Would like to hear from people who have done this. I'm well aware of the fact that any lag can be mapped out be a decent mapper but I would like to hear about how the car felt day to day, how was in gear response and driveability affected?

I've had it with the TMIC. It is just not up to the job IMO. After a sustained blast the other night in my Spec C I could feel the car noticeably backing off as the charge temps got higher and higher. Bugged the hell out of me.

Also, have people managed to successfully relocate the IC spray nozzles to the front of the car? Would hate the IC tank in the boot to go to waste!

 

When you convert to a FMIC the pipework that leads from the turbo outlet to the intake manifold is hugely increased.

It will take a longer time to pressurise this length of pipe before you see boost at the intake.

Please dont be under the impression that 'any lag can be mapped out by a decent mapper' because it simply can not. It can be played with until the best is achived but it will ALWAYS have far more lag than a TMIC. I am going back to a TMIC after a few years because I get so annoyed with the lag between changes. You do get used to it but its bugs the hell out of me!

 

The only thing I can suggest is find someone near you with a FMIC and try theirs to see if you can put up with it.

 

and you base that info on what exactly?

the lag you speak of is actualy an issue that the maf doesn't like the front mount (i assume due to flow rates) and can be sorted by doing away with the maf and using a map system instead.

the only other possible reason for there being lag on a front mount is the turbo isn't big enough to fill the front mount quick enough.

but the front mount istelf doesn't cause any lag so to speak of

 

Are you near me???

My JDM STI is basically the same, bar the Turbo bearing as standard.





The answer to all your questions are probably in here, and the pages either side.:

https://www.scoobynet.com/projects-4...se-2-a-15.html

 

I am well aware of those issues pal. I will go front mount and if I don;t like them simply change back and count it as a lesson learnt, it's the blast other night made it well apparent that cooling was the issue. I am considering a larger twin scroll to help things along and ceramic coating the exhaust system to improve gas speeds and hopefully reduce lag.

Would still like to hear if anyone has relocated their IC nozzle sprays to the front of the car.

 

Liam I wouldnt have thought it would have been difficult to extend the intercooler waterspray pipework to the front you could always use hoselok nozzles on a custom made bracket instead of the o/e nozzles have you thought about relocating the oil cooler or are you able to leave it in its origional position.

 

Tidgy - I have a MAP based system (Link) so dont have any issues with flow rate being a factor. Are you saying that the lag will not be increased (even if it is a small change) when changing to a FMIC?

Whats the length of pipework on a TMIC? ... 400mm taking in to acccount the Y-Piece and adding a bit.
Whats the length of pipework on a FMIC? ... 2000mm maybe more at a guess?

So estimating the pipe diameter at 80mm. Area = pi r sqaured, 4*4(changed to cm) * pi = 50.272 (round down to 50)

TMIC intercooler pipework volume is 50 * 40 = 90 cm cubed
FMIC intercooler pipework volume is 50 * 200 = 10000 cm cubed

Ok so the figuers are not exact but hopefully I am puttin my point across. When you change gear and the pressure is vented by the BOV then it will take more time for the system to fill again with pressurised air with the longer length of pipe work than it would with shorter pipework - I see it as law of physics more than anything.

..... or maybe I need a bigger turbo! hehe

 

Your 90 should be 900 but something you didn't mention.... The i/c cold pipe and the FMIC pipes in general are far bigger than the factory OE TMIC pipes. Plus, they tend to have more bends.... I also think your 2 metres is short. Factor in the contortions needed by most piping kits to avoid bits of chassis and the rad.....

J.

 

Hi Gus,

Yeah I was thinking along those lines with the IC spray. Not a huge effort involved really in order to extend the lines. The oil cooler could be relocated to one of the wheel arches.

Take a look to how this guy has done it. The pics are towards the botom of the page.

Type-RA.co.uk - Home of the Subaru Impreza WRX Type RA, Subaru Impreza WRX STi Type RA, Subaru Impreza Type RA V Limited :: View topic - MY06 STI Spec C Type RA

 

i converted from a larger tmic to an APS front mount and although i gain a little lag the extra power more than made up for it my water spray was lost tho, as it was not worth adding to the APS core

 

I originally considered that route and was going to fit a Hyperflow TMIC, but even then, it is still inside the engine bay.

Could I be seeing slightly larger inlet temps due to the fact that I still have the standard and restrictive OE exhaust system on? As such my turbo is obviously going to have to work little harder (and as such hotter) in order to send the exhaust gases.

 

not enough for it to be an issue, i say that after having a chat with one of the most highly respected mappers on here about the very subject.

 

i dont know how your sti intercooler works with the water spray but when my hyperflow tmic was on i used to go thru a tank full of water in about 150 miles !!

 

Liam,
I have seen those pics before seems a logical place to put it really.Have you been able to get a good price on the aps yet.

 

I'm sourcing it from the US adn so far it looks like I'll paying when converted roughly £750 for the IC and that includes delivery. Going for the same IC as in those pics.

 

Liam can you pm me some details.

 

Some of you will subscribe to Autospeed which covers a range of interesting technical features, often from an Australian perspective.
Here is what they had to say on the subject.

 

PM'd you mate.

Can anybody else out there who has gone from TMIC to FMIC please share their thoughts and experiences please?

 

I went from the slanty type found on the WRX's so will be a different IC that yours(which I would have thought was good enough) but when driving through the gears and especially when changing quick enough I haven't noticed any "lag" or less of a throttle response or even "it will ALWAYS have far more lag than a TMIC" as someone has said.

I would say it is very slightly noticable for me when sat in a high gear off boost/in vacuum and when I floor it but then that shouldn't matter because if it means so much to get the extra few tenths/car lengths then I would have just dropped a gear or two anyway.

Plus with the other mods I did to the car, the extra power would more than make up for it if it was extra laggy and less responsive in my case.

 

That must have been one sustained blast you did Liam
Never had any problems with my spec c when blatting around country lanes etc though the auto IC water spray button was permenantly on and it was amazing how quickly the water in the 12ltr tank went down (though it is normally cooler up here in the north )

Tony

 

Well according to my Defi's I saw nearly 110ºc in oil temp. Don't know how accurate they are but my senders are plugged into a sandwich plate between the block and filter.

I'm lucky enough to live close to where Top Gear and Evo do some of their testing along the Brecon Beacons so the roads are pretty quiet and you can have a very long, hard run. It wasn't my imagination, the car was definitely backing off and the IC tank sure went down a bit!

Going down the FMIC route was always something I said to myself I would never do but after the other night I've had to bite to the bullet and admit defeat. If I don't like the feel of the car afterwards then I can always change back and take it as a lesson learnt!

 

OMG, i cant beleive your thinking about a FMIC, or larger top mount, when you still have the O/E exhaust and cats on
surely you were joking when you posted that?
3" minimum & de cat, immeadiatly sir.that will reduce tempratures, + lag them, and your tubby.

 

i got a frount on my subaru p1 noyiced a wee bit of lag not much matbe a 200 300 rpm of a difference it is well worth it i think anyway

 

My Spec C is going in this week (hopefully) for the Perrin FMIC, will let you know how i get on

 

I don't want to fit a different exhaust yet mate. Have a Spec C Type RA which comes with a different STI backbox and I want to try and maintain a standard looking car. I am well aware that my inlet temps are higher because the turbo has to work harder due to the restrictive exhaust. If I do change I will only be going to a 2..5" system so that I can retain the standard b/b.

Thanks for the input though but I am really trying to find out from people how the car changed driveability wise from their perspective and whether they felt it changed for the better as I know some people have gone back to TMIC after going FMIC.

Please do.

 

Sorry, I'm confused, Increasing the charge area for a given turbo will not increase Lag? Who is this highly respected mapper?

 

Liam just noticed where your oil temp is plumbed in it will run hotter from that area mine is plumbed in abover no 1 cylinder it was plumbed in above number 3 but power station used that for plumbing in an extra oil feed to the hybrid twinscroll so they moved my sensor above no1 cylinder touchwood I have never yet had any problems with oil temps even after ragging it round Croft last summer in a heat wave but that was before I had the conversion done but was still running full 3" miltek and the standard vf36 and never found the power dropping off.

 

Its not going to look very std with a FMIC cut into the bumper !

I run my spec C at over 450bhp on the std TMIC with no power backing off after a hard run. In fact if anything as the exhaust gets fully hot it gets even faster !
I presume your car has been remapped to suit UK fuel ? If not then that would explain the power dropping off as the ignition timing retards itself.

There are more and more people removing their FMICs and going back to TMIC as they don't like the increased lag between gears.

Andy

 

I will going for an APS FMIC with a black core, which should give the car a very stealthy look. If you take a look at the link I posted further up the page you will pics of the IC fitted to a car and it is hardly noticeable once fitted.

My car was supplied by Litchfield so it has had a remap for UK fuel.