OK im redoing my exhaust system on my db1 and want everything bolt on. previous owner had a custom chopped setup on there.
anyhow i already bought a new bolt on catback exhaust and now need to change the header and install a test pipe.
i need help on what 4-1 header to buy since i have a b20 longblock with a b16 head and will the adjustable
test pipe work to fill in the gap since i have a db1
also whats a good 2000f clear coat to put on the full exhaust system?
??
If you’re buying ebay knock off parts why go through all the trouble to have everything bolt on? The quality of fitment for those parts is poor at best. Mixing and matching them will be a headache. Why not just get whatever you neeed welded up at a shop and just tell them where you want the flanges to be?
I’d stay away from a 4-1, they hang really low, so unless you’re stock height it’s pretty much guaranteed that you’re going to smash it all to hell in no time. I’d recommend the PLM TA or Skunk2 Alpha. You’ll want to check clearance in regard to the b20 to confirm they’ll fit, but I think the b20 has the same deck height as a b18c and those headers fit b18c blocks so I think you’d be fine. As for a test pipe, they’re all pretty much the same. I think the guy who sells the PLM’s can put a package together for you. Personally I’d recommend an actual catalytic converter instead of a test pipe unless this is a dedicated race car.
because bolt on is better and i can install it myself.
ive never heard of people having prbs with bolting them up even on all the reviews ive read.
4-1 has a better flow. i have a 4-1 install from previous but its cut and non-polish.
which is why i want to change it. i have alot of clearance sine the car is on 17s now with a 2in drop.
just looking to order the right size header due to the longblock.
[QUOTE=bendogz;2331118]4-1 has a better flow. i have a 4-1 install from previous but its cut and non-polish.
which is why i want to change it. i have alot of clearance sine the car is on 17s now with a 2in drop.
just looking to order the right size header due to the longblock.[/QUOTE]
Where’s your info that 4-1 has better flow? The 4-1’s you’re looking at are good but not the best, they’re copies of the ITR 4-1 which is not the best header in the world. Are you looking for midrange or high end or overall? Most of the header tests I’ve seen have not put the 4-1 anywhere near the top of the results and most of the time the Toda is at the top or near the top (this is what the PLM TA is modeled after).
http://ipgparts.com/blog/b-series-header-test-results/
http://honda-tech.com/all-motor-naturally-aspirated-44/budget-header-showdown-replica-headers-vs-skunk2-alpha-1-8l-dyno-test-3005484/
Maybe your larger block makes enough of a difference here, but I still wouldn’t opt for the 4-1 and would try to get a 2.0l specific header - one of the “big tube” ones.
If you’re getting a 4-1 off ebay then you’re just taking a risk. They aren’t that bad but I had one for awhile and it ended up cracking. If you want a quality 4-1 I’d look at the DC sports JDM ITR header, it’s a quality piece.
thanks on the help.
from what ive read up the 4-1 has less back pressure and more high end pressure
http://www.redline360.com/garage/4-1-vs-4-2-1-headers-what-is-the-difference-what-makes-more-power
4-1 headers are designed so that all 4 exhaust pipes merge into one. In most dyno tests, this produces the most top end power since it usually offers the best flow characteristics for the engine at high engine speeds. 4-1 headers usually move the power band up, which makes the bottom of the RPM band feel a bit weak and the “seat of the pants” feel might not be as strong as a 4-2-1 header. However, dyno tests have show that at low RPM there is very little difference in power. The 4-1 headers usually have less back-pressure than the 4-2-1 header and customers have stated their cars seem louder at high RPM with the 4-1 headers. Most headers that are street legal or CARB legal are usually of the 4-2-1 design but there are exceptions.
I’m aware of the theoretical differences but IMO what’s important are results. In my experience those typical differences people discuss about parts don’t always hold true when you actually start testing the parts. Exhaust size is a great example. People used to say that you didn’t want to go very large for fear of loss of back pressure which could actually make you lose power. But what’s been happening now is people have been using increasingly larger and larger exhaust piping diameters and the results are more power.
I’m not saying you’re wrong, just saying that if it was me I’d be researching actual dyno tests for an engine similar to mine and use that data to pick a header.
You can use the hytech reps 4-2-1 they flow pretty good, and they tuck in under the oil pan pretty good.
You might run into fitment issues like clearing your oil pan and cross member.
Honestly a 2 piece dc header will be fine.
I had one on my b18c type r engine and it was great.
I used an rmf narrow on my old b20 with hydro b16 trans setup