Intercooler performance

[Navi]

That does make sense about heat from the engine components throwing off air temp readings.


Also, I took another look at the data from APR, since it is the only "real" data I have seen.... They did 6 consecutive runs, with 30 second intervals.

Their data shows that IAT temps with their intercooler barely change. From beginning of the first run to the end of the 6th run, temp increases by 7 degrees (C)

The crazy part is that this temp increase over the 6 pulls does not happen during the run. It happens in the 30 sec interval between the pulls!


With the stock IC, temps jump significantly during the pull...which is what we would expect.

I'm including a simple spreadsheet...One detail that stuck out to me is that the stock IC cools down 22 degrees (C) in the 30 second interval between runs. But the first run gained 28 degrees. If a longer interval was used, the results would be more favorable for the stock intercooler.

So based on this data, "heat soak" is only a thing if you are doing full pulls every 30 seconds or less. That is quite a lovely piece of data, isn't it?


In this data, "heat soak" accounted for 17 degrees (C) temp increase on the 6th run. But there was another 25 degree temp increase due to compressing the intake air. So 40% is heat soak, and 60% is compressing the air. Again, with a longer interval, that heat soak contribution would be essentially zero.


Now, for some math! First run. Assuming PSI numbers that are easy to work with...

43 degree (C) air @ 14psi (absolute) = 1.06363 kg/m^3
71 degree air @ 28psi = 1.9542

Intake Air density at 28psi is 1.83x

41 degrees @14psi = 1.0704
41 degrees @28psi = 2.1408

Intake air density at 28 psi is 2.00x

On the first run, the stock IC lost 17% air density compared to the APR (at the same PSI...). That is losing something like ~14% HP.

On the final run, the APR IC has 11% higher air density than the stock IC.

And their data shows a 9% gain in HP on the last run, which is surprisingly close to the 11% difference in air density I casually/haphazardly calculated..


And...another topic for discussion...it looks to me like the APR Stage 2 dyno charts are only possible with their intercooler. (I wanted to ask, but never did...) They do not say anywhere that the IC is required to reach the 304hp peak power number. And the tuner I went to didn't think the IC was a big deal, saying he would rather ad turbo noises than do the IC...

But if their IC data I'm playing with is correct, showing a peak of 298hp after a 3% loss in air density (due to 9 degree temp increase)...that means the advertised 304hp is only possible with their IC...That means I'm not getting anywhere close to 300hp...more like 260!

Grrrrr..... I love the new clutch I just got, but with the DP and tune it doesn't really feel like a lot more power than I had before....I guess now I know why it doesn't feel like 304hp!

that's what I was going to say

 

[anotero]

100% with you on the importance of intercooler on these cars. I think a few pages back I threw out the air density loss comparison as well. Plus the ECU is pulling quite a bit of ign timing with high IATs. Double whammy of a power killer.

Would this mean that unless I'm hooning and tracking, heatsoak for a stock location IC is not a big issue?

 

[El_bigote_AJ]

Would this mean that unless I'm hooning and tracking, heatsoak for a stock location IC is not a big issue?

Driving to and from work while shifting before 3k... sure one could say it’s useless.

 

[drrck]

I'm pretty sure I posted this before, but if you are tracking, the IC makes a massive difference as one would suspect. This is my car on the same track same setup other than IC with my IS20 before I swapped to IS38. I have the .csvs for these runs as well if anyone wants to see them let me know.

 

[aaronc7]

Would this mean that unless I'm hooning and tracking, heatsoak for a stock location IC is not a big issue?

I don't hoon around everywhere or do long WOT pulls all the time.....but when I finally do hoon on it a bit, it was quite underwhelming on stock IC because by the time I hit 3rd-4th-5th gear you can really feel the car fall on its face and run out of power due to heatsoak. If you don't go WOT often or never go WOT more than 5 seconds at a time or whatever then yeah.....IC upgrade probably not super worthwhile.

As far as high IATs driving around normally in the summer...yeah I guess that's just expected based on the fact I always have the AC blasting and it's sandwhiched between two other heat exchangers. It does make IAT seem pretty high just cruising around, but seems to work quite well when you get on it and I can always turn off the AC too. It is what it is, not worth worrying about too much.

 

[gti330ex]

I'm pretty sure I posted this before, but if you are tracking, the IC makes a massive difference as one would suspect. This is my car on the same track same setup other than IC with my IS20 before I swapped to IS38. I have the .csvs for these runs as well if anyone wants to see them let me know.

Wish i had a log of my stock intercooler at stage1. If you don't mind can you send me your .csvs or link to your datazap? I'd love to break it down and do some comparison to my 10 lap log (posted few pgs back)

I just broke down my lap 2 & lap 9 logs to how you have it and i'm getting 27/39 & 29.5/41 avg/peak over ambient at 79/80 ambient. Running CTS FMIC with APR's stage1 on stock plugs. This was my first time out on the track (session 3) - and to say the least.. I was pretty disappointed at how much power was robbed and how the PP GTI performed overall, on MPSS rubber.

Main straight goes for about 12-13 sec (which is about half that (beg & end) on these logs as i kept them to "one" lap)

Lap 2:
https://datazap.me/u/borispele/log-1590678932?log=0&data=1-3-5-7-11

Lap 9: IAT running about 5F hotter compared to lap 2 during WOT runs. There was one WOT line where IATs were identical between the two laps, which i find odd.
https://datazap.me/u/borispele/log-1590681065?log=0&data=1-3-5-7-11

Would be nice to see if GTI Jake has logs of his FMIC unit @ stage2 and others that regularly track their cars.

 

[anotero]

I don't hoon around everywhere or do long WOT pulls all the time.....but when I finally do hoon on it a bit, it was quite underwhelming on stock IC because by the time I hit 3rd-4th-5th gear you can really feel the car fall on its face and run out of power due to heatsoak. If you don't go WOT often or never go WOT more than 5 seconds at a time or whatever then yeah.....IC upgrade probably not super worthwhile.

As far as high IATs driving around normally in the summer...yeah I guess that's just expected based on the fact I always have the AC blasting and it's sandwhiched between two other heat exchangers. It does make IAT seem pretty high just cruising around, but seems to work quite well when you get on it and I can always turn off the AC too. It is what it is, not worth worrying about too much.

Sounds good. Which IC are you running?

 

[aaronc7]

Sounds good. Which IC are you running?

APR. I was between APR and IE mostly. APR had a sale going on, so I got APR. I think unitronic is a good value too. Sure it's not "the best", but it's a few hundred dollars less. Nothing wrong with it. I was also looking at BMS as a budget option. But they weren't ready yet when I was ready to make the purchase. Bottom line there's lots of good options out there, I wouldn't get hung up on "what's the best", especially for stock turbo/mild builds. Going down the road of what's best and chasing every last hp/every last 0.1% of efficiency is a slippery slope lol.

 

[mk6'12gti]

Just throwing another fmic option out there. Found this today while browsing

 

[Diggs24]

Wolf SPecial

 

[mk6'12gti]

Also is anyone running a HG motorsports ic? German made so you would think quality should be good. Pricing isnt horrible either.

 

[MonkeyMD]

Wolf SPecial

It still has a hood though.

 

[GTI Jake]

Had an R over today.

 

[drrck]

Wish i had a log of my stock intercooler at stage1. If you don't mind can you send me your .csvs or link to your datazap? I'd love to break it down and do some comparison to my 10 lap log (posted few pgs back)

I sent you a DM with the files.

 

[billbadass]

that looks epic Jake!

as I have thought about this more I think makes a lot of sense to just use what is proven also, at least one FWD GTI has gone >140mph in the quarter mile on APR intercooler and then Ed has been low low 10s at >130mph in his Golf R with AMS intercooler and made >600whp, so until I see someone at the track putting down faster or similar track times on other intercoolers seems like a pretty easy decision to go with either APR or AMS in my mind