LOL @ Mark 450+ At the wheels ??

lol. I said 450 BHP (brake horsepower) because I thought it would make it clear that I'm referring to crank hp figures, not atw:lol:

I'm looking for 350+ hp at the wheels, but that includes a 2.4 stroker kit and a 50+ shot of nitrous. Also, that's American horsepower, and as everyone knows, our horses are considerably smaller here, so its more like 325 hp over in the UK!:lol:

Annointed,

Just wondered, because you guys normally talk ATW's bhp., and I didn't know if your 310bhp was ATW's or the crank.

Mark.

I'm still trying to figure out exactly what I have on my car. I think it's this http://www.takakaira.co.jp/php/template.php3?cat=2&id=104 , certainly all the bits look rather familiar :) Seems to go reasonably well, made just over 300 BHP @ crank with 16 PSI of boost on a UK spec engine. Sounds interesting at 1 bar, positively demonic at 1.5 bar :D Hmm, now 600 CFM, that should be good for about 400 BHP, I wonder :D ;)

Unless I've been living in la-la land for all my life, brake horsepower always means hp at the crank. Maybe the term isn't as well known as I thought, as I've traditionally used it when I'm refering to flywheel hp, whereas I say ATW when refering to at the wheels...ah, well, as the Aussies say, "No worries, mate!":D

How do we get rid of the 90 degree Bend

Dfullerton, you should post that as a new topic in the general discussion forum, so more people will see it. I'm sure its been discussed somewhere, but with no search, previous discussions are next to impossible to find...in fact, I'm going to go start the thread now, because I want to be subscribed to it!:D

Ok, i thought that i had got the hang of it but i think ive lost it again :)

This isnt going to be very technical so here goes....

Why does the td04 lose boost up the top end? If the exhaust gasses are spinning a turbine and equally spinning the cold air turbine building up pressure doesnt the exhaust gasses increase with revs? If so why does it appear to slow down and decrease boost. Or is the best air flow/pressure at say 3000rpm ish? If it is i see how the smaller housing has the impact it does and the larger housing can hold it. See i cant get my head around why if the exhaust gasses dont increase why it wouldnt maintain the boost it was at at 3000 rpm if not have more? can someone please explain cos ive obviously not quite got the hang of this.

Cheers.

Paul.

Paul,

It's a physical geometry thing. If you consider that ALL the air has to go through the hole in the front of the comressor cover then as the revs rise, so does the amount of air. This can only really be accomplished by increasing the RPM of the compressor (unless you alter the pressure ratio). You can continue to increase the the speed until the compressor tips are about to go supersonic, at which point the compressor can flow no more air, and you reach the choke line on the compressor map. Any attempt to go faster will almost certainly result in the destruction of the compressor. And that, as they say, is that. Well. Just about.

There is one other trick you can try. A given compressor is able to flow a greater amount of air as the pressure ratio is reduced. But rather than running less boost, you can increase the pressure at the inducer. This could be accomplished by ram effect, the high pressure air at the front of the car (radiator area) could be ducted and positively pressurise the intake system thus increasing the intake pressure into the turbo thus allowing it to run at a lower pressure ratio and thus it is able to flow more air. Prodrive used this type of setup on the at least the 2000 WRC, I think it may have been used on the 1999 WRC as well. Fussy lot, as if the RHF55 cover wasn't man enough for the job ;) ;)

Cheers,

Pat.

Pat,

thank you for that explanation, i understand, i think... So with a bigger exhaust housing u can flow enough air to spin the turbine enough to keep the cold air pressure more constant against the added extra input air. That does answer my question thanks.

Regards

Paul.

Esiest way for me to understand it all is to also see the turbo as a restriction to the exhaust gases flowing out of engine - swapping a td04 to vf23 you really do notice an increase in torque off-boost that can only be down to this (slightly skewed by the fact you have another 500rpm to wait for the damned boost, of course :)).

Richard

Whilst the exhaust housing does have an effect on turbo performance, unless the turbo is using a commpressor wheel, capable of flowing enough air, you still won't be able to maintain boost to the redline.

At the boost levels we're talking about, the compressor side is more important, than the exhaust side. EG, just compare the various cars running 340bhp+ at PE.

Trout 346bhp 1.4bar (iirc) P20
Bob R. 343bhp 1.3 bar (") P20

Andy Tang 354bhp 1.25bar (") P18
Tim Whiteside 344bhp 1.25bar P18

The end results are VERY similar, but the P18 turbo's will have less lag, and be more responsive.

Now, if you were wanting to run much higher boost levels (1.5bar +) , you would certainly want to use a bigger exhaust housing, to reduce exhaust back pressure, but then you'd need to address the compressor side too.

Mark.

By comparison, does anyone have any figures for the HKS Garret BB Turbo? Its a big f**ker

stevie,

is it on here?

http://www.gcg.com.au/catalogue/Turbos%20-%20Ball%20Bearing/ball_bearing.html

theres some of the component specs on
http://www.psychotic-racing.com/forced.html

Paul,

I know you came out for a blat on the track with me at Donno on Sunday, and that Craner's scared you ;)

But I think that you need a demo on the Road to fully appreciate the way my car behaves in the real world (remember we had turned the wick down a bit on the turbo for track to avoid overboost).

Are you about much this week?

I DO NOT UNDERSTAND NOTHING!!!!!!!!!

If I want to run only 1.1-1.3bar turbo hoded pressure what is the bes turbo to fit.

The STI/IHI V34, V33 or the Mitsubishi T05. (I think that V34 is the best in this pressures because it starts early and have very good top end - what do you think?)

Please tell me that because I do not now what I am going to do.

Thank you.

PS: Some people tell me that the best turbos are IHI and now you are telling that are Mitsubishi????

Guys, you need to look at turbo's, boost, power from a different perspective.

1) what do I want to achieve in terms of power v drivability.

2) How much AIR do I need to achieve the target power. at a given RPM.

3) What turbo is best suited to achieve the required air flow, and drivability, at a boost level safe for my engine (relative).

The TD04 has a very small exhaust housing, much smaller than the P18, and it also has a very small compressor.

The only reason that a bigger exhaust housing will give you more power, is if it's too small, and creating too much back pressure in the first place.

Mark.

SOORY, SOORY, I make a mistake :)

The turbos are V24 and V23.

Thank you.

Tim,

just wanted to say thanks for meeting up today and apart from spending loads of time chatting about things letting me drive your car. It was very trusting of you.

Highlight was following you home and watching you pull away on the straight with me rocking backwards and forwards on my steering wheel to keep up.:D

One thing i'll say again is i was very impressed with your turbo's spool up. I can easily deal with that!

Downer on the night was realising that i need to buy more stuff to match your suspension.

Many thanks mate!

Paul.

What is the spec on Tim's car - specifically which turbo and it has a manifold as well? What point do you get 1 bar?

John,

:rolleyes:

:p

:D

i think marks smileys says it all, i'll let you do the digging.


but it spools up 1 bar at 3000 rpm and is very tasty indeed.

mail me if u want.

laters

paul

Sorry don't think I am thick and missed it earlier in the thread. I know it is a monster :) Paul please spill the beans (email as per profile) if it is one of those cars people like to keep the details of "subtle" :rolleyes: :p Sounds like a nice turbo :D

John,

The turbo is a hybrid.

i meant that i think Mark's smileys suggest that if you want to know the technical details you should speak to him. I am not under any impression that things are secret? I just dont want to spout my mouth off and be wrong. I think its safer if I leave it to the makers if they want to post the technical details on a bbs. It may not make sense to do so from a commercial point of view? dunno? dont want to put my foot in it anyway.

One thing that I think i can safely say is the driving experience. Tim's car has 1 bar of boost at 3000 rpm boosting to 1.25 very shortly after (WOT in 5th i think i tested it). It holds this all the way to the red line. You can ultimately feel the big difference at 5000 rpm. Which, for my needs, is exactly the compromise i would like to achieve. The turbo at no point dipped below 1.25bar.

As regards to air flow, I can only again refer you to mark but based on the rr figures and the driving feel it must be very good. The limitations of the turbo I am told are upto 1.8 bar. Following him in my car was where i really saw the difference. It just pulled away. Initally, i was suprised. Tims car felt faster but it didnt seem like an extra 70bhp + 40lbs/ft. When i look back i think this is because low down there isn't much in it. But at the higher speeds/longer gears it pulled away. In 5th i could do nothing but watch :(. No point changing back to 4th cos there is even less there.

I have to say that having drove Tims car I am going for this turbo simply because I know that it is driveable in town and slow speeds but will achieve the performance i want. I think it all boils down to what you want to achieve. Not sure if you are looking for the same compromises as me?

Tim does have ported headers and a el manifold i believe, perhaps hed like to comment on the full spec of his car?

Cheers

Paul.

Oh gawd what have I done :eek:

Paul, suspension wise, I had a chat with Mark last night and it seems that cheap starting point for you would be to fit the Eibach springs. The concencus is that the stock suspension set up is over damped and undersprung, hence your car feeling as firm as mine yet rolling around so much!

Re the spec of the car, well it is meant to be a sleeper ;)

But just once I'll put up a taster:

Basis: MY98 UK Turbo, with 81500 miles on it and piston slap from 60k miles...when most of the mods went on :rolleyes:

VF22 based Hybrid - ask Mark for a true spec if your interested ;) but let's just say it's safe for 1.8 bar, currently running 1.25 bar peak (from 3300 to 7200 red line) 1 bar delivered from 3000 revs.

Pat/Tim built Indcution kit (no maf sensor and a K&N filter on a 3" stainless pipe)

Possum Link ECU

HKS FMIC

HKS Headers and a stainless up pipe (MY01 decat up-pipe) all heat wrapped

440cc injectors and uprated fuel pump (was 96% idc without pump now 80% idc)

Scoobysport Downpipe (again wrapped) and HKS Hiper Exhaust system

ERL Aquamist Water Injection (plumbed in last saturday night jit for Donno!)

£7.69 Tim built oil breather bodgit

I ran 344 brake @ 6500 and 308 lbft @ 4000 last Novemeber at PE without water on straight Optimax. This wasn't a true peak as the turbo was still well on song and power rising when we hit the limiter so we had to lift off at 6500!

Since then the engines done another 15000 miles, I've fitted the Water Injection and replaced the up pipe when the old one split at Bedford. People who knew the car when it was dyno'd and now tell me that it feels stronger...which is nice :D

There are other mods like brakes and suspension, but I guess that's for another time...

I'll delete the power figures from this post in a couple of days for safety reasons :p

Tim,

If you're basing the "80%" IDC', from tha comment's I made on the way to Donno'....that was at 6000rpm, not MAX'.

Mark.

Thanks Tim. You have no idea what you have done but it will be wonderful :D No fuel pressure reg I see?

Doh, must do a data log to check the real idc's :rolleyes:

John, no reg...yet ;)

Right im off on me hols so wont be able to follow this anymore. Although i think its come to close anyway. I have decided to buy the turbo supplied by mark cos i liked what i saw. It was a case of compromise from the beginning and i like what i have seen of the evidence. It wont be the biggest of them out there but it'll drive just how i want it to be, i hope.

Just wanted to say thank you to all that have helped me in my learning experience and esp to mark/tim for their time and patience. John always a pleasure!

Regards

Paul

R19KET

my peak power comes at 1.3bar, or is it 1.295 ;):D

Trout :D