Front or Top Mount

Tom's post about a new rad kicked off a train of thought about front mounts etc. - which may be completely wrong. I know its all been discussed to death elsewhere but I'm still not sure there is a clear winner either way.
It's all about the relative advantages and disadvantages of a front mount. Toms just fitting a more efficient rad which is probably (sorry if I'm wrong...) sitting behind a front mount that warms up the air before it gets to the water rad so most of the gain from the new rad will be lost. Put the FM back on top and the original rad will probably do the job. The R has a good scoop for the top mount so providing the car is moving it will be efficient.
A more efficient top mount seems a better and cheaper way to go for the sort of power levels I guess most of us are running.

Or is it all about appearances.

Its been said that the topmounts are only good for upto 1bar of boost because of the heat generated from the engine.
even when the car is rolling and you are getting good cold air flowing over the topmount, the heat of the engine still rises and makes the intake temps higher, thus causing the engine to suffer det.

Im no expert when it comes to tech talk, im a grease monkey lol
But i can see thats definatly whats going to happen! no matter how much air you get over the topmount or the size of the topmount.

I dont think the front mount being infront of the rad is going to be that much detremental? its having cold air forced through it, and dosnt get hot so the cold air will still be cold when it gets to the rad.

Yes, this is where it get to be a bit of guesswork for me too. With the airflow in through the bonnet scoop and down over the engine I would reckon that most of the engine heat is taken down and out the bottom - as long as the car is moving. When I stop after any journey the top mount always feels cold. (not very scientific) It warms up quite quickly when stationary but I can't see why I'd worry about that.
I agree that the cold air through the front mount is still cold but it's not as cold as it would be if the fm wasn't there.

People started swapping to front mounts because when you are in traffic they get hot very quickly and you can feel the car struggling setting off.If you are moving all the time then its not so much of an issue, but driving on British roads usually isn't like that.

From my research a general rule of thumb is top mount is fine to the around 1 bar mark possibly a touch more, and the top mount will make more power at lower boost than a front mount naturally. End of the day anything a bar and over you should be down to the tuners to check for det and excessive inlet charge temps etc.

Anything over that it's front mount time for sure

If I was to own another pulsar after my one it would be a simple standard spec, 1 bar boost - keep the top mount

Gone too far with my one to turn back now though lol

I have a ARC topmount and will always stick with this unless later i go down the route of bigger turbo i.e. gt2871 etc
My plan with my topmount as done by other owners is to try and put a shield under it to ty and keep away the heatsoak but still leaving enough gap for the air to sufficiently pass through it. Im also looking into other options...

The problem with putting a shield underneath is for it to be worthwhile its going to be thick enough to be too close to the i/c.Then the air won't pass through as well as if it was clear so creating another problem.
If I was to do it all again, I'd maybe use an ARC topmount and have water injection on it.You can try a waterspray onto the topmount i/c(I did) but it tends to find its way into the sparkplug holes.

skiddusmarkus wrote:The problem with putting a shield underneath is for it to be worthwhile its going to be thick enough to be too close to the i/c.Then the air won't pass through as well as if it was clear so creating another problem.
If I was to do it all again, I'd maybe use an ARC topmount and have water injection on it.You can try a waterspray onto the topmount i/c(I did) but it tends to find its way into the sparkplug holes.

Yeah its going to be a trial and error thing i reckon

I often pondered the option of a charge cooler, but got scared off cause I was unsure of the performance of one at high boost, and proper performance charge coolers are big bucks when you go back to placing it up against front mounts etc again.

has anyone actually ever bothered to check the charge temp's as the one bar thing stinks of tuner bullshit to me.

Dan the Gearboxman wrote:has anyone actually ever bothered to check the charge temp's as the one bar thing stinks of tuner bullshit to me.

Yes, I think this is what I was trying to get at. There is a lot of talk and guesswork but I've never seen any measurements.

Ive got a dual temp gauge kit to fit when i get time so i can measure charge temps before and after intercooler

I will be running 1.2bar on mine last of the big bhp mongs

Nice one, look forward to the results.
Then you have to put in the front mount for comparison.

I'm not going to put a fmic on sorry. Its staying standard besides the airfilter until I can get my hands on a standard airbox and then it will be completly standard under the bonet!

I'v got a standard airbox, would swap for some OE mats if you have some?

I'm just about to throw a fmic on mine. I'm runnin 1bar with the standard. What do you think the power gains are just bolting her up and taking her up the road?

Quicker spool time .... not sure in power increase tbh

I would imagine itul give it a few more brake. It did with an escort turbo I used to have. I'm hoping anyway as it is abit of a job to fit and moving stuff about. Will look good to.

Im not a great fan of the tmic look but is definatley alot better spool time .... obviously dependant on what fmic you have most seem to be the autobahn style .

Decent top mount spool quicker than all of the poor front mounts & most of the better ones too, have used arc & thermal shields on 2 pulsars & one at 1.3 bar & 370hp.
In Thailand due to very very hot climate quality front mounts are a must, in UK-Europe not such an issue ...
Top mount is very underestimated & the ARC or a recored top mount can keep temps very reasonable.
Would only go for decent front mount for big power & more serious track use cars, most road cars would be better performing on decent top mount & thermal shielding.

Top is definately the way to drive on twisty funny roads !!!!

i put a front mount on my R many years ago as wanted the peace of mind when i wound the boost up over 1 bar (standard internals - usual mods to support higher boost)

Over the years i thought lots about trying to fabricate - or at least design a much shorter pipe run to try and re-claim the faster spool or reduce the lag - however you look at it - that the TMIC provides.

Just wonder how restrcting it would be to have much tighter bends in the pipe work ?

i ran 1.2 bar on a top mount for about 5 years and used the car as a daily driver and no problem
would depend on the type of driving you do as for the heatsoak you get.since 1999 ive only got heatsoak from the top mount twice and both were from fast driving then coming to a traffic jam and sitting still or moving slowly for 10 mins or so
then when you look at the shit design and miles of pipework on a cheap front mount kit youd be better off keeping a topmount

Well I'm abit undesided now. The one I've got is a beast of a thing one that I had off bob with aluminium pipes does look like an autobahn one. I'm not bothered about abit of lag,nice 4 abit more bolt on power and I love the the mean look of the front mount.