Top Mount Intercoolers V BHP - debate!
 

After some searching on here and discovering some old discussions, I was curious to what people are achieving on top mounts safely now technology and engineering has moved on?


I have personally run a tad over 400bhp on a TMIC on a 2.0 in the past, but have read people are claiming up to 460bhp, how safe can this be with heat soak?


I am interested in results for a built 2.5 which apparently running a little hotter than the 2.0, but I would run with an oil cooler anyway.


Thanks in advance.


Robert.

A lot of the heat soak debate depends on usage - if you're on track, then it's going to get hot. If you're going for the odd fast road blast, it's not going to get as hot.

General consensus from owners and tuners is that 400bhp is achievable with the right uprated turbo and injectors on a stock STI, although everyone's toy ends up being built differently :)

Interesting quote I've been given by a remapper when comparing TMIC to FMIC - again, based on uprated turbo, injectors etc. is "You are losing 20-30 bhp with the standard TMIC compared to a FMIC if you're looking to get over 400bhp"

physics havn't changed and intercooler tech hasnt moved on much.

Back to back test showed a gain of about 20bhp at 300bhp so 300 vs 320, but both ran safe, higher you go more improvement you'll see. as far as safe limit it really depends, pat backed mine off just over 400 as heat was becoming an issue. It varies from car to car.

Once you are far enough along to replace the stock turbo i'd sugest your at the level to change to a FMIC.

O and as far as FMIC causing noticeable lag, its a myth or a seriously crap setup.

Heat soak and under bonnet temperatures is the killer. Doesn't matter how good the TMIC is it lives in an oven.

Cheers all.


I've never had an engine fail on me, and I have pushed quite a few to the 400 marker before going FMIC. However having read that some coolers are now running safely over 400 I thought it was worth the debate. I recall John Felstead running over 400 on a fancy TMIC around 10 years ago and he was an active tracktime fan, surely something out there is more effective by now.


I'll be running a VF37 to begin with so the TMIC will be suffice for now, then looking to move onto something with a little more poke in the near future. However as the engine is out I was curious to whether its worth fitting a FMIC now whilst everything is easy to get too...

If your constantly on the move would say there good enough. Not as efficient as a FMIC but adequate. In a real world scenario stop start, traffic lights, traffic jams etc under bonnet temps rocket. If you monitor the temps they do rocket been there and done it.

If you get a proper fancy Gucci top mount, you can run upto 500, but better option is to just go fmic.
Agree with lag comment on a fmic, I don't think it's enough to even warrant it.
Even at 400hp I'd still want to run a fmic for efficiency and coolness. And you always make more up top end on a fmic.

you mean the £2000 one? :lol1:

and never run a front mount to see how many horses he's loosing.

a friend of mine was running a Hyperflow top mount and an SC46 on his 05 blobeye sti making mid 440hp. He installed a Perrin front mount, the car made a few more lb'sft torque but didn't actually make anymore bhp so it isn't always a given that you gain or lose by having or not having.
Trev

I think I have read about this on here, or something of a similar result.:thumb:


Well I didn't know that :freak3:.


I'm pretty sure I witnessed a car running a TMIC with a twin rad fan strapped to it some years ago, probably at TOTB or SSO.


Your probably right, just wanted to get peoples views.

:thumb: Think I have made my decision - I'll have a word with the builder :)

a CAIK does help a topmount in traffic as the spinning turbo pushes cooler air through the intercooler. Any cone in an enginebay even one with a feed up to it from the inner wing would draw engine temps in stop start traffic.
Just a point on the oil cooler Rob, you will find something like a 19 row mocal cooler will have a big impact on oil temps, this is good if doing a lot of track but just to consider your water stat, I have a 71deg and have an issue with low oil temps in normal driving so worth considering the standard thermostat.
Trev

John and his never gets warm super fandango top mount :lol1:



https://cimg7.ibsrv.net/gimg/www.sco...a00645fd39.png

Despite what bhp John may or may not be loosing, he would still show 99% of the people on this forum, a clean pair of heels on a track

there is also the flow rates to be considered between std TMIC and aftermarket FMIC's

i went from std hatch STi TMIC (the biggest std TMIC bar the s206 item) to an ETS 3.5" core FMIC.

peak was 1.4bar on TMIC, on FMIC we hit 1.7bar on same map before we reigned it all back in

There's one on every forum :Whatever_

^^ they look like the wheels and tyres I supplied John, ex WRC rubber too :D


Trev thanks for the advice on the cooler :)

There's is now you've joined the forum! :thumb:

Think you need to look into your childish statement. Then have a re think. Then come back and apologise :thumb:

I'd of done two laps by the time he'd cooled his top mount down with that leaf blower though Joe :lol1:


All joking aside, his driving skill was never in question. Most know he can move, but the thread was about differences in cooler types :thumb:

Trust me - it's humble and most sincere...

I cooked my engine, running 300 on a TMIC.
had a "play" with a Celica GT4 on a French motorway, queued for a toll booth, blasted away and the bottom end fell apart.

Now running 400/400+ on a forged 2.5 with FMIC.

At last somebody unfortunately with real world experience who isn't afraid to state what happens and why :thumb:

An anecdote matured in oak. ;)

Then what happened?

Bag Oil Dry I guess :idea:

Car was recovered to Calais, by the guy who fetched it off the motorway. It cost me around €700 in total, as Mrs Alcazar had decided we didn't need European breakdown cover. :Whatever_ The high cost was, in part, due to it being a Sunday.:(

I was actually booked on the ferry from Zeebrugge, but P&O changed it for me.

They towed me on board first, and off last.:(

The RAC breakdown cover took over and fetched it to near Ashford, then leant me a car to go home and it came home on a multi-drop three days later.

The late, great Harvey Smith then took the car and repaired it/rebuilt it as a "non-distressed repair". I fetched the car back the next May.

It now has a fully forged 2.5, 740cc injectors, HS TD05 20g turbo and FMIC, six speed box and uprated clutch kit.

Well if you're going to rebuild it, you may as well do it properly :)

Aye.

i just trurned it over to harve. He asked me what sort of power I'd like, and I said 400 or thereabouts. Numbers aren't really important with that sort of power/torque.
He just did what he needed to.

It sat in the corner of the specialist and was worked on on Friday afternoons when they hadn't any other work in.

TMIC. Anyone know at what speed and over what distance it has to be maintained for the temperatures to become dangerously high?

Not how it works.

The problems start with using the engine at higher poweres, then slowing/stopping, allowing heat soak. Whilst moving, the intercooler will continue to do just that. But stop, or slow for any length of time, underbonnet temperatures rise alarmingly. The intercooler gets VERY hot VERY quickly, and any air passing through it, until it again cools, is hot and not dense enough to contain enough oxygen. Detonation is the result.

Mine now has two temperature probes, one in the inlet AFTER the intercooler, one on the air filter. I can actaully SEE underbonnet temps rise when cruising, then slowing.

Harve had done a LOT of work on this problem. His work included looking at reverse scoops, or no scoop with an FMIC, (to which he concluded, don't do it for a road car), and the effects of various types of intercooler. His preferred one was the Hybrid GT, which he stocked.