I've installed some K type thermocouples before and after the i/c and I've recorded a few readings.

Post i/c max temp on the move = 42 deg
Post i/c max temp cruise = 22 deg (warm day) 18 deg (damp/cold day)
Post i/c max temp after fast run and into traffic (near stationary) = 66 deg

Max drop from pre to post i/c = 76 deg

I will do some more logging soon when I work out a repeatable method!

What should I be seeing and what is bad for certain conditions?
F
PS message for John Banks - I saw your plots at PE yesterday, where's the story then?

 

Over 45 degrees and you end up retarding timing if you are running on the knock limit already. I am aiming to keep below 50 peak on the road so it stays below 60 on the track. You can go higher, but I wouldn't like to. The heatsoak always means you go higher after a blast then stopping - makes you think twice about piling away from lights on a hot day after you have stopped for a few minutes after a thrash!

What boost are you running?

With the hybrid and Tek 3 I was running the same power and torque peak but fatter curves using 1.5-2 PSI less boost across the range compared with the Dawes. It is a very conservative map indeed - there is more to come - gradually, with lots of monitoring and we'll see how we go.

 

I wouldn't want to go above 50 on the track but that is based on guesswork and not on solid fact.

Anyone know (technically) what is and is not a "safe" figure for road and track ('cos I'm presuming that these two are different?)

At Bedford I didn't see more than 45degC but that's on a UK running 1.0bar boost using the Dawes. It also didn't make any difference how long I stayed out but I was changing up by 6500....

Matt

 

John

The boost is about 15psi held in the warm weather.

42deg max was going "very fast" and I'd like to see if it rises above a certain speed threshold, which may indicate the aerodynamic innefficiency theory.

The idea behind the measuring was to see the effectiveness of the splitter and possibly the best position/height etc. I shall cruise at 60 mph and see what temps are with and without (back to back), unless anyone else has a better idea?

I'll then move onto water spray testing. It would be nice to see the max temps drop a good few degrees with this.

I have fitted the thermocouple between the hoses and it's clamped with the jubilee clips. Will there be any problems or leaks to worry about like this?

F

 

R19KET reported that he had a MRT uprated TMIC which gave an improvement of 20degs!!!

How much better can a FMIC get???

Is a FMIC worth the downside of long pipe runs for the extra gain in lower temps?

Are the MRT items the same design (bar/plate etc)???

I was hoping to see 5+ degs improvement with tweeks to the std TMIC, has anyone else seen this gain?

F

 

Ooohhh eeerrr!

Ambient 20 degs, coming home tonight I saw some alarming temps:

Stuck in traffic the inlet temps (post i/c) rose to 56 degs, then on the move slowly, it dropped to 30ish. Went for an overtake from 30 MPH and took a couple of cars and temps shot up to 45 before cooling to low 20's at 45 MPH.

I then came off a roundabout, after sitting for a while to get on it and booted it on a dual carridgway section. The temp rose to 49 degs rather rapidly at WOT before the i/c started to do its stuff and reduce it to low 30's.

The conclusion is whilst on track you may get a consistant air flow and temps will oscillate around 38-45 say, but on the road an in traffic you can get spikes of high temps very very quickly before the TMIC gets going (sort of like a cooling lag effect).

This could mean on a very hot day your temps could be 60+ in traffic and you could blast away onto a dual carridgeway at WOT and your temps could go silly high.

I've not tried sustained high speed so I can't comment there. It looks like a diy spray kit with thermostat/pressure swith may be a good idea.

F

 

Your temperatures do not surprise me or alarm me. Just have to be cautious after sitting for a long time - same on the first lap out - temps can be easily 70 degrees after sitting in the pit lane.

 

What are you using to log temperatures? Shame my data aquisition system is mains only...

I've seen some cheap serial based loggers though good for 10hz or so.

Paul

 

RS51 from www.rswww.com - can store peak and also hold values, but obviously it is not logging.

 

John,

'Over 45 degrees and you end up retarding timing if you are running on the knock limit already'

could you tell me if the above a is pre or post cooler temp?

im guessing post? its just im going to install a charge temp sensor between the cooler and the manifold, and just want some idea of what temps i should aim to stay below.

thanks, ian

 

I say that based on what some GEMS mappers had found - they can map for these things It was an actual intake temperature which was discussed - ie post cooler of whatever description.

I have noticed whilst leaning mine out from 920 to 890 mV (stinky rich to 9% CO) across the range that it can induce (small amounts - just a few degrees) knock retard even though the mixture is still very rich. If super rich it does still seem to favourably move the knock threshold.

This is why I also said if the ignition was already on the edge - when you first change a Subaru map from boggo standard nothing seems to make it retard (I could add 8 degrees in a lot of areas of the map compared to the AE801 MY99 ECU, although my airflow was well outside the zones that the maps were properly setup for), go a bit further and the suspect zones in the mapping poke their head out, continue a bit more and you get a few more. I have filled those in and am now stopping until I get it on the track and see how it behaves.

 

John

I agree, you should be cautious on the first lap after a hot pit lane queue senario, but then the first lap should be cautious anyway, right?

The warning here is that things can get very hot, very quickly in the summer, especially in clogged traffic. Go for the overtake after sitting at 30mph and pray that your chosen ECU can do it's protection thing because it's goiong to need to!

I'd like a waterspray system with a thermostat to arm it and pressure switch to activate. I bet you could come up with a system couldn't you John????

F

 

My first plan is some jets installed on the designated areas connected to the headlight washer system running just water, then a few squirts on the straights.

 

John

This is just to test effectivness, right? Then we can have the bespoke adjustable system, please, please, pretty please?????

F

 

The Autospeed one is well rated and cheap? I have not betrayed my cheapskate origins honestly.

 

Floyd: On my top mount in the cruise I was typically at 10-13 cent over amb.Upto 4k rpm. Did lots of experiments removing blanking plates under grills on bonnet and also did trials with splitters which may have marginally reduced temps(less than 2cent)
At WOT temps quickly went to 40+ and over 50+ if exuberance continued. On a RR run amb=7. Final temp=55cent.
FMIC fitted a couple of weeks ago. Cruise in similar conditions is amb +1to3 deg cent. Max road temp after WOT so far is 26cent amb17 and amb 14 final temp 26 after pretty hard max power run on rollers
Cannot detect reliably any increase in lag due toFMIC.
Highest temps now come from heat soak after shut down, 58cent.
About town this can take time to disipate on a warm day but on the open road it goes in a couple of mins.
Now I know a chap selling a FMIC......

 

Harvey

Great info thanks

Those are pretty impressive reasons to get a FMIC, you detect little or no lag increase so that leaves just the flow rate differences.

I typically get mid 30's + on a fast cruise so your 26's at WOT are nice. I can't justify a FMIC I'm afraid or anything significantly different to std, as I then should be buying an STI7 instead. It's a cost/benefit/depreciation ratio type of thing

F

 

Floyd: Really it is a bit like a dog chasing its tail.
I bought an STi Ver 6 Ltd so I had a good fast car I would not need to do any mods on.Only took two weeks to realise I would be far better off with a 3" D/P and exhaust. To finish it all I need is a bigger turbo but there again a fuel pump at the same time makes sense. So then H2O injection and tubular exhaust will really finish it as everything else has been changed...........
Must be some other mods for an odd bhp???