Pavlo

Thanks Andy,

My current list of performance mods is quite small

SS DP (2.5" join)
SS BB (2.5" pipe)
(standard mid section)
ITG panel filter
FCD
Boost frigger valve (until I work out something better, like a remap or dawes).

Not forgetting that the legacy has an okay chargecooler as standard, and I would say it's looks like being as good as an sti TMIC as standard, although I will be setting up some thermocouples to measure stuff soon.

So I am looking at what's next and here's the list:

Improve chargecooler; water wetter, pump
Improve induction, home made pipework (want something doing properly....)
ECU remap (home brewed lo cost)
Fuel pump
Decat centre (2.5" as I can't live with 3" system noise)
Adjustable FPR, rework ECU to suit.

Edited to add:
Up-pipe
Something with the headers/turbo housing

Paul






[Edited by Pavlo - 7/5/2002 10:08:01 AM]

GavinP

Pavlo,

I would think your setup is fairly similar to mine:

94 WRX (9.0:1) compression)
Legacy chargecooler (uprated pump/radiator/reservoir)
MRT 3" downpipe with high-flow cat
MRT 3" centre section with silencer/resonator
Remus backbox
Green "Twister" (cased cone) filter with ducting from front of car
Dawes device with standard size bleed hole
Link ECU (controlling ignition/fuelling)
TD04H turbo with 90 degree inlet


Fitting the exhaust helped spool up, the Link ECU did to a similar extent but the Dawes increased spool up by the greatest amount.

Although a lot of people use the Dawes to change boost levels, when I bought mine, it was to try and improve the boost curve : http://www.scoobynet.co.uk/bbs/threa...ThreadID=29594

Worth a try ?

Thanks

Gavin

[Edited to correct punctuation ]

[Edited by GavinP - 7/5/2002 12:26:35 PM]

Pavlo

Andy,

what RS parts did you use for your valve, as i am placing an order today.

And for the rest of you...

Would it be possible to use a Dawes in conjunction with the EBC element of an ecu?

I am thinking that the dawes could help spool up, in the region where the boost increases rapidly, and the ECU might have trouble keeping up.

Not sure of the plumbing as yet, but I would like it such that if the duty cycle was small (low boost or load) the dawes was pretty much out of the equation.

Just a thought, as optimising duty cycle for spool up on the ecu leads to over boost.

Paul

[Edited by Pavlo - 7/5/2002 1:39:35 PM]

Pavlo

the down pipe isn't a major factor in noise.

With the scoobysport dp I found an added tinnyness coming from under the car, combined with a kinda woooshh, and bit of wishhhh on overrun.

Best mod so far, but you will probably need to adjust the superchips bleed or you might get a major boost spike.

Hye, Mr Coops, what body shop do you run? Also, is your white legacy J*** HTP ?

Paul

[Edited by Pavlo - 7/5/2002 8:31:56 PM]

Pavlo

Primary for pre 97 engine...

Other than the down pipe, does anyone have any suggestions for better spool up, along with an estimation of improvement for any given mod.

EG, does an upipe give a perceivable improvement?

Paul

David_Wallis

uppipe, flow the standard headers.. Air filter, remove 90deg inlet off car... your running a legacy arent you?

Ecu Remap

David

Pavlo

Yes 94 legacy with IHI RHB5 VF12 turbo.

Thing is, what are the mods worth individually? I see people porting headers, then they realise that they matched fine, but the gasket is oversized. What does this mean?

As for front entry turbo, has anyone compared this to just a good induction setup with 90' entry? All the straight entry mods I have see have been combined with other things like induction kits, up-pipe replacement. What can a straight entry mod alone do for you? The 97-> cars have straight entry, but it wasn't like a magical fix for lag was it?

Some people will only run a panel filter, some people swear by an induction kit. Since i can correct fuelling, wouldn't an induction kit help?

Ignition advance also helps low down, the extra torque should mean more exhaust gas and better spooling.

All these mods are great, but I often see very general statements saying X is good, Y is bad, but they are backed up with bull arguements, or not at all.

Andy Forrest is the only guy that's put his cars performance where his mouth is, trouble is he's done everything, when maybe just a few of the mods would get you 90% of the way. I do however understand that it's very difficult to do minor mods one by one, when stripping the engine bay makes it economic to do as much as you can in one go.

I guess I am sick of seeing shullbit power figures, ultra high boost figures, and people saying 'you must have at least a VF22 to be making 300hp at the wheels'. Why is it that all these cars that allegedly have 400+ HP can only pull low 12's on the strip?

I realise the above comment might be constrewed to be aimed at contributor to other BBS's.

Rant over.

Now can someone please make my turbo spool quicker?!?!

Paul

dhorwich

a dawes device..!!

Dan

john banks

Andy makes lots of modifications and only seems to keep the ones that make him go faster. I am pretty convinced that virtually everything he has done to his car has been carefully assessed so he can get the best performance possible.

A 90 degree bend alone may not make a huge difference, but the sum of all the parts certainly does.

Pavlo

Exactly my point John re the bend. I think that leaving the std bend in place (and mine is bolted on, so front entry is quite easy) but using a carefully planed induction route, should be ery nearly as good.

With the bend in place, it's possible for that to be the only bend prior to the turbo. Front entry still needs a (larger radius) bend (in larger pipework = slower air). The WRC cars rotate the turbo about 30around the vertical axis so the front entry turbo connects almost directly to the airbox. While the turbo exit goes under the manifold to the FMIC.

Paul

Andy.F

I think what's also confusing is that you can make the same mods to two cars and get completely different results. An example of this would be the Uppipe, if you fitted a 52mm bore uppipe to an othewise standard car, it would probably lose power due to the velocity drop. Take a 350 bhp car and the uppipe is causing a substantial restriction, fitting the 52mm model equals considerable gains. The 90 degree inlet falls into this category, at standard boost, it just isn't a restriction.
For what it's worth, i've listed below the things I would do again (in order) and those I wouldn't bother with.
I am talking road use here, different for 1/4 mile racing but not many people into that.

3" Downpipe
3" system (no 2.5" joins)
Discard intake resonator and pipework
K&N cone filter in cold air box with large bore feed to turbo
Then and only then ! Dawes or similar
STi intercooler and twin inlet pipe
I/C water spray
Twin feed fuel lines
FCD
Uprated fuel pump
Port headers, fit uppipe.
Adjustable FPR
Straight entry to TD05


To get 'just short' of where I am now I'd leave out

Ceramic spacers
Chargecooler
Water injection
Exhaust wrap/blanket

nom

Does the 3" DP really make much of a difference over the 2.5"? Obviously there can be more flow, but aren't there restictions further up (down? Inlet direction anyway...) that make the increase very marginal? Or does the turbulence from the turbo, etc. make the difference?

Andy.F

Nom

This is another mod that only seems to work if you are breathing heavily already Initially it slowed my car when I was around 290bhp, don't ask me why

A 2.5" pipe will only flow 69% of a 3" pipe (difference in CSA) Some of the joins even on a 3" downpipe are 2.5" or less

I went through my whole system sleeving joins at 3" and fitting 3" bore silencers. It lets the exhaust gas expand more across the turbine, the net result is the wastegate opens more and creates less backpressure on the cylinders.

Andy

Pavlo

3" has got to be nice I agree.

I am looking for power levels in the 320 hp region, but with the focus on driveability.

The 3" pipe may have greater cross sectional area, but the pressure drop is going to be quite low on a 3/2.5" straight through system, low enough for me anyway. Diminishing returns and all that.

So I am now thinking that a dawes may really help the spool up, and that a decat centre and up-pipe will really help when the power levels are increased.

Disclaimer: Sarcasm ahead, please ignore if you just celebrated independance day.

Don't forget, that although my car is about 1450kg, because it's a boring estate, performance as seen by the observer is at least double that of any saloon. It's this effect that will ultimately make me faster than all of you!

Paul

Andy.F

Ah but it can only be REALLY fast of it's White

Would agree you should try a Dawes for spool up improvements, also found 3"/2.5" joins was fine for 320bhp

GavinP

Yep - spray it white - best performance improvement by far...

Thanks

Gavin

GavinP

Pavlo,

Using a Dawes (or any boost controller) takes control of the boost away from the ECU.

I have a Link ECU in my car which originally controlled boost as well as the ignition and fuelling but as the car is an auto, there were some BIG boost spikes during kick down.

Bob cured the overboost but said at the time that he had to alter the map and use a different restrictor to counter this which would reduce performance slightly.

With the Dawes fitted and the car remapped by Bob, the "counter measures" were not necessary due to the better boost control.

If I were you, I would fit a Dawes as a temporary measure to see if wastegate creep is a significant factor - if so, you may be able to adjust the wastegate to get a similar effect (and retain ECU control) which is better in the long term IMHO.

If you find the Dawes doesn't improve the situation, it then leaves you to look at the other things without having spent much.

Thanks

Gavin

FamousCoops

hey pavlo i think we have the same motor

a white 94 legacy saloon
80,000 miles
superchipped ,
boosting at 19 psi for 2 years now with no probs,
ramair induction kit
H&R uprated springs,
3" stainless exhaust from downpipe straight threw with only a 4" back box(no cat),
4 pot calipers and discs (from a my02)
braided black diamond hoses

and it goes on ,but i also am in the process of trying to decide what to do next the downpipe seems logical but my concern is the power to noise ratio does a decated downpipe increase the volume if so by how much?


[Edited by FamousCoops - 7/5/2002 8:00:47 PM]

[Edited by FamousCoops - 7/5/2002 8:02:27 PM]

FamousCoops

hi ,no it's an 'L' reg i get alot of the wooosh sound already lol

Pavlo

Nice, where did you get the lip on the front?

I assume you painted it yourself too...

The downpipe wooosh is different, it sounds a big like air being blown into a receiver. Difficult to describe, really. I went downpipe first, then back box the next day, still with standard centre.

I suspect the downpipe would make a bigger difference on yours as it's 3" beyond.

Mine is an estate, and I fully lined the spare wheel well with dynamat, and put foam sealing tape around the spare wheel cover. This dropped the noise in the car significantly, fine on the motorway at 70mph, I assume faster too.

Paul