butler

Hi guys was looking for advice on upgrading my top mount on my sti v3. Was looking at the autobahn top mounts on flat4 online website, Does any one have one or experienced won? Cheers lee

silent running

Think the consensus is that aftermarket top mounts are a waste of time unless they're the big name expensive ones e.g. APS, Hyperflow etc. Or an STi8.

Arch

iTrader: (59)

You can fit a new age WRX top mount to a classic with a few minor mods.
Would be pretty cheap as well. You can pick the WRX ones up pretty cheap as most newage WRX owners upgrade to the STI top mount so plenty around. Depends on budget really.

butler

Might just be better to stick with my oe top mount?

James Neill

iTrader: (1)

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silent running

To put it in very simple terms IMHO on a classic, if you want value for money and performance, fit a cheap FMIC. STi8 TMICs (it would be pointless to fit any lesser top mount) can be fitted to classics, but when you tot up the fact that they're often the same price as a whole FMIC kit even though second hand, you still have to start cutting stuff and repositioning things, you need to fit a properly sized STi8 scoop and undertray etc etc...it looks to me that you'd be spending at least twice as much money if not more on a top mount conversion.

Mr Footlong

iTrader: (7)

I run a Hyperflow TMIC on my 99 classic and it was pretty pricey (£550). It isn't simply a drop on job either. It is a very deep intecooler compared with the standard classic ones. I had to dremel a fair amount off the undertray as the hyperflow was so tall. I also had to cut out the 2 sides and the front of the undertray a bit to give a perfect fit.

Although you introduce the LAG question when you go front mount, I have to agree and say that you need to consider it as an alternative to your plans.

A pic showing the depth of the Hyperflow:



More pics here is you feel the need:

Index of /clanftp/nick/scoobs/fluffy/tmic

Cheers,

Nick .

harvey

iTrader: (48)

Very interesting.

I think a lot of crap has been talked by so called experts as to the merits of TMICs over FMICs. Without measuring and logging ambient temperature and air charge temperature I don't see how you can form a valid opinion.
For some time I have been measuring ambient and ACT temperatures on an APS front mount intercooler equipped STi 6 Wagon somewhere about 600 bhp, a 95 WRX Wagon 422 bhp with Hybrid Front Mount Intercooler and STi 3 Wagon with OE TMIC and around 335 bhp.
On the OE intercooler the STi 3 was reaching charge temperatures of around 60 deg. C in the sprint to 100 mph and off the clock at 70 deg.C by 120 mph.
The performance of both the FMICs referred to above were very similar, running around ambient or 2 degrees over ambient in normal road use, rarely reaching 6 deg. over ambient when worked hard on the road and typically 12 degrees over ambient on track.
All these figures relate to the car while moving.

On the STi 3 Wagon I experimented with an STi 7 scoop which made little difference and certainly not enough to warrant the expense.
I then tried an STi 8 scoop and it was obvious it was working at a lower speed, say 45 mph, whereas the STi 3 scoop probably didn't work until 55 or 60 mph. The improvement from the STi 8 scoop was noticable but it did not stop ACT of 60-70 degrees and then off the clock and what was very worrying was how easily these temperatures were achieved.

I then obtained a New Age STi TMIC. Originally I envisaged this would take a day to fit but it extended into three days work. During this time I could easily have fitted 3 FMICs and had a day left over.
I was going to relocate the clutch reservoir but ended up leaving it in place because there was no where to put it. Filling the clutch reservoir now involves removing the TMIC. The ICVS was relocated to the passenger side of the new TMIC. I had intended to use the STi 8 BOV but that was too tall for the bonnet and the STi 3 BOV was reused, located under the new TMIC.

The results were very disappointing without the under bonnet tray from the STi 8. I have since made my own under bonnet tray as the STi 8 tray was on loan.
Similarly, the results with the OE STi 3 or STi 7 scoop left a lot to be desired.

With the STi 8 scoop and under bonnet tray the results were better than expected but not as good as those achieved from an FMIC especially taking into account that both FMIC equipped cars are operating at 100-200 plus bhp above the STi 3 output.

The cost of this experiment has been far in excess of the cost of a good FMIC kit and that excludes the time element which for the TMIC was considerable. I may well fit an FMIC at a later stage or before next Summer.

Currently I have to resolve a couple of issues with the TMIC, particularly the banging of the alloy feed pipes and end tank which is particularly irksome and finding a solution is hampered by lack of space and general headroom to the bonnet.

I also copied the following from an Autospeed article and I believe that if an FMIC installation adds significantly to the lag, the FMIC kit is of poor design or the car has not been properly remapped for the FMIC.

typeRv4

https://www.scoobynet.com/general-te...ic-review.html

Aztec Performance Ltd

iTrader: (234)

good read: https://www.scoobynet.com/general-te...ml#post7058266

Mr Footlong

iTrader: (7)

Did you find like me that it doesn't sit flush where it mates to the Inlet manifold. The mouth of the TMIC sits slightly higher than the inlet mouth.

You were lucky that you had to do so little to maintain a good seal and also keep the undertray. The guys that fitted mine had no choice to remove it and to my concern also mapped her without any sort of undertray in place!

I was really fussy about making sure that 100% of the surface area so enlarged the duct as well as cut away the parts that bent downwards.

silent running

Damn! Seeing that picture of that TMIC it's more like trying to fit a microwave oven in than a top mount!

To back up what Harvey's saying, not that he needs any backup from me, I had a v4 STi TMIC on my classic wagon and it could not control charge temps beyond just normal driving. With long runs through the gears it would be hitting 50-75 degrees and beyond, well past the point at which most experts would want to keep charge temps and into the zone where you're going to be getting serious det problems if you don't back off the timing severely. The top mount might be good enough for a quick headline power pull on a rolling road, but in hard use it was ****. Even in everyday use as soon as you slowed down it started soaking up heat like a sponge.

Changed to a FMIC and it's a totally different story. In normal driving I find it running at 5-8 degrees above ambient and best of all, short blasts do absolutely nothing to the charge temp - nothing. I just did a trackday last week and I was seeing around consistently around 15 degrees above ambient; this was using 1.45 bar of boost. The highest it hit all day was 36 degrees IIRC.

johnnyroper

agreed when i was looking for sti8 top mount they were ranging between £200-£250 second hand,in the end i got an autobahn88 fmic off ebay for £170 all in.
have a look in the group buy section i think kips was running a group buy on autobahnn88 fmic's for about £190 delivered

typeRv4

Seems to fit ok on mine.

butler

Thanks for the info guys, a lot of points to take in. Sounds like i'm better going for a front mount after all. Going to get the autobahn fmic. Are fmic hard to fit? And how much cutting and repositioning things are required?

johnnyroper

i did not have much trouble fitting it,but the bumper cutting was time consuming i did a bit at a time to avoid hacking off loads and it looking a mess.
i did not need to reposition anything on my car but not sure about classic.

have a look in the projects section kips has done a good write up and put some decent pictures on there about fitting a front mount.

Andy.F

Don't forget the pressure drop across the pipework and cooler on a FMIC install. The extra volume can also introduce surge and part throttle response issues that just don't exist on a TMIC.

The Type 25 Impreza runs a TMIC at over 400bhp and is designed for track use.

For the quickest throttle response and quick boost recovery after a gearshift a TMIC is the answer, I have retained a TMIC on my spec C with 450+bhp and 500+lbft of torque yet I have a few FMIC's sitting redundant on the shelf !
Its perfect for road use. For track use at over 450bhp I would consider A fmic

Here is what someone had to say recently about his move to a FMIC

More interesting reading here - https://www.scoobynet.com/scoobynet-...es-please.html

borat52

Its a case of tools for the job and not bodging it up with frustration half way through. If you have a pre facelift(<1996?) then you will need to cut a small hole in the inner wing, this is not a tough job with the right tools but pays to take your time and make it neat and as small as possible. The real bitch is the front bumper as its a case of cut a bit, see if its enough, cut a bit more ect. Once again, cutting just enough will make the end job look way more professional than if you go overboard and leave big gaps. Another stumbling point can be the pipe that goes between the cam cover and the radiator as the rad fan makes this a v.tight fit, the best solution I have seen is one of harvey's where he mounted a single fan in the centre of the rad, very neat indeed.

One thing to remember is to ensure all of the joints are sealed properly, a top tip that APi posted on here was to ensure all joints are clean and free from oil and dirt and then spray hairspray onto them immediately prior to fitting the silicon hose joiners. Tighten the jubilee's with a screwdriver (preferably with a socket end) and leave to dry for several hours, or even better days. Do not overtighten as they can bend the pipes making a seal very hard to achieve.

If you dont get a good seal the car will drive like a total dog.

Took me 3 days in winter to do mine the first time around, easy once you have been through it before though.

borat52

Andy,
From my experience an 'elastic' throttle response is symptomatic of a leak in the system, a well fitted FMIC in my opinion should not cause an elastic sensation on the throttle. I have had a poorly sealed FMIC and have these symptoms exactly, been in another car with a properly sealed FMIC and was not able to notice any difference in throttle response over a top mount.

I do bow to your superior knowledge of impreza's and also my lowly level of driving possibly leaving me unable to pick up on the difference though

typeRv4

FWIW - my reasoning in going with a TMIC were this.

Car v4 type R.

This car is a road car 99.99% of the year. So drivability is what i want. Im looking for 350-400hp which i believe is quite adequate / enjoyable for a public road.

From my research here and elsewhere that a larger than my stock TMIC (v4 sti that is) would do the job powerwise. To me getting a fmic would be like getting too big a turbo. Sure u get the power but at what cost ? To me you have to get the right size both turbo + IC for the application.

Too many people try and wring the last kw out of a too small turbo way out of its efficiency range and then blame the intercooler - lol

So it seems a no brainer to get a interccoler that would do the job with the shortest possible piping.

Its just horses for courses.

harvey

iTrader: (48)

Several points.

If you have a Classic with O/E TMIC and it is tuned to a medium level, you already have relatively high charge temperatures. The Subaru TMIC has evolved, model on model, all the way through to the M/Y 2007. The New Age FMIC installations are far more capable than the Classic and from STi 8 onwards there is a noticable improvement but this has to incorporate a much more prominent scoop and the O/E underplate to achieve the benefits which still lag a bit behind a competant FMIC.

Fitting these satisfactorily to a Classics is a PITA and likely to cost as much or more than a competant FMIC installation. Certainly, the time element was far greater for me.

Some of the cheap FMIC cores are bar and plate and by virtue of their design they will have a greater pressure drop across the core than a slightly more expensive tube and fin which is also lighter.

steve ball

With all the discussions concerning the top mounts/ stroke front mounts, could i throw this question in? When i was modding my my 00 uk classic from a full de-cat and ekutek map to a vf 35, warlbro 255 and a fuel reg. I opted for an autobahn top mount from flat4online because they are rated upto 350 bhp???. I could see the boys at scoobyclinic didn't look overly convinced with it but they fitted it anyway and gave me my oem topmount back in my boot....... The boys seemed happy with my power output of 303/280 and i have had no problems since the work done, car goes well.

Anyway my question after reading some of the threads, should i bolt back my standard top mount if they are good for 300-330 bhp? (i didn't know this when i bought the autobahn) Would i gain any benefits or would it upsette the map and running of my car?? Or would you suggest to stick with the current top mount and not worry that i could of squeezed a few more bhp with the my 00 uk classic topmount??

cheers steve

johnnyroper

if you are happy with the car the way it is i would just leave it.

in my opinion i cannot see there would be much to gain from putting the original back on,but i do stand to be corrected if i am wrong

WREXY

Do you have the "elastic band" throttle response?

typeRv4

Its hard to say without testing - The Autobahn one is probably superior to the subaru one which is pretty small on a classic.

The map should cope with you swapping tho.

steve ball

wouldn't say so, i suppose the turbo spools slightly later than the tdo4 but i mean slightly! But its worth it ith that extra punch of boost