john banks

Hi Mark, those results are good, but they are "only just" and on arguably more optimistic dynos? It doesn't sound like they are doing the MD321 justice from its on-paper spec which should be a 20G killer with this sort of flow with the ball bearing technology and large turbine, plus a compressor which flows at least as much. Presumably everything on it should outstrip an SR40 including the compressor cover?

Having said all that, we are making it sound like effortlessly sailing past 400 BHP is easy, and it is not. Everything has to be just right and it only take one thing to mess it up.

To get mine to do it I had to use silly boost, ridiculous amounts of octane booster. That might be because my cams and manifold were not up to the job, but who knows?

There are so many bits changed to get this far it is easy to get it wrong. I'm not sure 400+ BHP scoobs are common enough and understood enough yet to be sure of this result on the first attempt every time. It is a lot to ask out of a roadgoing 2.0!

[Edited by john banks - 11/19/2003 4:33:09 PM]

David_Wallis

Aus..

How do you know I know nothing about CFD and the theory behind it??

My Twin Up-pipe is nice..

ps..

see http://truegrid.com


ps I like APS..


[Edited by David_Wallis - 11/19/2003 4:29:21 PM]

Pavlo

so tempted...

The Fixer

Carlos, headers are next ~ on there own to see the real gain they give.

Paul, the APS spec is good out of the box but I believe they are suffering also with new age cars In that they have to use SR50 Turbos (50 LB/Min Air flow) to get mid 400's and thats with there 3.5 " downpipe.

Mark, if the turbo is 45/48 LB /min in real terms its losing alot or being very restricted in its current form.

John B, your comments about cars over 400 and the turbos they use, how many are classics and how many are new age? As far as I am aware my MD321 (with P20 housing rather than P18) is very close to Bob Rawles Turbo????

David, I like your up pipe as well

I know I will get to 400 if I put the headers on, maybe even the 3.5" downpipe and a bit of funny fuel but should I really need all this????

I'm still adamant there is a fundamental (restrictive)difference between classics, new age WRX and new age STi's

Could it be too much overlap on the AVCS? Mixture actually going down the exhaust rather than staying in the chamber?

Knew I should of kept my STi 5 lol






[Edited by RSVR Racer - 11/19/2003 5:42:58 PM]

Pavlo

if you think the avcs is causing problems, disconnect it

R19KET

John,

They may be optomistic compared to Star/PS, but far less so than WL. That said, Scott almost identical figures at PE, and PS ?

Neither Alan, or Jonno are running ridiculous amounts of boost, or octane booster, certainly not enough to make a 10% difference. On Alans car the same turbo can make 1.7bar + well before 4000rpm, so I'm not certain why it's so laggy on Conrads.

There would certainly appear to be something going on, because if we use Darrens car as an example, he's getting 404bhp using the same turbo and similar boost to Bob, who's claiming 495bhp ?

Mark.

The Fixer

Paul, if I disconnect The AVCS where does it sit, full retard on VVT or in the middle somwhere? What effect do you think it could have?

Mark, can't help wondering if there was a fundemental problem with the car before I started modifiying it?? Even on the standard VF35 it spooled up really slowly, to point where pulling out of junctions was risky without slipping the clutch..... Still, it's not making 1 bar until 4000 RPM and 1.5 until 4600 RPM On the road!

Conrad

carlos_hiraoka

now if you didn't spool up quickly the VF35 then you have a problem ..... VF 35 should make full boost in the very worst case at 3500rpm and 1 bar at 3000rpm on the road.

Carlos H.


[Edited by carlos_hiraoka - 11/19/2003 6:02:15 PM]

T-uk

headers will make it worse.

john banks

Agree Mark, it does sound like something is going on.

That sort of spool up was what Callum was getting on a similar turbo with a massive header leak.

If you disconnect the AVCS it sits at about zero degrees intake advance, or slips a degree or two at most. However, at peak power a lot of cars are running little or no intake advance anyway from what I recall of the maps.

The overlap you would be running on zero advance is 4 degrees on an STi 7 Type UK, and 19 degrees on the STi 5.

I don't know whether this overlap is based on contact or at a useful lift. So what appears to be an overlap may actually not be any significant overlap at all, but there is a difference between the STi 5 and STi 7 in this respect, at least the way the OEM ECUs are tuned at the top end.

[Edited by john banks - 11/19/2003 6:06:59 PM]

The Fixer

I will get the AVCS disconnected this weekend and try it, just to see what happens with the car and eliminate it from the problematic componant list, still

john banks

The more efficient larger turbo should be running low EGBP at the top end, so perhaps it could benefit from some more intake valve advance since reversion is not such an issue.

You may be able to check your map to see what intake advance it is running at peak power. If it is zero, turning the AVCS off probably won't help peak power and will just kill spool up and torque, and you may need to go the other way.

Just a thought.

The Fixer

John, what spool up & torque ? lol

Just read this on the APS exhaust system.

Errrrrrm....

The Fixer

Is there too much back pressure in this item?

Cast High Flow Turbo outlet

Conrad

Pavlo

How TF should we know? I'm serious.

Please stop panicing, you're unnerving me. I keep expecting the headline "399hp car enthusiast suicide attempt".

You're running round in circles like a headless chicken, and how many headless chicken do you know have got over 400hp?

Dude, relax.

Given the power levels people have acheived with what i would say are inferior exhaust systems, I would say the post turbo part is okay.

Although, is the system you have a "quiet" one? One with heavily baffled silencers, as Rich wild tried an MRT one and it lost him about 30hp. If it is a large bore, but restrictive one it may be worth trying something known good like an HKS hyper or similar, just to try. Ideally you need to blag stuff to try, or maybe there is another APS system that you can try with G-Force. It make be just something to as G-Force that has an easy answer.

In terms of power, the main differences between classic and new age are:

Inlet manifold design, branch length AND plenum.
TGV housings and turbulence plate
Possibly the head castings.
Ignition hardware, coils etc.

Everything else you have covered. An I would say the prime suspects are the inlet manifold and TGV housings IF there is a classic/new age difference at all. Longer inlet manifold branches will kill peak power, but raise low end. The TGV housings and plate make have an influence, it's an unknown, and possibly worth hacking them out if you don't mind.

Keep it simple.

Paul

EMS

The housings between the inlet manifold and heads are completely straight through on the Eurospec STi, no deflectors or whatsoever!

The head castings are simmilar (or the same).

Anyone thought about the cams? I think that will be the bottleneck. I have seen measurements from the inlet cam and that one was quite a bit "softer" than the "normal" WRX one! Check this: http://forums.nasioc.com/forums/showthread.php?s=&threadid=419230

Mark.

Pavlo

That is indeed interesting. Sti5 cams are 256 duration and 8.5ish (8.35 or 8.65) lift, and they make good power. I am surprised at the US wrx cams though.

It would also indicate that a STI RA spec C head is very good in terms of value, as th esprings should be all set up for the extra lift.

Paul

EMS

The non-STi US WRX is almost identical to "our" WRX. The ignition and fuel maps are identical, so I don't think the engine internals will be different.

I didn't know about the differences in cams between MY99/00 and after MY01! (that could be the explanation why I normally get more power out of the newer WRX with about the same setup....)

Mark.

David_Wallis

wonder if its anything to do with why rally teams use phase 1 manifold??

Possibly phase 1 heads or adaptor plate?

David

john banks

The UK STi 7 intake cams only have 0.1mm less lift than the STi 5 cams, and the same duration (242 according to the service book, but it is not clear what lift this is measured at), the AVCS adjustment range has the STi 5 timing not far off the middle of its adjustment range. Exhaust cams are identical.

The WRX intake cams have 1mm higher lift than the UK STi 7, and only 2 degrees shorter duration (240 degrees). Exhaust cams are 0.5mm extra lift, but 8 degrees shorter duration.

So I don't understand why without correct timing the UK STi 7 cam should be at any disadvantage to an STi 5 cam. Surely the AVCS could more than make up for 0.1mm less lift.

Andy.F

FWIW my cams only have 7.9mm lift

Andy

john banks

93-96 Turbo is listed as: (who knows if the RA is any different)?
Intake: 6 BTDC - 56 ABDC (242 duration)
Exhaust: 55 BBDC - 11 ATDC (246 duration)

Pavlo

It's worth noting, that the US WRX appears to have much smaller intake ports in the head castings. This would tie up with increased lift, as it should provide a better balance for te power band the car is trying to acheive.

Paul

john banks

In a NASIOC thread they split up the big and small port head castings - EMS confirmed the Euro STi 8 was small port - wondered which the STi 5 belonged to as this could be the real difference?

[Edited by john banks - 11/19/2003 10:35:02 PM]

john banks

Paul, are the STi 5 heads like this:


or like this:


EMS says the STi 8 UK/Euro heads are small port, so I suppose like the second picture?

Pavlo

uuuuuurrrrggghhhh!

NONONONONO!

Sti5 heads are like the former, nice and big.

Er, Houston, we have a problem...

Paul

Pavlo

john banks

EMS do you have any pictures of the Euro STi 8 heads to confirm? Is this the bottleneck we are looking for?

john banks

Anyone know about the ports on the MY99/00 UK/Euro?

Pavlo

V5/6 ports are the same for UK and Sti