bhp turbo,the lag and low down performance is IMO ridiculous if that is all it can do.

I personally do not understand what you are all up to ,I think the point that you are missing is that there is an alternative,better suited to the scoob engine,for much less.how can there be a problem with stating this.

[Edited by T-uk - 2/13/2003 10:46:09 PM]

Trout...

Paul,

the reported results from the TD05 are clearly very good - however I believe - and I can't find the posts - that 'some' people have had a problem with surge by getting the turbo spool up at relatively low rpm.

Whether this is a material problem is of course open to debate by those who understand turbo stresses better than myself. This can of course be resolved with good boost control - however then you will not make quite such good gains in the low rpm area.

Perhaps John or Andy can share their experiences in this area.

T-UK,

I really am uncertain as to what your point is. My earlier post was with regard to being sure that if you run significantly higher boost than the ECU or fueling system was designed for - that you should be careful to ensure that the car is able to deal with it and so avoid det.

John, Andy and others are being pioneering - and are prepared to test to the limits - which is why I thought the earlier thread was relevant. Others, who are not as well informed, may not be aware of this risk - stick on a turbo of whatever source, run 1.7bar, and then lose a piston or worse. I think it is a reasonable and objective comment - and nothing to do with whether a TD05 is great or crap - I didn't comment on the type of turbo at all.

However as you have specifically asked about back pressure and the VF housing.....I believe there are a number of cars with VF type P20 exhaust housings running well over 400bhp - so I do not think that the exhaust housing is an issue.

In terms of your comment regarding the VF 'thump in the back' - that is true of many VF turbos. However appropriate matching of parts, maps and engines can help there.

I have been in an STi8 that is producing around 350bhp (RR proven) that pulls 1bar from below 3,000rpm and spools up so quickly there is no discernable lag. The low down torque is very surprising, especially having driven some PPP'd STi7s that were gutless below 4,000rpm. That is with the standard turbo with remapped boost control using the Ecutek - and a comparitively tiny P15 housing. This car was prepared by a very, very serious tuning outfit in the UK that don't normally do retail business (and my only link to this car is that a friend bought it and asked me if I fancied a drive )

Oh, and finally, on my car - there is no obvious point that the turbo comes in, as many passengers have noted. They comment that is does not feel as quick as my older VF turbo - but strangely as the boost builds from 2,400rpm and the car simply develops smooth power - it is nearly a second quicker over the standing quarter.

However, because I like this performance (for the moment) it does not mean that I dislike the TD05 - nor have I commented as such. Hence my comments that I genuinely do not understand the intent of your posts.

Trout

PS John - do you have any idea what your terminal speeds were?

[Edited by Trout - 2/13/2003 11:24:21 PM]

T-uk

trout,

we both know how we ended up talking about vf/hybrids ,the editing has probably made it hard for others to follow though.

there is no point in me going on about this,I feel that my last post above gives my reason.

scoobynet is all about opinions,the link to that other thread was to show that they are allowed to change.perhaps as more change from vf/hybrids to td05's people will understand what I mean.

I agree fully about running high boost.it was only really the whatever turbo you choose to run at that level comment I questioned,IMO it does matter. I think all scoobs,even the standard ones need monitoring. but that is for another thread

carlos_hiraoka

John, just to "know" a little more about the TD05's ..... are you running it without a BOV ????? .....

john banks

With a BOV. Forge recirc red spring.

It is surge free on my car if I bring in 1.25 bar at 3000 RPM, rising smoothly to 1.67 bar at 4000 RPM. It does make very useful torque in this area as my plots show, even compared to a VF35 STi, or even a TD04. Have previously posted comparisons with MD304. If you can map the boost the surge is not a big issue on the TD05.

On the TD06 we need to experiment some more with various aspects of setup, after 4000 RPM you can do up to 1.6 to 1.8 bar (can't remember exactly where the map tops out), before then with more than 1.2 bar it surges.

Andy.F

Perhaps some clarification here. The P20 housing is a known performer when fitted with a garrett core but it's not really a VF turbo anymore !
I Agree that the P20 exhaust casting is not an issue. I do however think that the VF CHRA/turbine wheel is.

It would be great if you could post up a dyno plot or rolling road graph of a 400+ 'genuine VF' turbo's performance. Then we can all decide for ourselves with regard to spool up, lag and general power delivery.

There is a very interesting thread on MLR at the moment where different tuners dyno plots have been overlaid. It highlights just how misleading a peak power figure can be !

Andy

Absolute Shower

Being new to this turbo changing game...could anyone give a ruff comparison of VF turbo's again TD04, TD05's?

Eg, TD05 is about the same as a TD05 in max puff??

EMS

Andy,

what is "MLR"

Mark

Andy.F

Mitsubishi Lancer Register They had a day out at G force rolling road recently.

The thread -

http://www.lancerregister.com/bbs/sh...threadid=17233



[Edited by Andy.F - 2/14/2003 11:43:05 AM]

David_Wallis

cant find any overlaid ??

David

Andy.F

Check the revised link

R19KET

Andy,

Some of your comments are a little misleading.

The initial restictions on either the TD05, or the VF turbo's, are the compressor cover, and wheel. This applies to both.

At high boost levels, the exhaust wheels also become an issue, but this applies to both turbo's too.

I think a good example of this, is the fact that with your TD06 conversion, you were suffering from overboost, and boost creep.

You have solved this, to some extent, by clipping (cutting back) the exhaust wheel blades. This is common practice where a large compressor cover/wheel, is mated to a small exhaust housing, regardless of whether it be a TD, VF, or Garrett turbo, but you know that.

Now John is running high boost, he's having a similar problem, and no doubt, the angle grinder will be making another appearance

You also keep mentioning people who have tried in vane to achieve 400bhp, from a VF turbo. Please can you tell me who out of these people, actually bought a turbo, on the basis that it would achieve 400bhp ?

I totally agree about how misleading "peak" power figures can be.

Mark.

john banks

Wondering about a little clip on the FE TD05, possibly would help top end and make the little surge go away.

More worried about my gears than my engine... Mark YHM.

Absolute Shower

Mark...

Is 350+ not possible with most VF's then?? I was thinking of the VF30 and upto 350 bhp with lots of mods (exhaust/intercooler, etc)...with spool up being almost the same as a TD05...Is the TD05 better really?

Andy.F

Thanks for that Mark

I have never claimed anyone has bought a vf turbo and it hasn't made the 'expected' figures. There are many out there that are pleased with their output. I have however had a number of people contacting me lately who are looking for a bit more, without sacrificing low down torque.

I believe the VF and TD series have different issues with their exhaust turbines. The TD being very efficient, running into light surge on a standard compressor and causing overboost and boost creep on a 20G hybrid. The VF hybrid being less efficient, causing difficulty in achieving top end boost without excessive exhaust gas pressure.

I'd rather have the first problem, a proper boost controller will easily sort that. The VF issue is more difficult, heavy duty actuators etc to hold the wastegate shut is not very good for the engine internal pressures and temperatures. As you are aware this will reduce the VE of the engine.


Andy

Absolute Shower

Andy F, this is telling me to buy the TD05 for sure...hmmm..is it always this difficult to decide?

carlos_hiraoka

if you really want low end torque, plus a nice peak HP figure, you could do it by buying two stock TD04's (cheaper than a used TD05) modify a "little" the exhaust manifold (a lot of DIY's that may help u also for little money ..... I guess ), and place the turbos as close as you can to the engine heads (ala Cosie, EVO) which will make the turbo very responsive ..... use some Samco hoses (again cheap) and you may even get away with MY 97/98/99/00 TMIC since they have two air inlets, and since each of the small TD04 will work at relative low boost not much intercooling will be needed ..... and VOILÁ there u go

Andy.F

Carlos

Not sure if you're 'avin a larf' or not ?? I think the 2 x TD04's having only 50% of the gas flow each, would be very laggy. Boost threshhold would be quite high I think. The 3.0 V6 Mitsubishi's use these as an upgrade on the twin turbo's IIRC 1 bar is around 3.2k rpm (on a 3.0 litre remember)

Absolute shower - If you tell us the exact spec of your engine and exactly what you want to achieve regards BHP and torque, then a clue as to how much you wish to spend........we may all hopefully agree on a suitable turbo for your needs

Andy

carlos_hiraoka

Andy, no matter how much u try (unless using antilag) a setup like the one of the EVO / COSIE were the turbo is close and I mean very close to the engine head, will make turbos to spool much quicker than the setup of the WRX.
You will often see EVO's using their stock TD05 turbo producing peak torque before 3500rpm and producing more than 1 bar of boost before 2.8k rpm wihtout surge problems.
That is why I simply suggested this idea, if you could get the TD04's "close enough" to the engine heads ..... boost could be built quite early, and even on a 2.0L engine it "might" work

carlos_hiraoka

BTW I have already found a turbo that suits my needs .... just looking for a gearbox that can get along with it

Andy.F

Guess there's only one way to find out !!
I wasn't happy doing it as there may be severe reversion in one cylinder due to the uneven firing sequence during the exhaust overlap between cylinders 1&3 and 2&4.

If the firing order had been 180 degrees apart on each bank ie 1234 I would have done it by now !!

carlos_hiraoka

guess it is time to ask PAT ..... !!!!!

R19KET

Andy,

So what you're saying, is that people are achieving what they bought the turbo to do, but failing to achieve something that they didn't intend it to in the first place

Mark.

Bob Rawle

Andy, if you connected them a la MY03 twin turbo header system then maybe that wouldn't be so much of a problem ? ... as a thought.

My last version of VF hybrid made 400 ish, just wouldn't make the 450 ish I was looking for so I changed it.

The TD05 is a great turbo, I used one for nearly 60,000 miles and it gave me great results on a 9:1 compression engine, like anything it has its limitations, enthusiasm for ones latest toy is always overwelming if you have the toy. I think that some realism is needed when considering a turbo and that mostly stems from your car spec, what you intend to do with it and what you want from it.

cheers

R.B

Bob of the subject, have you got a forge rec Dv at your place ,if so we can stick one on tommorow.

Cheers

Rich

Bob Rawle

Hi Rich, yes plenty here, no problem to do at all.

cheers

see you in the morning.

carlos_hiraoka

Bob do you use a BOV with your TD05 ?

Andy.F

Mark I think we agree on that point.

The VF even in hybrid form appears to be flat out to get close to 400bhp, the TD05 will match that with its standard compressor wheel. Fit a bigger compressor to the TD and it will be pushing past 450bhp.
The whole point of my input on this thread is to try and get across the point that the TD has a turbine which is more efficient and better suited as a motive force for a turbo in the 350 - 450 bhp power range.


Carlos

Are you trying to get someone to say that you can safely run a TD05 without a DV but try that with a VF and it will fail ?