dominicm

These are a list of my Mod's on my STI RA MY95!!! Full GrpN catless exhaust, 550cc injectors, uprated fuel pump and reg, K&N air filter and the Link ECU package.

The car boosts to 21/22 psi and then settles back to about 18/17 psi, I'm getting nearly all the boost by 3000rpm so the car is super responsive with the RA gearbox!!!

I guess my next step is an uprated intercooler, my question is how will it improve my cars performance. I really can't see me safely running higher boost on the standard internals so is it worth spending over £600 on an intercooler

Cheers
Dom.

Pavlo

Yes.

Better intercooler means more same mass of air in engine at lower temps (and lower boost) which is safer and can create more power with suitable mapping.

Or you can run same boost and benefit from greater mass of air.

Standard angled topmount isn't great at all.

paul

dominicm

Cheers for the response Paul, I was thinking about the APS top mounted one for about £600, does anyone know how it performs?

Dom.

nom

I had the APS TMIC at one point - this was on a MY99, which I think has a significantly improved IC over the older cars in the first place? Anyway - yes, there were gains, but not particularly big ones. I think the actual 'cooling' effect was very similar to the standard MY99 IC, but offered significantly less resistance to airflow (less pressure drop) so the turbo (ickle TD04 at the time) seemed much 'happier' (technical stuff! ).
However... I switched to an APS FMIC (I like the APS tough fins) and the difference was very noticeable - a significant jump over the APS TMIC. This wasn't with the TD04 but an MD254 (which had also been run for some time on the TMIC).
IMHO, unless you have a good reason to stay with a TMIC (such as living in Switzerland ), skip it & go for a front mount.

CataIunya

How would mapping take advantage of the greater cool er air charge if no more boost was used....more advance ?

Delboy2

With better cooling the charge air density increases therefore the Air Fuel Ratio will increase thus leaning the fuel mixture. So the fuel map will need tweaking to account for this. When I changed from the standard slanty TMIC to a version 5/6 TMIC it was noticeable that AFR had leaned slightly on the Lambdalink when on WOT.

Cheers

[Edited by Delboy2 - 12/9/2003 2:52:14 PM]

Pavlo

MAF based cars shouldn't see a change in AFR. The mass of air is measured, and it's temp is not really subject to significant changes.

What can happen is you flow so much more air that the fuelling isn't able to keep up and you see an artificial leaning which wouldn't otherwise happen. Also, you may find yourself on a new leaner part of the same map, but this is unlikely with most subaru maps as they get very rich with increasing airflow.

Cars with MAP based ecus such as link, motec etc will require fuelling changes.

dominicm

I have a Link ECU so I don't use a MAF, so if I change to a FMIC I will cause my car to run lean beacause there would be more cooler air begin sucks in and therefore have to get Bob to do a remap to increase the fuelling and therefore increase the overall performance with out having to increase the boost level or Bob could even increase the boost slighly!!!

I guess the only decision is to go for an uprated TMIC or lash out on a FMIC which are a lot of money!!!

Dom.

hades

Personally - and I'm no great expert - I'd say an uprated TMIC is the right thing for (a) people who want to keep their TD04 or similarly small turbo, or (b) people who don't want to cut the bumper. For anyone after big power, with a bigger turbo, FMIC is the best way to go. IMHO, your turbo will be big enough to benefit from a FMIC.

There are two ways you'd benefit at the same boost level - one is stated above, from cooler air = increased charge density. The other - following up on nom's comment - you generally have a lower pressure drop across an uprated intercooler. Therefore, the turbo is likely to be running more efficiently, (which will mean cooler air anyway), creating less exhaust back pressure, so your volumetric efficieny will increase.

The other way of getting more power: I know of someone who fitted an uprated APS TMIC to a bugeye with the standard TD04, but then managed to get it custom mapped to run over 19psi held in the midrange. The I/C dropped about 2psi less than standard, so he was able to up the boost by nearly that much. He got 313bhp at PE, which is noticably higher than I've ever seen from anyone else with a TD04.

dominicm

I'm still not decided about which why to go, my car has a TD05 turbo and does run high boost without much drop already. As I said earlier I have well over 1 bar by 3000rpm so I don't have much lag!!

I do not want to cut up the bumper, lose lights or aircon so the only front mount will be the Pace, which hasn't had the best reviews on this BBS, to be honest all the uprated TMIC's haven't had the best reviews either!!

I just don't want to spend £1200 to have a slight increase in power and maybe an increase in turbo lag!!

Dom.