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Serious Question about HKS Down Pipe

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Old 10-28-2002, 10:09 PM
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Long story, but I had the following relevant mods:



Highflow cat, intake, HKS DP, HKS catback, power FC, Blitz SMIC.



I dynoed at 266 with 12 lbs of boost. My best time with a 2.03 60' was 13.0 @ 107 that I could not repeat. I would do regularly 13.15 to 13.6. I'm not talking about going to the drag strip once or twice. I went every wed since July 3 for 3 to 4 runs each night. OK....



I took my car back to ricks rotary performance to have a Mid pipe, 1200 CC secondary injectors, highflow fuel pump put in my car. Heres the deal...I ran at the track 13.3 to 13.75. Turning up the boost does little to improve my time. My car sounded as quiet as it did with my midpipe. I could tell almost no difference in my car. Keep in mind that my engine has very good compression and is fairly new.



My trap did not go up, it actually dropped a little or remained the same. I believe the base maps that were downloaded were very rich. Rick does not have a dyno so he referred me to Shiv at shivnutuning. I spoke with someone there who pointed to my downpipe (HKS with a crimp in it) and said he believes thats the problem with my car.



What do you guys think? I mean...any evidence that there is a difference in downpipes? Do you guys agree or disagree?





Thanks!
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Old 10-28-2002, 10:34 PM
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i would look in to getting it dynoed again sounds to me like its a littel rich also i would invest in a egt gage then you can se how the car is running
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Old 10-29-2002, 11:05 AM
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i dont think the dp is you problem. dyno the car and see where you are. actually you should dyno with and without the midpipe.



mike
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Old 10-29-2002, 11:10 AM
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I'd dyno the car to get hp and also a/f ratio readings. If you want to spend some money dont by a egt, buy a wide band.



I wouldnt worry about either, just go to the dyno and check it to make sure your safe. If you have decent a/f ratios and your still low on power get a compression test.



BTW - is that HKS catback one of the kind with a silensor in the back that you can pull in and out??? If so thats probably your prob if the silensor is in place.



STEPHEN
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Old 10-29-2002, 11:11 AM
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if anything it sounds to me like you might have a turbo problem whether it be something with yours or the control system....
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Old 10-29-2002, 12:07 PM
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are you running the sequential system?



anyway, look at the thread regarding downpipes just below this one. i was talking to a guy named tofu86. we had the hks DP on the shop car, as well as mine, and found it NOT to flow as well. the mounting area is much flatter and crimped where it comes off at the manifold......



i can hook you up.



but really though. have your car looked into by a shop with a wide band like the others said, and see what your a/f ratios are. too much fuel can be VERY power robbing.....



louis
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Old 10-29-2002, 02:01 PM
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Originally Posted by j9fd3s' date='Oct 29 2002, 09:05 AM
i dont think the dp is you problem. dyno the car and see where you are. actually you should dyno with and without the midpipe.



mike
Without the Mid pipe I dynoed at 266. that was with a HF cat. on 12 PSI stock injectors.



My car has good compression engine has 35K, test was done last May.



DAvid
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Old 10-29-2002, 02:44 PM
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Originally Posted by ZeroBanger' date='Oct 29 2002, 12:01 PM
[quote name='j9fd3s' date='Oct 29 2002, 09:05 AM']i dont think the dp is you problem. dyno the car and see where you are. actually you should dyno with and without the midpipe.



mike
Without the Mid pipe I dynoed at 266. that was with a HF cat. on 12 PSI stock injectors.



My car has good compression engine has 35K, test was done last May.



DAvid[/quote]

thats kinda low. i did 245wrhp with a dp (m2) and racing beat cat back. the afrs were in the low 11's.



mike
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Old 10-29-2002, 05:32 PM
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266 sounds a bit low. I was on my way to 300 rwhp with similar mods. Only difference is I have a FMIC and stock cat. A/F's were below 10.
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Old 10-29-2002, 09:28 PM
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If you want to really find out the problem, then get another compression check, dyno the car with a wideband and tune appropriately. Get the compression checked again, though.
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