Carl Davey

iTrader: (3)

I feel a bit nervous starting a new thread in here while there are still some very high-profile big-build threads on the go but never the less i'm indulging myself in a bit of research so thought i'd post the results for all to see.

I'm sure it won't be new ground for many but i want to find out for myself what the effects are of various modifications aimed towards keeping Impreza Turbo air temps down. Do taller scoops, intercooler splitters and tilt kits actually work? Is it worth removing the water feeds and returns to the TB and IACV? How much warmer do inlet temps get with an 'open' K&N filter and how much cooler do they get with a shield fitted?

The list is endless! I already have my own beliefs as to which mods do and don't work but want to see (as close as possible) scientific proof. I also hope that later on if i chose to modify the car power-wise that these mods will provide a good grounding, something i was cynical of with my last project and paid the price for.

So how am i going to do this? All testing will be done on my standard MY98 STi RA and mods will be done in order of cost - cheapest first.



I plan to test each change individually, using a basic air charge temperature gauge to measure inlet temps over the course of a pre-determined route. This will involve taking the maximum readings at the following points after logging ambient temperature from a seperate thermometer:

Pre Ignition
Start-Up Cold Idle
10 Minute Warm Up
60mph Cruise
90mph Cruise
5-6 Minutes Hard Driving
5 Minute Warm Idle

I then plan to take series of readings from the engine bay using the infra-red thermometer i treated myself to a few months back. These will primarily be based on the air inlet tract but i'll be taking various other readings for reference - oil sump/filter for example. All this data will then be stuck in a spreadsheet to allow trends to be taken which will hopefully make for a good visual representation of the effects of different mods.

Carl Davey

iTrader: (3)

So i've spent the last couple of days laying the groundworks if you like. I've taken the opportunity to take the inlet manifold off and swap it for a freshly painted one while i fit the charge temp sensor, do the breather and parallel fuel mod as well as bin the carbon canister and re-route the necessary hoses. Some pics:

Scabby manifold.



Fresh manifold.



Thought i was going to get away without moving the alternator until i realised the wiring for the CTS etc was hiding beneath! On the bench.



Fookin' flakes of paint everywhere...



...so how'd you get rid of them?



Defi oil pressure sensor fitted while access is good.



New manifold part built up. Was going to wait for new TB/IACV gaskets but the ones off the original manifold looked fine. Manifold-head gaskets were definitely screwed though.



Think the original manifold didn't look too bad in the first pics? Rattling a screwdriver over it removed nearly all the paint.



So this morning i set about turning some off-cuts into plugs for the redundant breather ports. Also went and collected various gaskets, hose, p-clips and fittings.

Bungs fitted to inlet pipe.



Planning on routing the crank breather straight to atmosphere so binning the manifold NRV. Seemed an ideal place to mount the air temp sender.

Cut down NRV.



Some GF Nylon 66.



So theraputic...



Potted the sender in place with some superglue and it's mounted.



But it may need some Vigra to keep it's rigidity...



Have binned the OEM fuel pipes to do the parallel mod so routed the fuel tank vent direct to the chassis rail. Just rearranged the OEM pipes so no Stanley knife required.



I want to bin the purge valve now but not sure i can without upsetting the OEM ECU? Anyone know if it throws a fault code if you unplug it?

S.P.Developments

Looking forward to reading your findings,..

John

Fuzz

Should have called the thread "Cool Runnings"

No fault codes on mine when I did that.
This temp sender you potted into the GF/Nylon?
Is that how it comes in the group buy kit? (unpotted)

That non return valve is I assume the standard item from the back of the manifold?

Also looking forward to the results.

Andy

wadsy69

iTrader: (1)

It's strange seeing pics of an car you once owned! - but also really interesting too! Hope it all goes well Carl.

Martin

911

Another 'Carl' thread!
Excellent!

Martin: You just knew he couldn't keep his spanners off it....

Graham

edge

Great idea Carl!

Will be keeping a close watch on this thread, as I'm about to do some of these modifications myself.

BTW, any news on your other projects?

Paulo

andy97

iTrader: (1)

Carl will you be measuring the inlet manifold casting temperature, before fitting spacers and after fitting spacer?

Seen as you sell them it would be a good selling point to show, hopefully a significant temp drop with your spacers fitted


Andy

Carl Davey

iTrader: (3)

Andy yes, standard NRV cut down.



I got the Nomad kit a while back and the sender came in a nasty plastic 1/8 NPT > push fit elbow. i.e. the elbow had been modified to accept the sender before the kit was sent out. You can just see the remains of it in the pic below.



Andy97, i plan to measure a couple of points down the centre of the manifold and also the start and end of each runner. I have already gathered one set of results from the engine bay after i recce'd the route for gathering the charge temps. Casting temps just above the injector on each runner varied by up to 54 degrees. I do plan to test the insulating spacers but not for a while yet as they are an expensive mod compared to others i want to test.

Carl Davey

iTrader: (3)

Binned the purge valve on Andys word this morning and threw the manifold back on the car.



Breather routing.



Found a nice 'spare' M8 tapped hole in the gearbox so used it to hold a couple of P-clips to stop the hoses going wandering. Trimming the hoses once i'd cable tied them together cost me the tip of my right index finger! Clumsy bugger.



Billet rails i had made.



One-off distribution block too as i want to keep the OEM regulator for the time being. With hindsight i'd just use T-pieces next time but i got obsessed with using shallow Y-junctions to aid flow. Looks nice and will work but is a PITA to mount anywhere in a standard engine bay.



Couple more fuel hoses to run tomorrow before leak testing the rails.



Can anyone tell me if i pull off the cam sensor wiring and turn the car over on the starter will it make oil/fuel pressure but not start? Off to do a search...

Fuzz

Cam sensor is a sync sensor so ECU will not know which stroke it's on and so wont fire.
Fuel pressure will be made by switching IGN on
Oil pressure will be made once cranked.
Andy

vulnax999

iTrader: (7)

Carl

Just pull off the crank sensor under the alternator, won't start and will make oil pressure on turn over - the way the oil change procedure does to protect "dry" bearings after a change!
Fuel pump will pressurise the fuel system on IGN key position.

Fuzz

One question though,
Is it going to be just toy or a track weapon...

It's just that if it spits out the breathers a lot when on track (which it probably will do if you have a standard sump and high grip levels) you might just cause an arseident.

Andy

Carl Davey

iTrader: (3)

Concern i had was full fuel pressure wouldn't be made as IIRC the pump only goes live for a few secs on ignition? Cam sensor seemed easier to reach - have half an index finger now.

Really want to turn the engine over with the plugs out as there was a minor coolant spill over #3 while the manifold was off... Luckily it wasn't on the inlet stroke and the strongest soaker upper came to the rescue but i want to be sure. Kitchen roll that was already in the port soon saturated.

Arseident lol. It's just a toy for now Andy but i'm going to keep my eye out for a decent catch can anyway. I'll be keeping a close eye on the breathers too as i'm still very protective of my garage floor and driveway. How being a home-owner changes you! Didn't seem to matter as much when it was Dads.

drb5

iTrader: (4)

Coolant spillage won't matter Carl, as it'll be burnt off almost instantly.

Looks mint though....just a shame you put such a lovely manifold in that engine bay! Looks a tad out of place.

I have a Helix can if you want it?

Daniel-S

Will be very interested in the results of this

Fuzz

I'd be careful of saying that Dave, if the cylinder is flooded, it will hydraulic long before it has had time to burn off.

Andy

drb5

iTrader: (4)

From what Carl said, i took it as only a little amount. Obviously if it's flooded then yer a bit different.

Carl Davey

iTrader: (3)

Yeah, i heard (from a not very reliable source) a while back that it only takes a teaspoon of water to kill an engine? I doubt that's true but better safe than sorry. I do plan to tidy up the rest of the bay a bit at a time but want to see how my paint work on the manifold stands up to the jet wash first.

Fuel system given the mouth-vacuum test (anybody else watching American Chopper last night ) and passed so leak tested at 2 barg, 3 barg, 5 barg and then 6 barg. Only minor leak was from the blow-gun i'd bodged onto the fuel supply pipe and even that ceased at 4.5 barg.

Wiring all run out for the Defi senders and ACT gauge. PITA trying to get the intercooler back on with the strut brace in the way, ended up removing the brace in the end. Something to be said for UK's...

All ready to be cranked in the morning - with Dad standing by! Just leaves the plugs to be put back in (now gapped to 0.8mm), air-box/MAF, get the gauges installed and then get on with it!

Fuzz

why 0.8

Normally 0.7


However many CC's your combustion chamber is, equals the amount of fluid needed to hydraulic the thing.

maybe 4 teaspoons


Andy

Welloilbeefhooked

iTrader: (3)

Is it me Carl, or are there no spacers under the new manifold?

Welloilbeefhooked

iTrader: (3)

Also, have you thought about a cycle water bottle as a cheap catch can. The oil dripping on the drive is a pain!

I was thinking about how the flow of air from the turbo enters the engine. Am I right in thinking that the smoother the path, the less work the turbo has to do to achive the same power, and that the boosted air would be cooler?

The areas I am thinking about are these:

TB
Alloys IC Intakes
Manifold the head matching

Fuzz

both sides of the turbo have an effect.
Inlet tract to the compressor housing as well as pipework through intercooler, throttle body, inlet manifold and head.

Notice all the little things like you describe above, I actually did.
Nice bell mouth under a free flowing K+N, smooth bends to compressor. smooth bends into intercooler, removing screw threads on the throttle plate and knife edging it, buffing the inside of the inlet manifold to a smooth a finish as possible, then matching inlet manifold to the head.
Making the hot gas come out smoothly has just the same effect.


Andy

Carl Davey

iTrader: (3)

Knew i gapped the ones in my last car to 0.7mm but couldn't remember the 'standard' gap (SNet down). Figured there was no danger of the spark being blown out under standard boost pressure so aimed high for a stronger spark.

Plan to test the spacers later Wayne.

Scoobyslammed

Looking good... interesting thread mate...

tfl55

If you bin the carbon canister, do you have to re-route the pipes left from where you disconected the 2 hoses from the canister????

Terry

p1prodrive

iTrader: (3)

i too would like to know this !

Fuzz

with the offending metal pipework removed from under the manifold. the vent pipe from the fuel tank was just pointed down into the chassis via a suitable hole.

The other hose that goes back to inlet pipe was junked also as I was making a different inlet pipe.
If you keep the standard inlet pipe you'd need to cover the hole with say a wrap or two of insulation tape.

Andy

tfl55

Thanks Andy,

Any Phots????? I know you have a lot to do, but if you get time Gracias.

Terry

p1mark

Like the mounting of the temp sender Carl . gonna have to copy it im afraid. Mines in the TB hose so wont be picking up heat in the charge from the inlet manifold - This is a far more accurate position so see what the engine is actually getting.