VRSF N55 F15 FMIC install and review

[WOT808]

Hello,
I recently installed the VRSF race FMIC on my n55 xdrive35i F15 and it made a huge difference. IATs stay pretty flat throughout multiple gears.

I purchased the intercooler from EuroKlasse :
https://euroklasse.com/products/vrsf...b232521f&_ss=r


Pictures of the VRSF and Stock FMICs









Bringing down the stock FMIC was easy, just pop off the underbody panel, a few plastic shields unde rather fmic, the stock C clips, and 4 screws that secured the FMIC to the radiator support and the stock unit comes down.

The install wasn't bad (I've installed several FMICs on n54s). I used my jack to raise the VRSF, I then had to trim about an inch off of the plastic radiator support to get the VRSF into position (easy, did it with a razor blade). The factory style connections were a headache, though, as the charge pipes need to be precisely lined up to slide in and clip. I sanded down the inner diameter of the in/outlet on the VRSF very slightly to make the charge pipe connections easier to jam in. I wasn't interested in removing the front bumper, I may have been able to save some trimming time if I did.

Here's some install pics below:




Here's the before and after IAT on the custom E30 tune I cooked up.
Both pulls start around 76*, 2nd gear 3.5k rpm to middle of 4th gear

[phipark]

I installed an AA IC on my n54. how would this compare? I did it on ramps with bumper still on. I did have to trim the front plastic a bit but the biggest pain was lining up the charge pipe with the lower IC connector pipe that came with the IC. Sounds like the same headache.

[WOT808]

Originally Posted by phipark

I installed an AA IC on my n54. how would this compare? I did it on ramps with bumper still on. I did have to trim the front plastic a bit but the biggest pain was lining up the charge pipe with the lower IC connector pipe that came with the IC. Sounds like the same headache.

Yup, sounds about the same. The charge pipe connections were the hardest part. I did it on jack stands in my driveway too.

[M302_imola]

Appreciate you documenting this DIY and more importantly the IAT's before and after. Also, very cool you developed a E30 custom tune. Any plans to put it on the dyno? Are you running catless downpipe? I'd love to see your dyno numbers.

[WOT808]

Originally Posted by M302_imola

Appreciate you documenting this DIY and more importantly the IAT's before and after. Also, very cool you developed a E30 custom tune. Any plans to put it on the dyno? Are you running catless downpipe? I'd love to see your dyno numbers.

Had it on the dyno the other day. 399whp/493tq.
Here's vs stock flash minutes apart from each other.
Ebay DP.

[M302_imola]

Originally Posted by WOT808

Had it on the dyno the other day. 399whp/493tq.
Here's vs stock flash minutes apart from each other.
Ebay DP.

Wow! Fantastic numbers! Sounds like you know what you're doing in the tuning department. What platform tuning service are you using to build your custom tune (BM3)? Do you have a 93 octane tune as well?

[WOT808]

Originally Posted by M302_imola

Wow! Fantastic numbers! Sounds like you know what you're doing in the tuning department. What platform tuning service are you using to build your custom tune (BM3)? Do you have a 93 octane tune as well?

Thanks!
I flash via MHD. I have a BM3 account but haven't flashed via BM3 yet because MHD is just convenient. I've poked around in the BM3 editor and they have a ton of defined tables it's awesome.

I have a 93 map and also a full e85 map, haven't had dyno time with either.

[Shoop405]

Originally Posted by WOT808

Thanks!
I flash via MHD. I have a BM3 account but haven't flashed via BM3 yet because MHD is just convenient. I've poked around in the BM3 editor and they have a ton of defined tables it's awesome.

I have a 93 map and also a full e85 map, haven't had dyno time with either.

I must be running similar numbers. I have MHD Stage 2 Plus, BMS Intake, ER Charge Pipe(s), ER Catless Downpipe, VSRF FMIC.

[M302_imola]

Originally Posted by Shoop405

I must be running similar numbers. I have MHD Stage 2 Plus, BMS Intake, ER Charge Pipe(s), ER Catless Downpipe, VSRF FMIC.

Maybe or OP might be a E30 custom mapping genius I'd say you're close though anywhere from 380-400hp.

[M302_imola]

I guess I question whether an aftermarket FMIC is really needed if you're not tracking the car or beating on it. I mean I get reducing IAT's but I'm not quite sure that IAT's in the 90s would pull timing or reduce output. Someone more educated set me straight.

[devlinsky]

Originally Posted by M302_imola

I guess I question whether an aftermarket FMIC is really needed if you're not tracking the car or beating on it. I mean I get reducing IAT's but I'm not quite sure that IAT's in the 90s would pull timing or reduce output. Someone more educated set me straight.

If you don't plan to track or beat the car up, you don't need an upgraded fmic. Factory cooling systems are tested extensively in places like Death Valley, so no, you don't need upgraded cooling if the rest of your car is stock.

However, if you start modding your engine, the upgraded fmic is always the very first thing to do. Always. But I'm pretty sure that's kind of obvious and that wasn't really your question, was it?

[Shoop405]

Originally Posted by devlinsky

If you don't plan to track or beat the car up, you don't need an upgraded fmic. Factory cooling systems are tested extensively in places like Death Valley, so no, you don't need upgraded cooling if the rest of your car is stock.

However, if you start modding your engine, the upgraded fmic is always the very first thing to do. Always. But I'm pretty sure that's kind of obvious and that wasn't really your question, was it?

Originally Posted by M302_imola

Maybe or OP might be a E30 custom mapping genius I'd say you're close though anywhere from 380-400hp.

I will have to dyno and find out. Already pondering the next mod.. I like how the performance gauges in our car respond to tuning:

[Shoop405]

Originally Posted by Shoop405

I will have to dyno and find out. Already pondering the next mod.. I like how the performance gauges in our car respond to tuning:

I would also like to comment about the FMIC. I live in south Florida. It is hot and humid all year round. I didn't "need" the FMIC because I track or beat on the car. I did it for the same reasons I did the charge pipes. To improve the stock deficiencies and strengthen for increased turning down the road. I installed the FMIC before I did the charge pipes or down pipes (timing just worked out that way). I was only running stage 1 at the time. I have noticed the car running smoother and pulling more consistently in boost with the FMIC. It's like the Air Intake. Your not going to see any real noticeable performance gains but it sure helps the car breathe better.

[WOT808]

Originally Posted by M302_imola

I guess I question whether an aftermarket FMIC is really needed if you're not tracking the car or beating on it. I mean I get reducing IAT's but I'm not quite sure that IAT's in the 90s would pull timing or reduce output. Someone more educated set me straight.

Sure, 90* isn't iat isn't horrible. I'm sure you've seen delta between the stock and upgraded fmic, big difference (especially in the following gear). The stock fmic couldn't keep up with the demand of multi gear pulls. It 'works' for a 0-60 or merge situations but that's about it, after that the iats rise rapidly.

[sukhk527]

So is the general consensus in getting the VRSF or Wagner cooler to work to use the vanjen clamp on either the ER or factory lower charge pipe? I'm looking to do this soon-ish.

[M302_imola]

Originally Posted by WOT808

Sure, 90* isn't iat isn't horrible. I'm sure you've seen delta between the stock and upgraded fmic, big difference (especially in the following gear). The stock fmic couldn't keep up with the demand of multi gear pulls. It 'works' for a 0-60 or merge situations but that's about it, after that the iats rise rapidly.

All good points guys. Appreciate the insight. I'm going to do some data logging using the BM3 app and see what kind of IAT's I'm getting around town since it's hot AF in TN right now. I'll report back.

Also, did you guys go 1 step colder on the plugs? Something else I haven't gotten around to. I sure as hell don't want detonation. Guess I need to get on top of it.

[WOT808]

Originally Posted by M302_imola

All good points guys. Appreciate the insight. I'm going to do some data logging using the BM3 app and see what kind of IAT's I'm getting around town since it's hot AF in TN right now. I'll report back.

Also, did you guys go 1 step colder on the plugs? Something else I haven't gotten around to. I sure as hell don't want detonation. Guess I need to get on top of it.

Yea, let us know how your testing goes.

I run the n20 plugs.

[M302_imola]

Originally Posted by WOT808

Yea, let us know how your testing goes.

I run the n20 plugs.

1 or 2 step colder?

[Shoop405]

Originally Posted by M302_imola

1 or 2 step colder?

97506 plugs. Burger Motorsports have them for $85.

If I was going to do it again, I would probably get the Wagner.

[WOT808]

Originally Posted by M302_imola

1 or 2 step colder?

I've seen one step colder on one site, another site says they're similar to the stock plug heat range. I changed plugs because I was experiencing a slight misfire post shift. Turns out my AFRs were dipping too low (stft goes to 0/open loop , n55/s55 thing) causing the stutter. Fine tuning the fuel scalar is pretty important as it resolves large deviations in actual AFR vs target in these open loop situations.

[WOT808]

Originally Posted by Shoop405

97506 plugs. Burger Motorsports have them for $85.

If I was going to do it again, I would probably get the Wagner.

Why wagner?

[sukhk527]

Curious to know why Wagner as well. Seems like both would have fitment issues without the clamp fix.