Project STi Time Attack

[dynamix]

I thought I would do a copy and paste of a project thread I have had going over on BigPower - hopefully some of the issues that I have faced and solved may be of benefit to you here.

I apologise in advance for the length of it

I thought I would start a new project thread for my car to help me to prepare the car ready for Time Attack at the end of July up at Knockhill. If all goes to plan it should be almost ready for shakedown at Cadwell Park on the 16th July.

Issues:

1. Injector duty too high running at 95+% IDC at the moment even with 3.8 bar fuel pressure
2. Air restrictions caused by airbox
3. Oil throw issue on prolonged cornering causing catch can to fill within a few laps
4. Suspension needs to be lowered and reduction of body roll and allowing greater cornering speeds
5. Tyres ... I need some
6. Brakes
7. TA Specifics

Plan of Attack:

1. 800cc injectors are ready to be fitted along with adjustments to the mapping to suit and small increase of boost as we had to back it off to keep within 100% IDC. This should liberate the top end a little more where duty cycle issues really get highlighted. This will extend the available power range upwards slightly giving the option to hold a shorter gear through a section rather than short shifting prior to a corner.

Power-wise I would expect another 15-20 bhp from this in the peak region but more importantly give me IDC of 80% as a max.

2. APS 70mm inner-wing mounted induction kit arrives tomorrow and will get fitted before the injectors as it will be easier to adjust the MAF scaling first to suit this and then factor in higher flow injectors than the other way around. Aside from an increase in induction noise (which I personally dont like much) it will make the whole induction system flow better and should increase both torque and bhp figures a tad once mapped to suit

3. The Oil Throw issue needs solving as I do not want to be depositing oil onto the track for other competitors or for me to have a moment on. I have decided to go the whole hog this time and fit a 3 x inlet, 1 x breather and 1 drain 2.6 litre catch can from Roger Clark Motorsport. This will be aeroquipped to drain back any collected oil to the sump, thereby keeping the oil within the engine and not sprayed underneath my car Whereas 2.6 litres does seem excessively large, I am fed up with having to drain the catch can after half a dozen spirited laps.

The catch can does not catch hardly anything during normal road use even at high boost so can 100% be solved by this solution.

This is a photo of Bob Rawle's solution that I will be putting in place (although i will be using a banjo bolt rather than a straight feed):



4. Suspension - This is strangely a lower priority than the others but as my existing suspension seems to work ok enough as it stands, it would be great to make it better but not 100% essential if funds are limited. Shortlist at the moment is: EXE-TC and KW Variant 3.

5. Tyres - looking for a small supply of R rated, probably Yoko 048's 235/45/17 for my spare wheels (sponsors would be greatly appreciated on these )

6. Brakes - not really an issue now with the PF discs and pads but will be removing the backing plates and fitting cooling ducts to ensure that they stay as good as they can be.

7. TA specifics - I will need to go through the regs to ensure that the car will pass scrutineering.... be a bloody long way to go only to be turned away for a stupid thing


The end power result should be in the order of:

380 bhp
420 lb/ft

Not huge figures by the levels of some here, but with torque of over 350 lb/ft from 2800 to 5500rpm it should be pretty rapid around the track

[dynamix]

It will drain straight back to the sump allowing for a small delay to drain down the hose. It will burn off any water in there quite quickly and will effectively mean that rather than the oil coming into the intake (as is the std arrangement for emissions purposes) it will get recycled and keep the engine det free without me having to drain it or worry about whether it is full (as I have to at the moment)

Tyres:

Have pretty much decided on running Yokohama A048R 235/45/17 in a medium compound. These are slightly softer than the normal 48's so wont last quite as well but should heat up quickly and be warm enough on the hot laps to make it count and try and keep up with Mike

Hopefully they will last a few track days so that i get a chance to see how much different they are at Snetterton.

[dynamix]

Firstly the Roger Clark Motorsport Radiator Cooling Plate

Took all of 1 minute to fit and from what I can see from water temps might have reduced the temps but it is always difficult to tell. Looks pretty though.

Carbon is so last year



A close up on the badge...


Because of the weight gain that Gerry H pointed out I thought I ought to strip some weight to compensate. The underbonnet sound proofing was stripped (read ripped) off to bring it back to sqaure one. Who knows this might make the engine bay cooler aswell.

[dynamix]

New 1 litre AFFF extinguisher fitted today. Min std/size required for TA.

Previous dry powder extinguisher (1 Litre) is for sale

This time properly bolted to the floor rather than just self tappered and with restraining strap so that it wont come lose.



The final install:

[dynamix]

Well, I spent the day down at Mocom Racing making some changes that have been well needed.

The agenda for the day was:

1. remove standard airbox
2. fit APS 70mm Cold Air Induction Kit
3. adjust maps to compensate for the greater airflow
4. fit front splitter
5. fit 800 cc injectors
6. map again to suit these

Quite a lot .... so I got there bright and early at 9am armed with some milk and sugar and plenty of smokes ... this was going to be a squeeze to get all of this done in the time available before I needed to be home so Rachel could go out on the razz.

Zak set out to work straight away unbolting the standard airbox and trying to thread the needle that is the APS kit into the given hole in the inner wing so that the air intake is isolated away from hot engine temperatures.



This was a bit of a tight fit but Zak and Luke soon had this sussed by moving the ABS unit for a moment just so that they could twist the L shaped pipe into place and bolt it to the inner wing.

While they were busy, I was actually getting my hands dirty too by removing the fixing at the bottom of the bumper and marking holes to drill for the new front lip spoiler (from www.ScottLowe.co.uk - thanks Scott ) Then with more than a little fear I started to drill into the bodywork to allow for the supplied nuts and rubber expander nuts to slot through. Supposedly this is a 10 minute job, which I am sure it would be if the bolt were 1 mm longer. They werent



So... a bot of lateral thinking was needed and a piece of gravel

Now armed with a piece of gravel I could fit that into the end of the 8mm socket to enable me to push the bolt up at the same time as twisting ... worked a treat

Within a few minutes the splitter was now in place



At the same time, Zak had finished fitting the induction kit and we were ready to start mapping.





Well almost ready, firstly Zak has to turn the floor of my car into a mass of wiring, cables and det cans.



We even had a little helper trying to assist with bolting the necessary sensors and safety equipment.



Mapping was detailed and very time consuming as when the induction kit is put on (particularly one with a larger than OE diameter) the MAF reading are well out as the air flow is slower for a given voltage and in this case leaned the engine out by the order of around 30% in parts of the map - just shows how restrictive the std airbox can be at certain power levels.

The ECU std map allows for up to 300 grams/sec on my model for a given voltage through the sensor. With painstaking accuracy and attention to detail in ensuring that the curve was smooth and provided the right fuelling all the way up the range, Zak finally got this to scale to around 465 grams/sec - now I just need a turbo capable of pushing that much into the engine....

Previous to today, my injectors was maxxed out at 1.45 bar (see post 1) but now with the increased airflow, they were maxxing out at 1.2 bar and flowing more air than before too. Could this be right - same power less boost ? Doubting it, the maps were done and redone several times to get every last ounce of smoothness to them before calling it a day. We had taken a long time getting these spot on that the 3 hours to change the injectors and remap had been eaten into.

A few more tweaks later we were heading back to Mocom racing for a cup of coffee and to pack up for the day - and to arrange for me to go there again next friday to get the injectors done.

The results were astonishing, we had got the same power as before but with 0.25 bar less boost

This bodes extremely well for when we add the boost back in (and a little more ) next week. Maybe my guess of another 20bhp was a little conservative but whatever 0.25 bar works out to be it will certainly be fun

Car got back home after doing a quick dyno run to confirm our thoughts about the power - I havent fully compared the two but this one worked out at 297 whp but with a car full of tool kits and junk. I will do a proper comparison at the weekend without a full car.

[dynamix]

It is really hard to say what the limits of the internals are as there are not many that have pushed the std internals this far, but I am reliably informed:

- pistons will be okay for up to 500 if det free mapping
- rods will be okay for similar if not over revved
- liners will cope with 500 lb/ft

Everything I have done has been done so with an absolute paranoia about det - this, I am told, is what will kill the engine internals quicker with the 06 chocolate pistons.

THIS IS WHY I DATALOG

Having said that, If I took the view that the pistons, rods, rings, bearings need to be replaced in order to get near my target, that is a shed load of money - maybe 3k+. With a short engine being

[dynamix]

Woohoo - they've arrived

4 x Yokohama A048 235/45/17 in Medium Hard compound - decided that the MH would give me more wear/value for money than mediums and chasing the last 10th of a second would be beyond me at this stage.

Anywayy, there are here - just need to decide which rims to put them on

[dynamix]

Today was the day to solve the oil throw issue with the help of Gary and Chris from AP Tuning in Norwich

Having spoken to Gary and got all the Aeroquip parts on order they duly arrived with him yesterday and I rolled up bright and early at 9am today to get the new Roger Clark Motorsport catch can fitted along with the aeroquip gubbings in order for any oil collected from the cam and crankshaft breathers to return to the sump.

Alll would have been perfect if it wasnt for a school boy error on my behalf giving the wrong size for the drain outlet of the catch can - I had asked for -10AN where in fact it was -8AN. Heyho, we could do most of it and just add that fitting tomorrow.

As we we having to drain the sump, I thought I may aswell have a full service done at the same time, well almost a full service anyway as the gearbox oil had already recently been changed

So, Coolant was drained, Oil was drained and Brake fluid replaced and bled to remove the fluid that had been in there for a few track days and had probably seen better days.

Also on the list was to remove the backing plates from the front discs to help with brake cooling.

As Gary had experienced problems with smoking from his car yesterday on idle, he was busy carefully dismantling his engine whislt Chris worked in his normal very efficient and tidy manner to get the work done, whilst all the while giving me a commentary on what he was doing. I was also trying to assist where I could, with removing the intercooler (got this down to a fine art now) and refilling the oil and pumping the brake pedal fater the back plates were removed.



Once the breathers were cut to go from the two cam breathers and the single crank breather, it was ready for the catch can to be fitted. Chris was his usual deligent self and wouldnt settle for anything less than perfect siting and fitment - result was a good un nicely tucked away on the chassis leg and rock solid. So much easier to drill with a 90 degree angle air drill





I had also been asked by Gary for the length of the Aeroquip hose that I needed to fit to go from the catch can to the banjo on the sump - I said 50cm should do it to which he replied: "that will never be enough I would have though about 1.5m, but I will get 2 metres". ...... once cut it was 50 cm - I was chuffed

So now it was time to fit somthing really 'motorsport' to the car

It looks fabulous !! - the only shame is that no-one will ever see it. So I took some pics





The breather pipe from the can was then fed further down underneath the car to remove any possibility of any oil vapour from getting onto front brakes and strapped up out of the way.



We did have an appearance of my mystery knock which baffled us for a while. Sounds like Big End bearings are going but only happens at idle and goes away when above 2000 rpm and under load. To add to the mystery it is intermittent. Sometimes it will appear and you can switch the engine off and on again and it will be gone, other times it will not be there at all. Mostly it is only when cold starting.

A stethascope (i know it is spelt wrong but dont give a fcuk) was deployed to try and locate the offending article. It was somewhere in the region of the cam belt idler / tensioner but no noticeable play was present there, could also be the water pump or oil pump but neither has given me anything to doubt that they are running 100%.

We did think about changing the tensioner/idler until ringing Subaru for a price which was over

[dynamix]

I am very proud of myself today .... I just ....








changed the cambelt, cambelt tensioner and cam idler .... woohoo knocking has gone ... yes you read that right. I the man that cant change the oil without pebbledashing a workshop floor, really did pretty much dismantle the front of my car and change these things with my own fair hands. I have all the cuts and grazes to prove it I did have expert supervision of course just to make sure I didnt do anything totally stupid more than once

It seems I was living on borrowed time for the past year with that knocking - it could have gone at any time and killed my engine On removal the idler was the cause of the main problem with visible as well as audible play in the roller bearing, the tensioner had a small amount of play too so that was replaced as a precautionary measure.

Things didnt go all smoothly as planned as when torquing one bolt up to 29lb/ft (not much) it just wouldnt tighten to that much but kept turning... thinking something was up I handed Zak the socket and then click and the bolt had sheared in the block

Luckily there was a bit sticking out and whilst zak and I were preparing to drill the stubby end out of the block, Luke stepped up and unscrewed it with his fingers :pmsl: - phew what a relief and top bloke

Anyway, done now in just a few hours over what Subaru say it should take

Injectors will have to wait til next week now, but this is a massive relief and the difference in noise is superb ... it purrs now ove:

Thanks Gary @ APT for correctly saving me from that worry and potential very expensive problems. You really can walk on water sir :notworthy:

Also, nice to meet BeeSTi and Simon 57 down there - good chatting to you guys and hopefully you will share some of your tales on here and join us for some track action soon

[dynamix]

These arrived with Zak today for me from Alyn at ASP



Bigger injectors and fitting for these tomorrow and then we are all done.

Yokohama A048's got mounted on tyres today by my friends at Magnum Tyres in Haddenham - fantastic job, great service and great value too. Been running them on the road today and first impressions are .... loads of grip (even when not scrubbed in) but boy are they noisey. A real irritation whine at 60 mph


Soon goes above that though, so that is good

How good are EXE-TC ???




let me tell you .................. fekking awesome

Had the geometry redone aswell and now running:

Front :
2.25 degrees neg camber
5.5 caster
a touch a toe out

Rear 1 degree neg camber
a touch of toe out


Rails on Corners Goes is Like it round (rearrange these words)

Cheers Zak, Luke and Alyn at ASP for the hardware

Some pics:

Carbon Flaps



Exe-TC



new ride height

[dynamix]

Well, arrived at Mocom at 9.30 am ready for today's activities and have been home about 30 mins

The plan for the day was to change the injectors for newly modified higher flow to give more headroom to add back the boost (and hopefully more)

Some highs, some lows but the long and short of it is that the drive home was rather quick - the STI is proper quick now

Unfortunately despite some serious fettling, the turbo would not make any more than 1.1 bar top end so no pub figures here.

The more bad news was that in order to get bigger and better figures I would need to change to a bigger turbo..... I guess I have found where the limit of the VF43 is

However, we did get a good 1.5 + bar through the rest and an almost instant spool up so will be great on track and with injector duty cycle way way lower than it was leaving plenty of headroom

[dynamix]

Had a chance to get out today and despite the car frightening me with a CEL from a faulty Knock Sensor, all is now ready and the mild panic over. Thanks Ren for your help











Now to go and wrap it in cotton-wool

=================================

And that was the end of that story a new project to come soon

[danr55]

what a fantastic thread, and read.

keep us updated with more developments

[WR1 Bro]

Fanny tastic read fella. I've spent nearly an hour looking at the pics and reading what you have to say. Very interesting... looking forward to the next installment.

[Mac-1]

Fook, my head hurts.

Grate read, not to sure that I fully understand it all but I get the bones of it, we need to get the camera in for a few laps.

[dynamix]

Happy to answer questions but I am learning myself as I go along

[WR1 Bro]

Do you work for a living or do you just play with your car? Seems like it is a fairly time consuming passion for you?

What turbo are you considering?

[dynamix]

for a living I design and build websites. I work for myself from home so have always got a computer or 3 on

passion ... probably more of an obsession now according to the wife but she is very tolerant of me so long as there is money to eat, go on holiday and pay the mortgage etc

Turbo ... this is the next big thing and the seeds of 'need' have been sown in Rachel's mind on the basis of my lack of relative power at TA.

The options are either:

MD321T or FP Green

Both should be good for 450 + bhp and around 500 lb/ft torque but do present some other 'issues' such as the std pistons I am using at the moment being very marginal at that level and would probably not last long. I could de-tune the turbo and not use its full potential running it at 400bhp 450 lb/ft but that does seem like it would frustrate me on the basis of knowing what it is capable of or I could drop some forged pistons in.

I am investigating costs for this as we speak and will be the next project that I speak of.

The most likely result will be the MD321T with forged pistons alongside an Exedy organic Clutch. This should get me around 450 + bhp and 500 lb/ft with good reliability on pump fuel and a little more than that with a vpower / methanol mix for track days.

[presa900]

What a great read, keep us posted on developments, great to have you on the site

[Houdini]

Bilmey, Dunk!!!!!

That's a helluva good read. Lovely gaff too, by the way - I must get into web design work

It's fair to say I'm suitably in awe, and not a little envious of the animal you have as a 'daily driver'!

[WR1 Bro]

Is this a tempory fix to cover up the hole in the wing? Is it really important to cover this hole to stop the warm air coming from the engine bay? I was wondering if you have done any testing with the hole open and the hole closed?

I'm assuming you have cold air feed going from the lower front bumper to the inner wing?

[dynamix]

Cheers Houdini

Bro - not as much temporary but a 'i cant be arsed to make it look good by sourcing the proper subaru part number for the cover that fills the hole' type approach

Yes, logging of Charge Temperatures as well as Inlet Temps have shown a good reduction in temps.

I will dig out the pics, and data from this.

You will note one of the fog light blanks has been replaced with a wrx fog light surround - this feeds into 89 mm ID tubing into the inner arch.

Prior to the APS Cold Air Kit, this 89mm tubing was fed straight into the side of the standard airbox to remove the std hot air feed from above the radiator in the engine bay and the resonator box in the wing. This alone made a huge drop in charge temps.

Other measures have been done to reduce Charge Temps (i have a temp probe in the intercooler to throttle body pipe) as this is the thing that can kill engines very quickly. The higher the charge temp = the hotter the piston = the more chance of det = empty wallet. By concentrating early effort on lowering the charge temps it gives power for virtually free - making the car work like it does on cold fresh winter's mornings all year round

[dynamix]

Charge Temperatures:

cruise:

- std air box and snorkle = ambient +6
- std air box and cold air feed = ambient + 3
- std air box and cold air feed and throttle coolant re-route = ambient +2
- APS kit with cold air feed from bumper & throttle coolant reroute = ambient +0C

Using the IC waterspray lowers the cruise charge temp by around a further 2 degrees C and has a knock on effect on the rate of increase on wide open throttle runs. ie it slows it down.

Cold is good

The best value for money modification was removing or rather re-routing the thottle coolant feed. This dropped charge temps by a small amount but the biggest impact was on closed thottle, ie decelerating or standing at lights etc. With the coolant circulating the throttle body at circa 90C this heats the air waiting to go into the engine quite a lot ... and would rise to 60C in seconds.

With it removed it will stay at about ambient and rise by about .1 deg C every second ready for the next time that cold air is needed by the engine.

Cost of the mod =

[WR1 Bro]

Thanks for that. If charge temp is understandably so high on your agenda why have you not gone down the FMIC route? Are you of the opinion that the FMIC is too laggy?

[dynamix]

Curiosity and Cost mainly (cos I dont like spending money much).

I wanted to see what the std TMIC would handle - it still works great and still only get ambient + 20C even on very hard track sessions our at the end of the 2.5KM uphill flat out up Kesselchen at the Ring.

A lot of people go FMIC without having any facts to understand why they are doing it (or indeed if it has made it better) - i am a bit anal like that and want to know why I would be spending the money.

I probably will go down that route eventually with an APS kit as the quality of the IC makes a huge difference and with proper mapping, lag wouldnt be noticeable. Some of the ebay FMIC's are way worse than std at cooling and are laggy as hell.

[WR1 Bro]

Sorry if you have mentioned this, but where do you monitor your charge temp?

[dynamix]

I have an SPA Design guage in a pillar pod with the probe for this slipper under the hose between the TMIC and the throttle. The probe is 1 inch clear of any metal and sits in the air flow.

You can see the wire in this image:

[WR1 Bro]

I have an SPA Design guage in a pillar pod

Do you have any pictures of this?

The only charge temp monitor I've seen is a small digiat display in Marky Marks P1.

[dynamix]

here it is going over the forth road bridge. just pulled away from sitting in traffic jam for 1 mile. ambient temp was 23C.

[danr55]

one thing to bear in mind on the TM/FMIC debate is the Type 25 runs 420/440 ona top mount..