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Hi everyone.

I have a P11 (primera) with SR20DE engine running in my local rally competition.

One of the mods that I made was a Hotshot Header from JWT, but I haven't noticed the power gain they offered. There's no catalitic converter an no muffler thru the exhaust pipe.

I also own a P11 not for rally competition but with some mods. Local made header, catalitic converter but no resonators, Stillen Muffler. My feeling is that my street car rides better than the rally car, but when I purchased the hotshot header I thought it'll be better. I can't switch headers because the local rally competition norms don't allow you to (If you started with one kind of header you can not change it during the season).

Does anyone have the same hotshot header?

Does it work?
 
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Of course I know, what's your point by telling me that.
 

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I have the Hotshot header, and it definitely does work for me. I dont know what's wrong with yours....sorry.
 

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HEADERS

I cant answer if hotshot headers works or not but i will tell you some facts.
my first sr20 motor used to have a custom made 4-1 header like auebs, excaust, no cat, and worked great. then i bought the s4 cams from jwt and with a custon ECU the car felt stronger than ever.
but in a mountain, i broke my 4-1 one custom header in a rock, and i decided to buy tha last generation headers from hotshot(summer 2001). when i installed them in my car , i noticed a decrease in power, in WOT and i was very dissapointed due to the good opinions i had heard about hotshot. I then made a custom 4-1 header in the same store as previus and the car felt very strong again. so with no cat, cams and ecu the hotshot headers didnt work for me.
8 months ago , i bought a NX2000 and i put a CAI, and after that i installed the hotshot headers living the cat in place.i noticed a great increase in power, which i didnt feel with my previus car in stock form with 4-1 headers.
my opinion is
1) maybe the hotshot headers needs a cat to work properly.
2) adding mods to your car like s4 cams, ECU etc, increase the exaust gasses so much, that hotshot headers cant handle and become a decrease in power cause the gauses return back.
3) the ecu learned that you have a 4-1 header shape and works accordingly, even now you changed the old 4-1 shape with hotshot headers( 4-2-1) and that means a decrease in power.

if you find out what is going on please e-mail me back or post it cause i will soon add the S4 and ECU to my NX and hate the idea of not working properly due to headers.


GEO
 

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Butt dynos are pretty unreliable.
 

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butt dynos

i agree with you 100%. I am the first who asks about dyno measurements for everything. In this particular situation i havent a dyno to prove, but i tested the car many times taking measurements for 3,4,5 gear at WOT in the same road, same temp,same weight(my cousin) and appart from the "BUTT" dyno which i tottaly agree its not accurate, the clock times gave the same results, about the comparison of 4-1 headers vs hotshot last gen with the certain mods(CAI, EXCAUST, NO CAT, JWT S4, MODERATED ECU WHICH CRIS PRONIOS MENTIONED IN ANOTHER TREAD).
i have to mention here that in test "runs" with my cousins car and another friend of mine who we all have more than 12 years experience in modded cars ,before and after, the results were pointing to what i sayed.
finally dont forget that i am using hotshot headers in my NX2000 right now AND I AM really very impressed by the headers performance.
i just intend to put s4 and the ecu to my NX in a couple of months, allow the adlust period for both cams and ECU, dyno the car once again, then put a 4-1 headers and make a back to back comparison test using dyno numbers.
I really want this matter to be solved, thats why i posted my own experience.



GEO
 

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I did my own dyno since I put the header on. With my auto tranny, I put 97 hp to the wheels with header, intake, exhaust, pulley. Header definitely made power.
 

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i know the stock exhaust manifold on the ga16 is very poor. sr20 may have a better design. that might be why people w/ the b14 sentras (i would assume no motor swap, so ga16) are finding a lot more power than you guys... o yeah, and by saying the car is "learning" you have a specific header design... if youre worried, reset the ECU, that way it can "relearn" itself
 

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no catalitic converter an no muffler thru the exhaust pipe.
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That means that your headers are doing exactly what your old ones were doing.. except now you dont have barely ANY bakcpressure at all.. out cars need the backpressure.. i think 10PSI minimum.. taking away your cat and muffler, and straight through headers. there is no backpresure, watch, put a stock muffler on there, and watch how much more Power you will have.
 

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No muffler was taken away. just the cat. And the comparison was about hotshot headers vs 4-1 like auebs not stock ones.
i would really appreciate if mike tell us, what headers has in his 170 wheel hp monster. further more, the test of aueb headers in his moderated car or any 4-1 type header against hotshot will give a great help.


alex29
 

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Chuck, you are wrong about backpressure. Less is better in ALL cases. The old bogie about back pressure relates to carbureted vehicles. Jetting for a specific configuration is pretty unforgiving if you change that configuration. Reduce back pressure, watch your plugs melt away because the engine is now running lean. Of course, simply rejetting for the new configuration cures that ill. I had to rejet my '72 Cutlass small block when I added a single plane intake manifold. I had to rejet my motorcycle when I added a low-restriction exhaust.

Modern fuel metering systems (read mass-air-metered fuel injection) can deal with back pressure changes with great ease as long as flow remains within the fuel map's boundaries.

Our South American friend's problem is not due to a back pressure issue. It's probably a butt dyno issue, as George wrote.
 
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