Stillen Headers + Berk HFCs self-install report

K20A2_S · 03-27-2009, 06:04 PM

^^I'm curious and looking foward to seeing a dyno from a third party not related to a company dyno a 370 with

Intakes
Header, HFC, Y-pipe and stock or aftermarket exaust.

Will tuning be an issue with that setup? obviously it will optimize your mods, but is it necessary to keep the a/f at safe levels? I guess hookind up an a/f gauge tapped into teh header will be the only real way to tell....

wstar · 03-27-2009, 08:24 PM

I don't think it will be a "safety" issue from what I've heard (and observed so far), but I definitely do think a proper tune will be in order once all the major parts are on. My plan at the moment is Stillen's G3 intake, headers, and cat-back, with the Berk HFCs. However, right now only the headers and HFCs are installed. The car will be dyno'd and tuned once it's all in place.

I got under the car just now for the first time since getting back to Houston (with floor jacks, etc - what a pain

). I went ahead and retorqued what I could easily reach (basically everything but the actual header<->engine nuts), and found a couple that turned decently (half a turn on one, a bit more than a quarter on the other). Test drove it after, and much of the rasp is gone. What rasp is left now only kicks in under more demanding circumstances (full throttle or near to it and 5k+ rpms). Re-torquing the header bolts will probably get rid of the rest.

I also got my first good look at the cats during that, and the metal has discolored significantly now that it's been subjected to exhaust heat. They had a plain stainless steel color on install, they're now a deep burnt copper to also dark brownish all over. I expect this is normal, and that it probably explains the smoking during the first warmup. Someone let me know if you don't think so

Later in the weekend I'll probably team up with someone to have more jacks and jackstands available and get under there to retorque the header bolts.

(Oh, and with less annoying rasp I was willing to push the car a little further on this drive, and my patented Butt Dyno definitely now says it feels the difference, at least in the upper rpm range).

wstar · 03-28-2009, 08:54 PM

Final update on this. I've re-torqued everything and put in the new O2s. The header bolts were fine. The only bolts that really seemed like they needed a re-torque were the header<->cat flange bolts (I guess the gasket Berk supplies kinda burns in and gets thinner once heated). There are still a couple of points along the RPM range where I'm getting some rasp or vibration of some kind, but I've eliminated the possibility of any leaks. I think it's just the stock catback not coping so well with the new headers/cats. Other than when it hits those vibration points, it sounds awesome so far. I'm sure everything will get worlds better with the Stillen catback in place.

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03-27-2009, 06:04 PM	#1 (permalink)
K20A2_S Base Member Join Date: Mar 2009 Location: Houston Posts: 67 Drives: 04 RSX Rep Power: 274	^^I'm curious and looking foward to seeing a dyno from a third party not related to a company dyno a 370 with Intakes Header, HFC, Y-pipe and stock or aftermarket exaust. Will tuning be an issue with that setup? obviously it will optimize your mods, but is it necessary to keep the a/f at safe levels? I guess hookind up an a/f gauge tapped into teh header will be the only real way to tell....

03-27-2009, 08:24 PM	#2 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3596	I don't think it will be a "safety" issue from what I've heard (and observed so far), but I definitely do think a proper tune will be in order once all the major parts are on. My plan at the moment is Stillen's G3 intake, headers, and cat-back, with the Berk HFCs. However, right now only the headers and HFCs are installed. The car will be dyno'd and tuned once it's all in place. I got under the car just now for the first time since getting back to Houston (with floor jacks, etc - what a pain ). I went ahead and retorqued what I could easily reach (basically everything but the actual header<->engine nuts), and found a couple that turned decently (half a turn on one, a bit more than a quarter on the other). Test drove it after, and much of the rasp is gone. What rasp is left now only kicks in under more demanding circumstances (full throttle or near to it and 5k+ rpms). Re-torquing the header bolts will probably get rid of the rest. I also got my first good look at the cats during that, and the metal has discolored significantly now that it's been subjected to exhaust heat. They had a plain stainless steel color on install, they're now a deep burnt copper to also dark brownish all over. I expect this is normal, and that it probably explains the smoking during the first warmup. Someone let me know if you don't think so Later in the weekend I'll probably team up with someone to have more jacks and jackstands available and get under there to retorque the header bolts. (Oh, and with less annoying rasp I was willing to push the car a little further on this drive, and my patented Butt Dyno definitely now says it feels the difference, at least in the upper rpm range).

03-28-2009, 08:54 PM	#3 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3596	Final update on this. I've re-torqued everything and put in the new O2s. The header bolts were fine. The only bolts that really seemed like they needed a re-torque were the header<->cat flange bolts (I guess the gasket Berk supplies kinda burns in and gets thinner once heated). There are still a couple of points along the RPM range where I'm getting some rasp or vibration of some kind, but I've eliminated the possibility of any leaks. I think it's just the stock catback not coping so well with the new headers/cats. Other than when it hits those vibration points, it sounds awesome so far. I'm sure everything will get worlds better with the Stillen catback in place.