Zeezeebaba Posted June 26, 2015 Share Posted June 26, 2015 How common a problem is it that hesitation occurs about 3k revs with HFCs fitted and no remap to compensate for resonance. I've read that some people have issues but was wondering if the set up you have post cats makes a difference? I have a Miltek fitted post cats that appears to be similar in design to the standard OEM set up so before fitting the Berk HFCs I have on order it would be nice to ascertain if a remap is a must. Quote Link to comment Share on other sites More sharing options...
Ekona Posted June 26, 2015 Share Posted June 26, 2015 I'd only remap after all breathing mods are done, else you're wasting your money. Quote Link to comment Share on other sites More sharing options...
Zeezeebaba Posted June 26, 2015 Author Share Posted June 26, 2015 Oh for sure that would be the plan, plenum spacer etc. I was just trying to ascertain if I could get away with not doing the map at all. I have my beady eye on a Jag XK at the moment as my left knee is giving me trouble. Quote Link to comment Share on other sites More sharing options...
Ekona Posted June 26, 2015 Share Posted June 26, 2015 Ah, ok. Unless you experience any issues yourself, I wouldn't bother; It seems to be very car-dependant on whether any niggles crop up. Then again, I wouldn't fit HFCs without a remap as you're still wasting your money, unless you're desperate for that little extra noise over the regular cats. A decent exhaust and intake would do a better job with the noise than the HFSc will though. 1 Quote Link to comment Share on other sites More sharing options...
Zeezeebaba Posted June 26, 2015 Author Share Posted June 26, 2015 All I'm interested in is getting the CEL off tbh I took the standard cats off as they were rusty and blowing. Replaced them with second hand standard cats only to find one of them (bank 2) was shot.Sensors replaced just in case but diagnostic confirmed the cat was shot. So I figured HFCs were cheap and may assist a targeted sale as all the new owner would need to do is the breathing mods etc. Quote Link to comment Share on other sites More sharing options...
Ekona Posted June 26, 2015 Share Posted June 26, 2015 Couple of O2 extenders should do the trick. If they don't then just get taller ones made or stick two extenders together. 1 Quote Link to comment Share on other sites More sharing options...
jimboy2 Posted June 26, 2015 Share Posted June 26, 2015 As you may have seen, I have just had berks fitted and I have a hesitation at around 3k. It's horrible! Need a remap done soon really. It drastically changes the sound of the car too. I have a cobra and it's really loud now! Quote Link to comment Share on other sites More sharing options...
Zeezeebaba Posted June 26, 2015 Author Share Posted June 26, 2015 Do you have a y pipe as part of your post cat system? 1 Quote Link to comment Share on other sites More sharing options...
Zeezeebaba Posted June 26, 2015 Author Share Posted June 26, 2015 The miltek is very quiet with the standard cats in place. I suppose the only definitive answer as Ekona says will be to fit them and find out.I have a sneaking suspicion though that the miltek system won't create an issue unless someone on here has experience of it. Quote Link to comment Share on other sites More sharing options...
jimboy2 Posted June 26, 2015 Share Posted June 26, 2015 Do you have a y pipe as part of your post cat system? Yes I do Quote Link to comment Share on other sites More sharing options...
Bodyboarder81 Posted June 26, 2015 Share Posted June 26, 2015 I run the miltek with art pipes ( decats) and it's still very quite even with the charger on . Quote Link to comment Share on other sites More sharing options...
dajw Posted June 26, 2015 Share Posted June 26, 2015 I run the miltek with art pipes ( decats) and it's still very quite even with the charger on . I had straight through decat pipes on my 370z, and it was loud. The motordyne art pipes are a lot quieter than regular decats (on my car at least). Quote Link to comment Share on other sites More sharing options...
Brummiestormer Posted June 26, 2015 Share Posted June 26, 2015 Maybe it's just me but i can't see why all the trouble and expense over so little gain overrall Quote Link to comment Share on other sites More sharing options...
Brett350z Posted June 27, 2015 Share Posted June 27, 2015 I have just paired Berk HFC's to my Miltek catback system and luckily (100 miles on) have no CEL light. The O2 sensor was fitted to the taller bank on the HFC. When cold the noise is very raspy but when all is warm the rasp is still present, characteristic of HFC's but you still get that distinct low burble of the Miltek. It's a lovely tone if I am honest and the overall volume for a daily drive is perfect, no drone and the pops on runover are lovely to hear. I hope after a few hundred more miles they will start to sound even better. I have noticed a slight loss of torque in the midrange but it pulls harder towards the redline. With premium fuel Ive noticed no hesitation in the rev range so subsequently wont be going for an UPrev remap. As Ekona mentioned I think it is very car dependant. 1 Quote Link to comment Share on other sites More sharing options...
Zeezeebaba Posted June 27, 2015 Author Share Posted June 27, 2015 That's what I wanted to hear Brett nice one. Quote Link to comment Share on other sites More sharing options...
Bodyboarder81 Posted June 27, 2015 Share Posted June 27, 2015 I don't really see the point in HFC if you're not going to remap ( unless for noise reasons) as you're not going to gain any more power at all with out a uprev remap . Quote Link to comment Share on other sites More sharing options...
Richie94gts Posted June 27, 2015 Share Posted June 27, 2015 I've got the cobra non-res exhausts, which sounds really nice but I don't get any popping. It sounds like its almost there though. Any idea which would give me better pops and bangs at this stage - y-pipe or hfc? Presumably hfc as ypipe would only give slight improvements in flow? Quote Link to comment Share on other sites More sharing options...
HAMLNJ Posted June 27, 2015 Share Posted June 27, 2015 Without a remap I found decats helped with throttle response. Now I have the cats back on I feel a loss in grunt! Quote Link to comment Share on other sites More sharing options...
MDMetal Posted August 6, 2015 Share Posted August 6, 2015 I have berk hrc's with no remap and sooner or later the light always comes back on. I ran with spacers for a bit but didn't see any real difference, the spacers were about 7cm deep. Not sure if that's big or small! It's a bit of a pain really Sounds nice though! Quote Link to comment Share on other sites More sharing options...
Bems Posted August 6, 2015 Share Posted August 6, 2015 I fitted berk HFCs with the intention being for the exhaust to follow. I also have Takeda short ram intakes. For me there is occasional hesitation but it's not often & it only happens if I'm pushing on. I don't have any cel lights, never had that problem but it may differ from the DE as mine is an HR model. Quote Link to comment Share on other sites More sharing options...
Dashurik Posted August 6, 2015 Share Posted August 6, 2015 (edited) Have berks hfc and remap...i ddint noticed any difference in power after remap,may be i got used to the car a lot!..berks will definitely add more noise and bring cel on eventually.. i personally wouldn't do breathing mods and remap if I had a choice to do it now! Think money could be spent better elsewhere like: suspension or brakes..if you want more power then turbo or supercharger anything else is just for show off....So moral is:Im showing off..:-) Edited August 6, 2015 by Dashurik Quote Link to comment Share on other sites More sharing options...
Dynamic Turtle Posted August 6, 2015 Share Posted August 6, 2015 As ekona said make you sure get absolutely everything done - intakes, filters, plenum, manifolds, cats and exhaust etc before Uprevving. Power increases will be subtle along with throttle response benefits, but the noise will be epic and you'll have a sharp car to play with afterwards. Berk + Miltek is a good combo - no motorway booming but great rasp under WOT. Currently running Berk/Cobra on my 370ZN and it's much louder. Not necessarily a good thing for long motorway trips... Quote Link to comment Share on other sites More sharing options...
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