WRX 2008 STI top mount fitment?

[cynner]

Does anyone know if the STI tmic can be fitted to the Liberty GT?

Apparently it is better than the Process West... see here: http://forums.nasioc.com/forums/showthr ... ?t=2348764

I was thinking of fitting the Process West TMIC, but the STI one would be cheaper. Just not sure about fitment...

Kim

[alexeiwoody]

Hi Kim,

Getting the sti to fit will be difficult as it has different mounting points, and turbo side inlet. So it will cost you a few $$ to get that setup well. Still potentially a cheaper option than the $990 for PW (which comes as full bolt on solution).

In re: to the nasioc thread, pay attention to Clark Turner's posts. He is arguably one of the best tuners in the world. Tunes just about everything from daily drivers to serious STI/gtr35 skyline racecars.

IMO they didn't test the PW properly - it comes with a hood shroud, which makes ALL the difference. Their tests results also make no sense. A smaller intercooler, will be outperformed by a larger one in at least one area, somehow their stock one works wonders all over the scale You'll see a bunch of educated people drawing the same conclusion by page 3 iirc.

Pw is great but maybe not needed depending on your needs and boost?

[cynner]

Cool thanks for the info!

Current mods are PW cold air intake/pod, 3" tbe, kobe silicon inlet/short fat bit, 3-port boost solenoid, 15.5 psi. Estimated 190-200kw atw (will be dyno'd in a week).

For now i'll keep the stock turbo (maybe upgrade in the distant future). Was told bigger top mount would increase flow to turbo and allow it to spool quicker...?

[Manaz]

That thread is interesting.

Certainly, the PW is much bigger. All other things being equal, it will absolutely require longer to cool down, as it can absorb more heat.

With appropriate airflow though, I would expect it would also take longer to warm up than the STI (or any smaller TMIC).

Dyno testing doesn't really replicate real-world conditions. Unless you're on a racetrack (and that's a perfectly good use case on its own), it's rare that you spend a lot of time on boost. When off boost, air temps aren't as big an issue - and if the car is moving, it's cooling the core down again.

Speaking of the car moving (or rather not) - on public roads, particularly in stop-start traffic, you also spend a lot of time with no airflow. What happens at this point, particularly with a TMIC, is that heat rises off the engine and passes through the TMIC. Again, all things being equal, a larger TMIC will be impacted less by this (but admittedly will take longer to cool down again once air starts flowing again).

I'm rather surprised by some of the results in the first post in that thread, I'm very surprised that the air temps after the PW intercooler were warmer than stock, particularly after a pull, when I'd expect the larger size of the PW TMIC to benefit the most.

I am actually seriously considering the PW TMIC, and using a water spray system (there are a few "intelligent" designs floating around) to control the heat of the TMIC itself (and thus minimise the issue of heatsoak and slow heat release).

[alexeiwoody]

Kim - I don't think a bigger top mount affects spool, although it will help power somewhat. As it's placed after the turbo, it can't very well add more air to it, only to aid efficiency by being free flowing (ie don't buy cheap imitations).

Rob - that's also what I thought, their tests seem skewed, although they tested on the road and the dyno supposedly. They didn't even bother testing the AVO, because they simply didn't like the look of the design? Anyway - If Clark Turner says PW is better and makes 10whp more, it's better and makes 10whp more.

To answer the original question, the STI topmount is crimped and won't hold boost as well. It's also a different shape to your stock one and simply installing the STI without a new shroud to optimise the airflow through it - you'll probably be worse off.

On the other hand the PW allows you more boost, comes with a purpose specific hood shroud and I can tell you it works. Take it for a few 3rd gear pulls upto 170km/hr, pop the hood. The cold side is actually cold! It's absolutely fantastic

[peadya100]

Cool thanks for the info!

Current mods are PW cold air intake/pod, 3" tbe, kobe silicon inlet/short fat bit, 3-port boost solenoid, 15.5 psi. Estimated 190-200kw atw (will be dyno'd in a week).

For now i'll keep the stock turbo (maybe upgrade in the distant future). Was told bigger top mount would increase flow to turbo and allow it to spool quicker...?

My tuner is adamant that the stock TMIC is better than the after market top mounts... His main reason is the extra weight of the after market top mounts makes them take longer to cool down and are therefore no good in city conditions. His recommendation is the stock cooler with a water spray kit. Thats gone into the too hard basket for me though

P.S. thats an impressive power figure for those mods and boost pressure!!

[bigBADbenny]

Some observations...

All the sti version tmics are substantially different designs to LGT tmics.
They use a straight turbo outlet to Y pipe to a north-south cooler core to central inlet.
You'd only bother if upgrading(?) to an alloy inlet mani.
LGT tmics are west-east airflow.
Meaning the LGT PW tmic needs a lot of piping on the turbo outlet end plus a full 360 degrees of bends.
Not that that's the end of the world, but less can be moar.....

But any tmic will shine with a properly set up waterspray....

[cynner]

Hm interesting. Every time I make up my mind and decide to go ahead with a top mount, I read something else and change my mind again...

[Manaz]

My tuner is adamant that the stock TMIC is better than the after market top mounts... His main reason is the extra weight of the after market top mounts makes them take longer to cool down and are therefore no good in city conditions. His recommendation is the stock cooler with a water spray kit. Thats gone into the too hard basket for me though

Yep, I know who gave that opinion, and he's right in that it will take more time to shed heat than a smaller core - but it also takes longer to warm up (as it has a higher thermal mass - ie it can absorb more heat energy for every 1ºC that the core temperature rises).

That's why I want to combine a water spray with mine - to keep it cooler to start with, and to accelerate the cooling process when possible.

[bigBADbenny]

The stock tmics are not long term reliable over 18psi unless reinforced.
Thus the popularity of upgrade welded tmics

[peadya100]

Can someone please tell me once and for all whether or not there is a performance gain with after market top mounts?

I understand that they may keep the air cooler for longer and cool air is denser... and ive now learnt from BBB that theyre a longevity thing at high psi... I know theres not much (if any) gain in peak power with them, but is there a performance gain in the mid range at least?

[cynner]

I've been trying to find out much the same. I spoke to Kev at Process West, he estimated around 10kw improvement.

I'd kind of like to know if someone has had a tuned car (maybe exhaust, etc) then fitted a top mount and had a re-tune... is there a noticeable "bang for your buck" improvement? I've found lots of people who have said it made a huge difference - but they all did other mods at the same time (eg: going from a stock car to a car with exhaust, top mount, air intake and re-tune... so many variables there, it's hard to say if the top mount played any part in the gains at all)...

[peadya100]

I've been trying to find out much the same. I spoke to Kev at Process West, he estimated around 10kw improvement.

I'd kind of like to know if someone has had a tuned car (maybe exhaust, etc) then fitted a top mount and had a re-tune... is there a noticeable "bang for your buck" improvement? I've found lots of people who have said it made a huge difference - but they all did other mods at the same time (eg: going from a stock car to a car with exhaust, top mount, air intake and re-tune... so many variables there, it's hard to say if the top mount played any part in the gains at all)...

Im glad im not the only one having this issue.

Id love to trust Kev at process west on his power estimates, but you can never trust the manufacturers. If that was the case my K&N panel filter will gain me 10kw hahahaha

If it really did give a 10kW gain id buy one right now!

[cynner]

Further interesting reading here: http://rusubaru.com/intercooler-efficiency/ (more FMIC vs TMIC - but they seem to suggest an aftermarket TMIC is good)

[peadya100]

I think there is no question that it would be an improvement in cooling... which in turn is going to keep your car running at its best for longer.. but ive never over heated my stock top mount, so if thats the only improvement i couldnt justify the $1,000+ to upgrade to a PW. That would be more beneficial for track work or long spirited drives i would imagine.