[sqwinny]

Hello Bimmerpost,

in pursuit of going FBO stage 2 (320-380whp), I am doing some research and trying to decide what IC and volume size to go with. Maybe I'll throw a MHI turbo on the car eventually but not anytime soon. I just want to do this once.

Considering the n20/n26 won't go over 430whp unless you do a full rebuild, what would the proper size IC be? From what I understand thus far, a standard 5" intercooler should be fine as under 400whp is stage 1 for the n54/n55/b58 motors. No plans to use meth/water injection. Just regular spirited driving on the street as an occasional track day just to have some fun. This n20 doesn't have plans to be a stripped track car by any means. I don't see a reason for the huge Dinan or 7" competition VRSF at this time. Cost does play a part but I dont want to pay for more if I can't use it without a rebuild and at that time to get over 400whp it makes sense to buy another vehicle (n54/n55/b58) due to ROI.

I have yet to find any logs of cars pulling timing with the n20 with a stage 2 and any specific intercooler.

From the options I have looked at there are the following:

VRSF 5 stepped
Wagner Evo 2/3
Evolution Racewerks
CSF intercooler
Phoenix intercooler

All of our vendors here sell these items. Thoughts?

[mike@x-ph.com]

I recommend a 6" intercooler for a stage 2, even if you do not plan on tracking the car. Options include Wagner EVO II, VRSF 6.5" Competition , CSF & Evolution Racewerks

[AsianBill]

Not sure where you got the numbers from but the n20/n26 requires rebuilds at 350 wheel hp/torque. Any of those intercoolers you listed will do the job. Vrsf stepped is a popular option from what I've seen on here. Personally I'm going with the g plus once it is back on amazon(cheapest of the bunch but from reviews it seems to do the job fine), or I'll be going with vrsf stepped.

[sqwinny]

Originally Posted by mike@x-ph.com

I recommend a 6" intercooler for a stage 2, even if you do not plan on tracking the car. Options include Wagner EVO II, VRSF 6.5" Competition, CSF & Evolution Racewerks

Thanks, Mike. I've been digging into this thread on the M2 part of our forums "THE ULTIMATE Intercooler Thread - What to Look For Before Buying an FMIC"

https://f87.bimmerpost.com/forums/sh....php?t=1458121

My brain is making me try to figure out IC size with n20 vs n55/s55. Either way, an order will come from you. I'll PM you when I make my decision.

Originally Posted by AsianBill

Not sure where you got the numbers from but the n20/n26 requires rebuilds at 350 wheel hp/torque. Any of those intercoolers you listed will do the job. Vrsf stepped is a popular option from what I've seen on here. Personally I'm going with the g plus once it is back on amazon(cheapest of the bunch but from reviews it seems to do the job fine), or I'll be going with vrsf stepped.

Perhaps/perhaps not. I might read a little higher than others as I am 6MT instead of auto. With this whole COVID lockdown I was planning on bolting everything up, grab a baseline run of stock with IC/Downpipe/93 gas, conduct 3 pulls, allow the car to cool down, flash bm3 stage 2, report findings as it seems little/no one has reported them. I'm willing to take the bullet for future research on the platform as it spikes my own curiosity too.

[alohasurftoad]

the best is, Wagner Evo II Competition, tube fin, light, best throttle response(least pressure drop), or 2nd best ATM
https://f30.bimmerpost.com/forums/sh...30&postcount=4
https://f30.bimmerpost.com/forums/sh....php?t=1518971
https://f30.bimmerpost.com/forums/sh....php?t=1623267
https://f30.bimmerpost.com/forums/sh...2&postcount=20

[mike@x-ph.com]

Originally Posted by sqwinny

Thanks, Mike. I've been digging into this thread on the M2 part of our forums "THE ULTIMATE Intercooler Thread - What to Look For Before Buying an FMIC"

https://f87.bimmerpost.com/forums/sh....php?t=1458121

My brain is making me try to figure out IC size with n20 vs n55/s55. Either way, an order will come from you. I'll PM you when I make my decision.

[Fade_The_Public]

Originally Posted by sqwinny

Hello Bimmerpost,

in pursuit of going FBO stage 2 (320-380whp), I am doing some research and trying to decide what IC and volume size to go with. Maybe I'll throw a BMI turbo on the car eventually but not anytime soon. I just want to do this once.

Considering the n20/n26 won't go over 430whp unless you do a full rebuild, what would the proper size IC be? From what I understand thus far, a standard 5" intercooler should be fine as under 400whp is stage 1 for the n54/n55/b58 motors. No plans to use meth/water injection. Just regular spirited driving on the street as an occasional track day just to have some fun. This n20 doesn't have plans to be a stripped track car by any means. I don't see a reason for the huge Dinan or 7" competition VRSF at this time. Cost does play a part but I dont want to pay for more if I can't use it without a rebuild and at that time to get over 400whp it makes sense to buy another vehicle (n54/n55/b58) due to ROI.

I have yet to find any logs of cars pulling timing with the n20 with a stage 2 and any specific intercooler.

From the options I have looked at there are the following:

VRSF 5 stepped
Wagner Evo 2/3
Evolution Racewerks
CSF intercooler
Phoenix intercooler

All of our vendors here sell these items. Thoughts?

I have the CSF FMIC and I'm in love with it. Out of the box, it just looks amazing. The polish they put on it is so sharp looking that when installed, it makes the car look classy AF.

[BEM-S4]

AA makes a nice one as well, got mine from Mike been very happy with it. Worth adding to your list.

[mike@x-ph.com]

Originally Posted by BEM-S4

AA makes a nice one as well, got mine from Mike been very happy with it. Worth adding to your list.

Congrats

[sspade]

GPlus

[Gen13 F36]

Pushing the N20/26 to the limit, good luck

+1 to Mike's choices

[sqwinny]

Originally Posted by Gen13 F36

Pushing the N20/26 to the limit, good luck

+1 to Mike's choices

I think I'll be ok in terms of "limits". Just FBO Stage 2 with complimentary mods. Intake/Inlet pipe/IC/diverter valve/Chargepipes/catless DP/HPFP/Stage 2 tune. More or less just want to beat/match a Stage 1 n55 just to put a surprise on an unexpecting someone's face while having fun.

Currently have downpipe and stage 2 tune. researching pipes and ordering those to replace the rubber ones with "performance maintenance" duties, researching intercoolers, and will piece everything little by little. Don't see any reports of the 6MT not holding the power, nor the stock clutch with all mods and stock turbo.

If that doesn't work, the only thing less is a big turbo to increase hp/tq but at smaller boost levels. A upgrading to a bigger turbo which increases power but shifts the tq curve slightly should protect the bottom end moving more air with less boost. At least that's what I have read/understand thus far

[Gen13 F36]

Originally Posted by sqwinny

If that doesn't work, the only thing less is a big turbo to increase hp/tq but at smaller boost levels. A upgrading to a bigger turbo which increases power but shifts the tq curve slightly should protect the bottom end moving more air with less boost. At least that's what I have read/understand thus far

I don't know about protecting the bottom end... I don't think that's how it works.... shifting tq curve to where: towards the higher RPM , where the engine component( valve, rods and piston )move the fastest will protect the bottom end

Still the same intercooler mention above is my top choices. I'll be getting one soon too.

[cedaj]

Stretched rods because of high tq low rpm situations, shifting the torque curve will help with keeping things safe

[sirch]

Originally Posted by alohasurftoad

the best is, Wagner Evo II Competition, tube fin, light, best throttle response(least pressure drop), or 2nd best ATM
https://f30.bimmerpost.com/forums/sh...38;postcount=4
https://f30.bimmerpost.com/forums/sh....php?t=1518971
https://f30.bimmerpost.com/forums/sh....php?t=1623267
https://f30.bimmerpost.com/forums/sh...8;postcount=20

[QUOTE=alohasurftoad;25971537]the best is, Wagner Evo II Competition, tube fin, light, best throttle response(least pressure drop), or 2nd best ATM


I have not seen any bench flow testing on any intercoolers showing bench flow rates and pressure readings pre and post. Do you have this information or is this a subjective statement. If you have this information it would be really interesting to see if you can post your source.

[alohasurftoad]

Originally Posted by sirch

I have not seen any bench flow testing on any intercoolers showing bench flow rates and pressure readings pre and post. Do you have this information or is this a subjective statement. If you have this information it would be really interesting to see if you can post your source.

i'm guessing you didn't look through the threads I linked. most of my statement is based on this test by FaRKle!
https://f30.bimmerpost.com/forums/sh....php?t=1518971

i don't know of any unbiased flow bench test between intercoolers that exist. there are, "ours is better than yours", manufacturers claims which i take "like a grain of salt" and a lot of feedback from members with different intercoolers based on their "butt dyno" and typically biased because that's what they've bought, i'm no different.

whether it be intercoolers or other mods for engine, suspension, wheels, etc., you'll find little it way of proper comparison tests because it's not realistically(time and cost) feasible. most(not all) statements comprised of reviews and opinions are subjective by nature.

[sirch]

I just get tired of hearing this intercooler is the best, show me the numbers. I have manufacture 1000's of intercoolers in the past. If any manufacture reading this post wants they can perform a bench flow of there intercooler. I did this with competitors intercoolers vs mine to show the flow rates and pressure pre and post. I stopped making intercoolers years ago, so please do not get the impression I going for the angle. If a vendor wanted to perform this test they could call around to machine shops and I am sure someone would let them perform the bench flow testing, that is how I did mine. I do not think this is done because the difference, or lack there of between intercoolers would be surprising.