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I've been running the DC sports single piece 4-2-1 header for the EG civic and I'm using the Zdyne SECU for engine management. I have an AEM cold air intake for the CRX and I am using a straight pipe with an uncorked supertrapp the exits right behind the driver seat.  The attached dyno plot shows the tuned DC header vs the tuned Hytech header (sts legal version).  I'm not thrilled with the gains but it sure sounds cool.  The baseline run was made on Tuesday this week and the Hytech tune was made on Thursday with no other changes to the system so it's a pure, back to back comparison on the same dyno.

For your reference:

Yeah, $$$/hp ratio for the Hytech is pretty crummy. Anyone do a similar comparo with the ST legal version of the SMSP header? I'm betting you'd see similar gains, but I'm still curious.

Interesting seeing how the A6 compares to my Z6. The VTEC motor does have a nice advantage.

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Nate Whipple
NER
188/88 DSP ITR

So about 2 hp & 2 tq across the board for about $700 more.  Not exactly mind blowing, but a gain is a gain I guess.  I wonder if using a high flow cat would change the results any.

This varies from other gains I have heard with the HyTech. 

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Jason Frank
Bridgestone / datatoys.com / Redshift Motorsports STS Civic Si

TeamUndercoatRacing.com

Yeah, it sorta varies with what I've heard... but you know, hearing and seeing are two completely different things.  I've heard gains of 10whp... but the original tune was not optimal so not really an apples to apples thing. Shennifeild said I might see 3hp over the dc/greddy.  I guess he was about right.

Eh, whatever.

Hey Matt, what other stuff have you done to your motor? Rebuild? Fresh head? If you'd like, feel free to post up the other comparo. I'll fill in the blanks on my build in a follow up once the dyno sheet is posted.

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Nate Whipple
NER
188/88 DSP ITR

The motor has all the typical stuff.  I rebuilt the bottom end with new rings and bearings but I noticed that the pistons and bores were ovalized... Maybe that's costing me some power.  For example, if I rotated the pistons in the bores they would nearly bind at 90*.  :)  I had the head rebuilt by a shop which included some new valves and new valve springs for peace of mind.  I have a Zdyne SECU for engine management (which has pretty poor resolution).  My cat has 290k on it but appears clean.  The exhaust as tested is an uncorked supertrapp.  AEM CAI....  That's it.  As I understand it, my numbers are pretty low as I've seen other builds in the 120hp range.

 Here's a overlay I made using a couple pulls from Nathans D16Z6.  It's pretty interesting that the D16A6 is stronger until it runs out of breath.

 

Thanks man! The build on my motor is very similar. I put new rings/bearings in and had the head freshened up by Framingham Machine. Redshift chip in the ecu, UR crank pulley, DC 4-2-1 header, new OEM catalytic, Magnaflow resonator dumping in the tunnel, AEM CAI and P/S pulley.

Well worth that extra 100lbs I have to carry around!

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Nate Whipple
NER
188/88 DSP ITR

Howdy,

glagola1:

I've been running the DC sports single piece 4-2-1 header for the EG civic and I'm using the Zdyne SECU for engine management. I have an AEM cold air intake for the CRX and I am using a straight pipe with an uncorked supertrapp the exits right behind the driver seat.  The attached dyno plot shows the tuned DC header vs the tuned Hytech header (sts legal version).  I'm not thrilled with the gains but it sure sounds cool.  The baseline run was made on Tuesday this week and the Hytech tune was made on Thursday with no other changes to the system so it's a pure, back to back comparison on the same dyno.

Just an FYI, feel free to totally ignore it.

Back when I used to chase horsepower on a sportbike, we'd see torque/hp changes like that  between runs on the dyno.  Its good that it was the same dyno and no other changes were made to the car, but was it the same temperature?  Same motor & tranny temp?  Same humidity?  Same air density?  Had the dyno been used much in between?

I'm asking because it took us a while to learn that when you're in the 1% or 2% gain range, a whole _lot_ of things can affect the measurement.  Even when we made a run, made a change, and made another run we didn't have the full story unless we put it back to where it was and made another run to verify that something else we weren't accounting for hadn't changed.  And even _that_ didn't show the full story!  :-)

Mark 

marka:

I'm asking because it took us a while to learn that when you're in the 1% or 2% gain range, a whole _lot_ of things can affect the measurement.  Even when we made a run, made a change, and made another run we didn't have the full story unless we put it back to where it was and made another run to verify that something else we weren't accounting for hadn't changed.  And even _that_ didn't show the full story!  :-)

Mark 

In general, I'd have to agree with you.  Thanks to Steve Hudson's PowerCurve Dyno, I've spent a lot of time testing stuff this year on both the Miata and the Civic.  It took us a while to get a pattern down where we could do real back-to-back with good enough consistency to find 1-2 ft-lbs, which is especially critical when doing ECU tuning.  The Dyno Dynamics eddy current dyno is especially good at this, with a lot more resolution than the DynoJet (see upcoming GRM for more details on this).

As it stands, I got pretty much exactly the same dyno chart as Matt did and mine were only 30 minutes apart (installed the header with the car on the dyno). 

As for the comment on how a hi-flow cat would affect things, I also tested a gutted OE cat w/ the Hytech.  There was no difference until 5400 RPM.  Then a gradual increase up to a whopping 2 ft-lbs at the peak (3 whp total).  Woo-hoo!  Guess that new hi-flow cat allowance won't have much impact on STS after all.

--Andy

 

That isn't concrete data unless you dyno back to back, same day with the same air and engine temps.  On my NA Honda I can see up to 5-6hp differences from one pull to another back to back just with a slight change in coolant temp.  Granted...we are talking 350whp vs. 110whp so it isn't exactly apples and oranges.

 The DC has always been a great bargain header and makes great power.  I have run several SMS headers and never found a gain over my trusty old DC...in fact those damn SMS headers would rust and corrode in 2 months.  I got fed up with having to recoat a $1000+ header every 3 months, so I got a Hytech.  The workmanship is outstanding.  If you were running a more serious motor, I bet the Hytech would prove to make a few more hp.

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08 Lancer Evolution X - STU

DRAG:

That isn't concrete data unless you dyno back to back, same day with the same air and engine temps.  On my NA Honda I can see up to 5-6hp differences from one pull to another back to back just with a slight change in coolant temp.  Granted...we are talking 350whp vs. 110whp so it isn't exactly apples and oranges.

 The DC has always been a great bargain header and makes great power.  I have run several SMS headers and never found a gain over my trusty old DC...in fact those damn SMS headers would rust and corrode in 2 months.  I got fed up with having to recoat a $1000+ header every 3 months, so I got a Hytech.  The workmanship is outstanding.  If you were running a more serious motor, I bet the Hytech would prove to make a few more hp.

Did you read my post (directly above yours)?

I dynoed back-to-back and got the same relative results as Matt.  Virtually identical change across the board to what he saw, though my motor makes more power than his everywhere.  30 minutes between runs.  Little-to-no weather change.  Same warm-up procedure, etc.  We've gotten very good at doing repeatable stuff on this car at PowerCurve.  Enough to repeatably measure changes of 1-2 hp.

BTW, why did you suddenly bring this thread back from the dead? 

 
--Andy