minor_threat

Good thread. I miss Greasemonkey.

GRIFF007

Bob

thanks for joining in, I for one welcome your technical input.

Incidentally, by your repeated ref to 'it works for us' - I do hope that you didnt take my original quote as sarcasm or whatever, I simply quoted Ol as 'proof positive' that it works for a top tuner - as credentials to prevent thread degenerating same way as other DV thread did recently.

I have the greatest respect for your joint reputations and can vouch for Ol being very generous with his time and a true gentleman in my dealings to date.

It is my intention at some stage to lift a UK STi to highest realistic performance levels (with broad friendly torque curve) using only s/w and external moderate cost breathing enhancements (along the line of your JDM venture) most likely using your services, directly or indirectly

cheers

David

Andy.F

Bob, you are wrong I'm afraid. Whilst I'm sure it 'works' of a sort, it could be better.
I have done the research I can assure you that on a GC8 there are CONSIDERABLE gains to be achieved by isolating the filter in either a cold air box fed from the wing/bumper or indeed sealing the filter in the inner wing area fed from the bumper.
You mention temps under cruise conditions, well thats fine if all you do is cruise but what about after town driving in traffic, or sitting in a queue at a 1/4 mile day for example, the underbonnet temps are way up.
With a filter in the wing, fed from the bumper then there is a constant cold air flow through the inside of the induction system (assuming engine running) this has a cooling effect on the whole system, if you heat lag (wrap) this system then it will always be cold and ready to produce maximum power anytime.
With an underbonnet filter the whole system heats up (from the inside out) and then takes considerable time to cool down once on the move.

However, don't take my word for it and please keep doing it your way.
It makes it easier for us to stay ahead, on and off the track

Andy

GRIFF007

Yikes - now I have fuelled (pun intended..) a civil war.....

Andy.F

lol. No just healthy discussion

SiHethers

And as anticipated, the rumble starts

GRIFF007

I hope so!

So to add a little OB to the flames - what would you propose as a sensible budget ultimate performance upgrade for UK Blob STi, with budget of c. £2k - what would be anticipated resultant torque and BHP? - Personally, whilst I seek more Scooby character and ideally a little turbo aural enhancement, I dont want it much more intrusive inside than a PPP

cheers

p.s I am sure there is a high level of latent interest in mods at this level on these widely available Scoobs

p.p.s. a chart of cost / performance & detailed mod route at various levels from sub £1k to £5k would be of great interest to all

Bob Rawle

Andy there is no need to be afraid, you are, after all entitled to an opinion, however I do disagree with you of course. Under bonnet temps shoot up the minute a rad fan turns on, nowt that can be done about that, traffic or no traffic.

Thanks for the lesson but my research was completed two years ago on this, I really have no need to do it all again.

Ideal intake temps are not cool as you can get, optimum is some way away from that.

Insulation is fine and doea a good job of delaying the onset of heat soak, however it does nothing more than that and. of course, retains whatever heat soak is incurred for a very prolonged period. Rather than rely on something doing a job, and risking it not, I prefer to know for sure what is happening and then map to it, bit like water injection or nitrous or CO2 cooling, great for as long as it works properly, when it doesn't look out. of course if your car is only going to run high power for 10-11 secs at a time then your suggestion would probably be very beneficial, I would say that at TOTB this year, during the Iceland car's high speed run charge temps rose from 30.1 degrees at launch to 35.5 at the terminal 171 mph speed, coolant temps dropped from 78 to 72.6. hardly demonstrating that the "wrong" set up is a problem I think. And that was using anti-lag to launch and on every gear shift.

This whole topic has been debated several times over the last few years, doing a search will find several informative threads so, at least on my part, this will not become a mega thread.

Dump valves need careful setting up when used with maf based systems, as mentioned I use a very hard setting with no problems, what settings you need can vary greatly, the GC8 factory bov is really too weak for most uprated use however if a car setup is susceptable to maf reversion it will go along way to damping it out at the behest of response. Thats why if I supply/install a forge bov i set them up individually to suit the car. Again to reiterate the GDB bov is not a bad item in itself and not worth changing on a whim.

cheers

bob

Andy.F

Perhaps afraid was the wrong word, worry may have been more appropriate....for your sanity !!


You cannot seriously expect me (or anyone?) to believe that hot air to the induction is a good thing ! If you have a cold air induction then you do not have the hot air killing power everytime the fans come on.


Exactly and if its the right type it will be of low mass and hence minimal heat inertia.


The idea of thermal insulation is to trap air between 2 different temperature areas, air has very low thermal energy, the retention of heat in the correct type of insulation is almost zero.


Cop out, lets get technical and discuss air density and the effects of hot v cold on compressor efficiency.

Andy

Pavlo

I would welcome some warm air in the winter, I would consider having a removeable sluece to get warm air to the filter in the current conditions, that I could alter in the summer to give good isolation.

In the height summer in town driving I was regularly seeing 55ºC under bonnet temps at the filter. It didn't get much better with a sustained moderate pace either. I often found the TB temp was lower than the filter temp in these conditions, and this was at 270hp power levels.

Paul

john banks

I found that the inlet air temperatures (either inside the pipe or or next to the cone surface) were nearer to ambient in mixed conditions with a wing mounted filter than an unshielded or fairly well shielded (but not airtight boxed) identical cone filter with a shorter inlet system. They showed dramatically less heatsoak in the wing (rad fan on or not), and what heatsoak there was recovered more quickly. I could not show a power difference either way that I could measure even for the first power run after cruise for a maxxed out iON P450 on my EJ257 on Optimax without additives for the underbonnet or wing filter, this running about 450 BHP. It would be very difficult to control the experiment properly for heatsoaked conditions, but given no power deficit and more consistent temps in the wing, this is where it stayed. Notably as well, the small supplied APS cone filter which had about 20000 miles of use and never cleaned, fairly cosmetically dirty having been in the inner wing all that time, was making no less power than the replacement fresh K&N of about twice the surface area. I was surprised by these results.

I also like the standard MY99/00 UK dump valve. Forge recirculating with a variety of springs and shims was causing big MAF reversions for me, and I notice no lag between gearchanges, but I'm not using an excessively sized turbo for the engine capacity for pleasant road use.

Andy.F

Would that be the small filter a 'top tuner' said was limited to 400bhp ?

Andy

john banks

Same, the one we also removed one night and drew power plots like tracing paper with it on/off. Hence moving the area of suspicion to the cast elbow, but that turned out not to be the case on my setup. Also handily gives comfortable MAF scaling with about 0.3V in reserve for running 450 BHP.

SiHethers

John,

I suspect in your case no difference was found because 1) you're not maxing out your ion turbo in terms of pressure ratios at any given airflow, so any drop in compressor efficiency from added restriction, or increase in IAT is more than compensated for by 2) your very efficient FMIC.

On my VF34, being worked to its choke point, on my standard MY99 TMIC, these little things can make quite a difference. Certainly as measured by my butt-dyno in any case

Simon

Andy.F

Si , assuming you are referring to the air filter here, I can assure you John was maxing out the TD05/06-20G at the time we tried the (restrictive ?) small filter removal. Certainly John had it running up to 406 bhp on the 2.0 at that time which is a bit more than the 'hot air' tuners seem to be achieving on the same turbo

Andy

The Fixer

Just as a note, I swapped out my APS cold air induction kit (newage STi8) for one of the RCM underbonnet units which directs the filter up near the turbo prior to it going on the dyno. It didnt work well for my car, power dropped considerably with this setup.

john banks

Simon, I've tried higher and higher boost profiles with every turbo/configuration I've had until the power curves converge towards a power limit. If you run a flat boost profile and tune the ignition optimally (I fix the AFR whilst keeping an eye on EGTs) then you can then sort out what boost curve you need to get the most out of it on a given octane. It can be easy to run too much boost and feel the increased torque and actually lose 20 BHP at the top because it can't support the ignition timing for the octane and mods you're using. However, when you then find the power limit for your setup, and change something and can't get any more, fairly safe to say you've not removed a significant bottleneck at that level. By far the biggest power influencer is the turbo choice, most of my turbos have been hybrids, in those I invariably seem to max out the turbine wheel/housing combo first I reckon. The restriction you get from the turbine side far outweighs restrictions from most intakes or exhausts - just consider the pressure drop across each restriction, you're probably dropping 30-40 PSI or more across your VF34 turbine wheel, a few PSI in the exhaust or intake at most.

SiHethers

So, I'm probably choking the turbine rather than the compressor then? Although my MAF voltage would tend to indicate I'm at the top-end of compressor flow too. This being the case why have many people not found the VF34 with its P18 housing to give significantly more power than the VF35 with P15. That would tend to indicate that neither the P15 or P18 housing is limiting at the the max flow of RHF55 compressor on 2.0L subarus? Or am I missing the boat here

Andy, I think I was still thinking about changing from the standard induction setup to "enter name of favourite cone filter provider here" induction kits rather than cone "A" to cone "B" to no cone, as my own experiments showed that doing this gained power on a maxed out td04 (so airflow couldn't have been higher than say 360ish CFM).

John and Andy, would you not agree that charge temps are the real thing to measure here as with an efficient IC changes in IAT may not make that much difference? Not that I have the ability to measure either

Simon

john banks

Your limits will probably be both sides of the turbo, I was referring to compressor heavy hybrids. MAF voltage tells you something about both sides of the turbo, not just the compressor. P18 housing appears to be "bigger" than a TD05H 7cm^2 housing, but the turbine wheel is a bit smaller IIRC.

Charge temperatures are interesting, compressor discharge temperature perhaps more so? The temperature and pressure (and therefore the density) of the air before the compressor are of great relevance when considering an inlet tract. Give the compressor a lower density and for a given manifold pressure you desire, you will work the compressor side harder, heating the air more, working the turbine harder to drive it as well, all reducing airflow through your engine.

I suppose you could argue that my identical filter in the wing doesn't make more power than under the bonnet because the pressure drop might be greater in the wing, in exchange for lower temperature, but then an unshielded bonnet filter didn't make noticeably less than a shielded one, but they were both tested once a lot of cold air had been flowing through the bonnet.

I was horrified to see the underbonnet filter temperature after the car had been sitting on a hot day after being driven and then stood for a while, it took several miles to come down. That put me off. It did improve with shielding, but was still nowhere near as high in the wing, and as I say quicker to recover.

It is clear that a car with a filter in any of these positions can do the business, it comes down to opinion rather than right or wrong.

EddScott

So without showing that this thread as progressed far over my head with every post

If my car has TEK2, K&N Panel and a de-cat exhaust and HKS SSQV. Would I get any benefit from fitting an APS cold air kit. My car is MY00 so theres the dreaded MAF to consider.

Or am I just admitting I'm sat here wearing nothing but a burbery thong?

edit - AND if I were to fit such a contraption, would it need remapping?

SiHethers

Edd

Fitting an APS cai would be of definate benefit, but would also definately need a remap, but then that would be of benefit over a tek2 in any case. You will easily find the limit of your td04 if you have that setup. Close to 300lbft should be possible in the midrange with 280bhp at the top (standard disclaimer regarding rolling road figures applies ). You may want to consider bolstering the fuelling with a pump and FPR also, but that should not be deemed essential if your standard equipment is in good working order.

John, I think you've hit the nail on the head there

Simon

Bob Rawle

Gents having just caught up with the thread and todays postings I would apologise in advance to the rest of you for the following, it is how I feel though.

Andy, two years ago when we first met I had you down as a man of integrity, its a pity that has all (apparantly) changed in recent months, I find it sad that someone with your knowledge and background chooses to behave in this way. I consider that you have made some of your post's personal, if I'm mistaken I will be glad to hear it.
I have no intent to post in this thread again, we all have knowledge, sometimes we share sometimes we don't, depends on what it is and how it will be used. I enjoy a good debate with anyone, especially when its good natured and bourne out of enthusiasm, this is not (from my perspective) now one of those debates though, and smilies don't hack it.

bob

Andy.F

If only you would get more technical Bob then we could have a decent discussion but you just post 'clues' such as "Ideal intake temps are not cool as you can get, optimum is some way away from that."
Thats not much help, just something to hide behind in my opinion. Indeed the ideal charge temp is not as cool as you can get but the ideal turbo inlet temp is. Thats what we are on about here.
I had no idea who the 'top tuners' were in this thread when it started so it can hardly be personal, I just disagree that putting a cone filter under the bonnet is conducive to maximising engine performance in all conditions.

Seems like the majority on this thread agree. Prodrive also appear to agree

Andy

Welloilbeefhooked

iTrader: (3)

Just found this thread and want to ask a very easy question about what has been said by AndyF? I think.

Are we saying that on part throttle, when cruising, that a standard oem DV can allow the boost to re-circ and cause overfuelling?

Would the symptoms be something like hunting around 70-80mph?

I get this all the time when on the motorway and was wondering if it was indeed damaging and if I could do with a DV (excuse my ignorance here) that opens at a set pressure, probably just above peak boost? Does this mean this type of valve has no vacuum to it?

Thanks for any answers.

Andy.F

No, you're ok with the OEM as it recirculates the air after the MAF meter and hence the fuel input remains correct.

Andy

Welloilbeefhooked

iTrader: (3)

Cheers, my minds at rest.

scoobymods

i had a VTA dump valve on my uk 98 and it was nothing but trouble.
last week or 2 i had proplems with it not making any more then 10psi of boost,
follow'd Andy-f's post on the thread and now it's fine i also refitted the oe dump valve.



cheer's scoobymods.

harvey

iTrader: (48)

Dump valves:
The impression has been given, quite wrongly, that Roger Clark Motorsport fit VTA dump valves as a matter of course. That has not been my first hand experience with any of their big power builds and I phoned Olly Clark earlier and asked if they were now fitting VTAs for some reason. His response was "We will fit what the customer wants. If he wants a VTA we will fit it but my first choice would be a Forge Recirc." I hope that clears up a misconception and as Bob already pointed out it may be that on a particular installation a version 4 DV was mistaken for a VTA.
Another point to remember is that the VTA requires far less effort to fit and hence less cost.
Bob has set up Forge recirc dump valves on at least three different cars I have been involved in and from memory he set my STi 6 Wagon somewhere around 1.5 bar. On that car he has set the recirc several times as the engine has evolved. He used a hand held pump and having watched him do this several times I too have such a pump along with a complete set of Forge springs and shims. This has allowed me to set up quite a few dump valves and it is handy for setting up WG actuators too. When I fitted the TD05-06 20G to the WRX Wagon I initially fitted a Forge VTA as a stop gap but had all sorts of surge problems. (Easily overcome and no critisism of the turbo that I am very happy with.) When I replaced it with a Forge recirc I was still experiencing difficulties and tried three spring combinations along with shims. Whatever had worked for me in the past was not applicable on this occasion and Andy F suggested I try a softer dump valve. I am now running successfully with a Seat Ibiza OE plastic recirc dump valve and it does the job well. It cost me nothing. Thanks Jonny Gav for passing it on. I was most surprised that such a soft dump valve did the job so while Bob works on hard settings that have stood me very well on my STi and several other cars without the slightest hint of any problem, Andy's approach is from a completely different direction and it certainly worked on the TD05-06 20G.

Cold Air : If Bob believes that some dedicated cold air system is not necessary or a high priority on New Age cars, then while I am surprised, I have every confidence in Bob's analytical assessment of the situation, to realise there will be a lot of reasoning and observations behind it. The fact that Halldors car started on the line at 31 degrees and clocked 171 mph at 35 degrees or whatever indicates that temperatures were under close observation. Bob has also spent many hours around Bruntingthorpe in Halldors car, Callum's, Daz's, Mark's (2.2), mine, etc. etc. so he has plenty to go on.
My own thoughts are that there must be definate benefits from getting cold air into the filter. This will help to keep the inlet tract temperatures down and perhaps limit turbo compressor rises. It must give the intercooler a better chance. My own logic is to keep the cold bits cold and the hot bits hot so I want a hot exhaust side, as cool a compressor and inlet manifold as possible and I want to limit heat soak and reduce the speed at which it can take place. In my opinion the best way to achieve that is to segregate an area between the engine and inner wing, insulated from engine, turbo and coolant heat and only able to breathe via the inner wing or through the gap between the bonnet and headlights.
When first fitted, the Hybrid intercooler on the WRX could be 6 degrees over ambient in the cruise whereas the APS on the STi was typically 2 degrees over. A lot of work has been done and the Hybrid now out performs the APS quite noticably. The same lessons can now be applied to the APS. Some very interesting things were discovered, good and bad, during the investigation but that could be a thread on its own, however, heat soak in standing traffic or even when parked up has been greatly slowed down and ambient induction temperatures are achieved very quickly once on the move again. All very interesting. Now whether any of this is applicable to New Age cars or has a big effect on performance, I do not know. Obviously there will be an optimum charge temperature and I assume it will be possible to get below that figure but I am very happy with the learning that has taken place and the substantial elimination of the temperature gradient when both static and on the move. I think Bob will have a good idea of the temperature perameters for optimum performance.
Remember what might be good for a drag car or track car maybe different to what we need for a daily driver. Another little point, the STi had intake temperature compensation and the WRX does not. I wish it did.

APS cold air kit : If you are running an MAF system, under no circumstance should you fit one without a rescaling / remap of your MAF. Almost three years ago, one cold February Sunday morning I fitted an APS CAK. This signalled the beginning of my odyssey into Subaru tuning. 11 miles later number 2 piston had picked up the bore. The filter is located in the inner wing attatched to a 90 degree cast elbow immediately before the MAF sensor. Obviously the air flow inside radius to outside radius has to vary considerably and this can greatly effect MAF readings.
At that time APS did not highlight with the kit, the need for a remap.
I have several other reasons to doubt the professionalism of APS.

Some people on here talk in riddles or hint at something and as I am not clairvoyant I am not sure if the discussion relating to filters is directed at my findings with the APS filter which is actually a small K+N cone and my subsequent improvements.
With the APS cold air kit, (Link ECU MAP based) I produced 417 bhp at Well Lane. A further visit resulted in a similar figure.
15th March 2003 I went to G-Force and produced 415.5 bhp in the same spec. After discussing my runs with Chris Davies I considered that it was possible that the air cleaner in the inner wing or the APS kit itself was a restriction. Bear in mind that Chris is Australian and had a lot of development experience with APS. I then spoke at some length with K+N who confirmed that the filter I had been using was not intended for 400bhp operation.
The following week I removed the APS CAK consisting of the filter, 90 degree cast bend and probably the MAF body and replaced it with a shorter straight filter assembly and blanked off an area between the engine and inner wing for the filter to breathe cold air. I returned to G-Force and produced 434.2 bhp and I must stress there were no other modifications. Chris commented that I appeared to have removed some restriction. Bob then remapped the car and on 11th April 2003 I returned to G-Force to produce 450.2 bhp. The only alteration from the previous visit was the remap. Fuel in all cases was Optimax + mapped for 1ml per litre NF.
I cannot remember exactly but one of these visits was an organised RR day.

I shared this information with others but it seems they were unable to replicate my progress. Maybe they were not moving enough air in the first place. I don't know and I am not really interested in debating it as I know what has and has not worked for me and what I want to do/am doing. I am simply reporting as accurately and honestly as I can what happened to/for me so that anybody reading this has balanced information and perhaps this will assist in their enlightenment.

Anyway. Happy Christmas everybody.

RoRu

Harvey,

What sort of work have you done on your hybrid kit to make it out perform the APS front mount? could you pm me with some ideas to make it more efficient before i go back to bob's to have the mapping finnished.

Andy.