Yeah it is ported. Andy Forrest told me all his 20G's are ported unless otherwise requested.

A few people have mentioned to me that this could be an issue.

 

My 20g i got off a member on here, with just over 1000 road miles on it, he brought it new from andy f (new turbo, not reconditioned)

his car was a 2.5, and mine is a 2.0.

I think it has been mentioned to me before, that it could have porting for a 2.5 on the exhaust side, as my boost droops abit at the top end.

here are some graphs

 

I think this could be a very likey cause of the boost drop i'm suffering then.

It would explain why nobody can find anything wrong with the car.

Question is,do I do anything about it or leave it as it is now

 

it is a very quick car Simon I would leave it.. the boost drop will also be reducing stress on the engine at higher rpm.

 

I know that's the right thing to do but it's just that niggling feeling that there's a little bit more to be had out of it !

I noticed today that the coolant temperature runs alot lower with the Zerosports thermostat. Before it ran around 86 degrees cruising on the motorway and now its around 76-78 degrees

I think i'll get it up the 1/4 mile and see what it does next

 

zerosports stats work very well yes

 

is your boost drop the same as mine?

 

I am not sure that any TD05-06 20 G would be ported any differently for a 2 litre than it would be for a 2.5 or vice versa and any porting would not be the reason for boost dropping off.
Always fit the biggest air filter you can in the space available. The 57-0319 is not on my product list.. Is it part of a 57i induction kit.
Changing to a large filter is relatively inexpensive but it has to be as big as the space will allow.
On H13 I have 422 bhp and 360 ft lbs. 1.6 bar or marginally more. I need to find the graph. On P93 I have 409 bhp and 360 ft lbs. 1.5 bar. Little or no top end drop off.
If you were local I would be happy to put one of my turbos on your car for comparison.
Any photos of your filter set up.

 

Yes mate it looks very similar. Mine runs about 1.5 bar upto 6000rpm and then drops to 1.3 bar.

 

Hi Harvey,yes my filter is part of a 57i induction kit.

Here's a slightly older pic of it taken before fitting the new FMIC so just ignore the dodgy looking pipework



What do you think to this filter ? Could it be not allowing enough air flow at high rpm ?

 

There is a possibility that your problems could be related to your top entry layout. Have you considered converting to front entry which will give a much cleaner inlet tract ?

 

Yes that's something else that's been discussed but other people on here are running 20G's still on 90 degree inlet and don't have the boost drop issue. Not saying it's definately not the problem though.

 

Can you send me a photograph of the rest of your air inlet tract. I cannot see what happens in board from the joiner to the turbo.
The filter looks on the small side and may already be a restriction much over 320 bhp because I think that is what the 57i kit is intended for ie. a bolt on to the standard STi. I have looked again for this filter part number but cannot find it, probably because it is part of the 57i kit and the filter has another part number when it is on its own.
When originally hand built as one offs the TD05-06 20G was a genuine 380-420 bhp turbo and on methanol I saw Andy Forrest produced 442 bhp when we went over to Star, in Fife, one Friday afternoon. In more recent times I have seen some of these turbos producing much less power, 359 bhp, 364 bhp 368 bhp etc.
The 90 degree entry can produce as much power as the front entry but the air inlet tract to the turbo has to be done carefully and we actually experimented with this on both Jonny Gav's car and Alan Bell's peppermint green car from the turbo inlet we used a swept 56mm reducer which I think opened out to 64mm perhaps more and then plumbed in the MAF after that. It was possible to max out the green label MAF beyond about 390 bhp.
With photos of the rest of your inlet tract I may be able to make further comment.
harveysmith1@btopenworld.com if that is easier for the photos.
When was this turbo first bought?

 

Harvey - I've emailed you a few more pics

 

this si the info for a k&n filter that goes on the aps caik, from this how could you tell what sort of power it is good for?


APS CAI kit has K&N RU-3130 air filter rated at 800 CFM

 

340BHP-WRX. PM sent. No photos received.

DaOne :
[quote]this si the info for a k&n filter that goes on the aps caik, from this how could you tell what sort of power it is good for?


APS CAI kit has K&N RU-3130 air filter rated at 800 CFM


You are correct in that the APS kit runs the RU-3130 filter. This is a 309 bhp filter.
Did you not get an extensive e-mail I took the trouble to send to you, in an attempt to assist you gain more power?

 

I think i did, but can not find it now.


does anyone know what the biggest k&n filter i can fit into the space in the inner wing?

 

Ian : Some years ago I bought 5# APS FMIC kits in the mistaken belief they were amongst the best performing. The price was £1140 each.
Today the price may be in the £850-£1,000 bracket.
From my experience of the APS kit I will not buy or fit any more.
The APS kit I have is not as good at controlling ACTs as the Hybrid. Without me drawing attention to this Bob Rawle had already picked up on this during his mapping sessions. Others have made the same observation.
With an APS CAK I ran 417 bhp at a Southern Rolling Road Day some years ago. At the time no other Subaru had over 400 bhp. The RR Day was featured in one of the magazines. Loads of people were there and I still have the dyno plots. Dyno Dynamics. Chris Davies, the rolling road operator, an Australian with intimate knowledge of APS products suggested I change my induction.
I removed it and returned the next week on the Friday. 430 bhp. No other mods. Bob Rawle remapped the car on the Saturday and I went back to G-Force. 450 bhp. All for a change of induction and a remap. All runs at G-Force, Aylesbury within a ten day period.
This was not a freak result. When I investigated the matter further I discovered that the APS CAK was intended for semi standard STi5/6 of around 325 bhp max. The kit should not be fitted without rescaling the MAF Sensor, something APS denied at the time and clearly the kit was a restriction long before 400 bhp.
I hope this helps you.
e-mail would be far easier than P.M. harveysmith1@btopenworld.com
Regards,
Harvey.

To determine the maximum volume of air your engine will use, take the displacement in cubic inches and multiply by the maximum RPM you operate the engine at. If the engine is supercharged or turbocharged, divide the pounds of boost by 14.7, add 1 to this answer, and multiply this value by the CIDxRPM value. Divide by 3,456 for a 4 stroke engine, or 1,728 for a two stroke engine. This will calculate the maximum airflow required by the engine.

CFM= Cubic Inch displacement X Max RPM X Boost divided by 3.456 or 1728

To determine what volume of air a given filter is capable of flowing, multiply the diameter of the filter by its height, multiply by pi (3.14), and multiply by 6. If the filter is a tapered cone (different diameters at each end), add the diameter from the top and base together and divide by two for an average diameter. Here are some examples:


Round Straight filter:

CFM = dia. x height x 3.14 x 6

Round Tapered filter:

CFM = (dia. base + dia. top) x height x 3.14 x 6 divided by 2

 

thank you harvey, i remember now, have sent you a email

 

Harvey - Just tried emailing you some pics again