So comptech says that headers give a mx increase HP of 32 at the wheels...what about at the crank? thanks..

g


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'01 Silver TYPE-S (navi)

• Spoiler
• Comptech Springs
• 18"ADR Enigma & 225/40
• 35%tint all around
• Polarg M-6
• Xephyr CAI
• Comptech Headers
• Comptech Sways
• Denso Iridium Plugs

Click here for pics of my CL!

 

The gain at the wheels is really 24 HP -- look carefully at the Comptech graph
232 - 208 = 24, not 32 HP. Multiply the 24 x 1.25 (assume a loss of 20% in the drivetrain). The gain is 30HP at the crank.

(I'm sure this varies from engine to engine etc, and I'm talking about a CL-S)

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Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (50 lbs less than stock)
• Comptech headers & sways
• Silver AEM CAI
• 12 coats of Zaino magic
• Stainless Brake lines coming (Brembos?)
• V1 planned

[This message has been edited by EricL (edited 06-15-2001).]

 

Intresting...I'm looking at the comptech catolog right now:

32hp gain at the wheels on a CL-S"*

*Your gains may vary, depending of the state of tune of your car.

Then in the graph below, at 6800 rpms, gain is 27 hp.

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'01 Silver TYPE-S (navi)

• Spoiler
• Comptech Springs
• 18"ADR Enigma & 225/40
• 35%tint all around
• Polarg M-6
• Xephyr CAI
• Comptech Headers
• Comptech Sways
• Denso Iridium Plugs

Click here for pics of my CL!

 

I'm looking at the PDF file at link:

http://www.comptechusa.com/images/dyno/2000CLSplot.pdf

Look at the pre-header max @ 6200 RPM = 208HP

Then

Look at the post-header max @ 6400 RPM = 232HP

So, 232 MAX - 208 MAX...

The power peak has moved from 6200 to 6400 +


Comment:

I think the 32 HP gain falls right on the boundary of deceptive practices, or at least demonstrates cleaver language and marketing skills (just the stuff to ruin an evening)...

They do show that 32 HP MAX gain at 6600 RPM, with the stock down to 199 and the Comptech headers up to 231. Sorry, I just don't too many good magazines or shops represent power gains that way (just my opinion...)

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Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (50 lbs less than stock)
• Comptech headers & sways
• Silver AEM CAI
• 12 coats of Zaino magic
• Stainless Brake lines coming (Brembos?)
• V1 planned

[This message has been edited by EricL (edited 06-14-2001).]

 

...they never said that the max horse was 32 more than stock they said peak at one point there was a 32 hp gain over that same point stock ...and i think its better it came earlier than peak



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'01 3.2 CL typeS
H&R o.e.'s 1.0/1.0
AEM cold air w/bypass
---PIAA 19224----
satin silver metalic
Llumar platinum plus
tint 20% all around
kill list
ITR.'98gt,GTP,contour SVT
GS-R,87 GT,supra...and more to come
-----------------
'98 ACCORD V-6 sedan
16" coupe wheels
215/55/16 nitto's
20% smoke titanium
black chrome kit

 

Huh?



------------------
Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (50 lbs less than stock)
• Comptech headers & sways
• Silver AEM CAI
• 12 coats of Zaino magic
• Stainless Brake lines coming (Brembos?)
• V1 planned

 

If you don't get what I'm saying (TypeR) go to a page of Sports Compact Car. Regardless of how Comptech words their claims, the basic indication of MAX or PEAK gain is finding the highest previous output (MAX function) vs. the modified MAX value.

If everyone was providing the area under the curve (of their power gains), there would be something to compare from one vendor to another.

But to compare the "difference" at a high point where the stock system is dying, just seems so silly. And this brings up a lot of confusion among new members about how much gain there really is.

Can you say "deceptive" marketing?

I'm not saying there is intent, but there I've sure seen a lot of people that got confused over that "Peak" HP statement.

MAX(new_HP_readings) - MAX(previous_HP_readings) = MAX increase




------------------
Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (50 lbs less than stock)
• Comptech headers & sways
• Silver AEM CAI
• 12 coats of Zaino magic
• Stainless Brake lines coming (Brembos?)
• V1 planned

 

i dont understand the difficulty ???at a point in the dyno the comp headers neted a gain 32 hp more than that of stock...however that point came after peak horse power i was mistaken as to where and that may be the "HUH" you refered to?However the stock cl-S lost hp at a rate 32 greater than that of the comptech header installed version....and still you think 24 isnt incredible???tell someone headers gave you a 24 hp gain someone that knows a little about bolt on performance...they wont believe you...now let me ask you this when you drive do you only drive at max horspower?obviously not the point is you experience the whole curve and with the comps at one point you experience the curve 32 higher thats all



------------------
'01 3.2 CL typeS
H&R o.e.'s 1.0/1.0
AEM cold air w/bypass
---PIAA 19224----
satin silver metalic
Llumar platinum plus
tint 20% all around
kill list
ITR.'98gt,GTP,contour SVT
GS-R,87 GT,supra...and more to come
-----------------
'98 ACCORD V-6 sedan
16" coupe wheels
215/55/16 nitto's
20% smoke titanium
black chrome kit

 

Hey TypeR, I think something is falling out of your mouth...

 

Well, here we go again...

First, I own and like the headers, so you don't have to convince me. Part II, these headers were made for the Accord. I still bought them knowing this. Don't you find it more interesting that they make this much horsepower using such a simplistic design. The reason the gains are so great, is the very poor design of the stock iron exhaust manifold. It is not some tuning genius that makes the Comptech headers work so well, it is the fast that ACURA DID SUCH A BAD JOB on our CL-S pipes!!!! They have the outer cylinders in each bank making hard right turns (gases don't like to make hard right turns). The length of the center pipe doesn't match that of the outer cylinders -- so pulse timing sucks between adjacent cylinders. The lower A-pipe in the stock header looks like it is having a collision between to gas streams! The analogy -- it would be like having an exhaust restrictor in our cars that was 1/2" at the tail pipes, then give credit to an exhaust manufacturer for genius to remove the restrictors with a welding torch. (So much for the engineering genius stuff...)

When syncivic posted his dynos, they were only a bit higher than Mike's. And people were saying, "Why should we pay $4K-$5K for a few more ponies." I responded that it was the area under the curve.

So, if one wants to compare apples to apples and oranges to oranges, compare the total area between a pre-modded curve and the post-modded curve to find the total area (power) made across the power band. Without a CVT, this would be a better indicator of true power felt and gained (I for one, would have to figure the shift points from gear-to-gear, and compare one type of gain to another. In other words, one would want to compare the area in the range of the shift from a lower gear to the redline.

When someone justs says that they make 32 more peak power, it is very deceptive, if you look at the curves, all that is really happening is the torque is staying up longer than before -- so the Comptech header doesn't die like the stock header.

I will give you a counter example, by your and Comptech reasoning that this measure of Peak power is OK (a good thing to let the customer know), then how about this scenario.

I now make a header that has 50 more HP at just 6800-6850 RPM, but it looses 20 HP from 4000 - 6000 RPM. Now, by using Comptech's "rules", I can say, "I have a peak gain of 50 HP." Some newbie is going to think that this is the best header since apple pie (if they don't study the data).

What is really important is the area under the curve. If you really want a realistic value, go for that. Unfortunatly, there is no current convention in the "trades" for doing that. The big racing concerns and aftermarket parts makers WILL do that type of analysis and check the total power gained (in house), this is what lowers ETs. But, until the magazines change their way, the use of an arbitrary gain in HP, tells a person nothing. One more example, I make an air intake that gain 10 HP at 6000-6100 RPM, but it looses 12 HP from 6100-6200 RPM. With Comptech's "scheme", I can just say I make up to 10 more HP. (pretty sneeky)

This reminds me of the old Hi-Fi/Stereo BS, where every one was using Peak Power with 4 ohm loads. The would turn up the line voltage to 130 volts, and send some sawtooth waves into an amp and measure the peak-to-peak voltage, then compute the power based on that figure. If someone tried that now, they would be smoked...

So, if you really like that mode of advertising, then fine -- as I said they publish a table of their gains, and if anyone spends enough time, they can evaluate the gains accordingly. However, don't forget that time-and-time again, we've had people confused by that Peak vs Max statement of theirs.

What do you like better -- facts that enlighten or facts that tend to confuse?

There is a point, where this does become a semantic issue, and I do understand the meaning of a "delta" or "difference" at a given point. I also know how it can be abused and how it has confused.

Finally, please do look at a page from "Sport Compact Car" or "Import Tuner" and do let me know if you ever see them show the TQ and HP figures represented as Comptech does -- they simply find the MAX value of each curve and compare it. AS I said, the real way to understand the gain is to integrate the area between the two curves

Pax


------------------
Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (50 lbs less than stock)
• Comptech headers & sways
• Silver AEM CAI
• 12 coats of Zaino magic
• Stainless Brake lines coming (Brembos?)
• V1 planned

[This message has been edited by EricL (edited 06-15-2001).]

 

ericl, what would you say your gains were in o-60 and the 1/4. you can keep all the other numbers. is it worth the investment for these 2 trials?

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01 BLK/BLK CL-S, FACTORY SPOILER, K/N DROP IN V-1
dom 11/00
98 INFINITI I30T(auto)
99 MAXIMA SE(auto)
lazy shifter

 

Hehe 24 x 1.25 is 30hp.. you need to divide 24 by 0.75 to equal 32 hp (100%-25%= 75% or .75) if you wanna go backwards.. otherwise you multiply 24 by 1.33 to achieve 32 hp... 32 hp minus 25% (due to auto trans) is 24 hp.


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2001 Silver CL-S
DOM: 10/2000

 

I gained 20hp on the dyno

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2001 acura type s
(red with nav nav)
web page of car
hometown.aol.com/vittallo/index.html

 

"Polished stainless steel headers & downpipe
30hp maximum gain, increased power from 4000rpm
for years: 2001 CL Type S"
What's wrong with this quote? On THEIR dyno it does show a gain of 32 hp @ a certain r.p.m.! Anyone that beleives it is across the board better have their head examined.


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2001 Type S White/Ebony with Navi and spoiler, Comptech Headers, sways, Rustoleum mod and xephyr cai, V1 with remote

 

Well, I was doing that in my head and goofed -- yep, it is 30 = (24 + 24/4). (Quick math + late night = I'm bad!)

AND the 1.25 correction factor from front wheel to crank is right. You took my simple math error and compounded it and assumed something that I did NOT do!


The TL folks have been pushing the 20% loss, I originally used some of the dynos to say it was more like 23%.


If you use the Comptech dyno for stock with peak at 208, with factory figure of 260HP at crank, then 52 HP gets cooked-off somewhere...

And 260 * (260*.20) = 208.

Now if I multiply the 208 x 1.25 I get the "correction" value to get back to 260. (This time I have a math calc out, just to check -- ok)

208 * 1.25 = 260, so a front wheel hp value SHOULD be multiplied by 1.25 to return the value at the crank.

So, if take there front wheel MAX value of 232 (24HP gain) and multiply it...

232 * 1.25 = 290... Hmmm, wonder why people call and/or use 290 in their sigs...


BTW -- if you want to do the inverse ratio, use the 20% figure, not the 25% figure -- it is too much of a loss. So, in lieu of your 1 / 0.75 = 4/3 = 1.333

you need the correct inverse of:

1 / 0.80 = 5/4 = 1.250


So, I goofed and you goofed too


------------------
Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (50 lbs less than stock)
• Comptech headers & sways
• Silver AEM CAI
• 12 coats of Zaino magic
• Stainless Brake lines coming (Brembos?)
• V1 planned

[This message has been edited by EricL (edited 06-15-2001).]

 

Have NOT done the 1/4 mile, but you could ask Mike, he is the guy who is "Mr quarter mile". He did the headers 1st, then the CAI, then the Toyos, then the SSR Comps. He can tell you what was gained. I can comment that his best time was after the wheels and tires (check his sig -- about 14.3).

I got more push from the wheels than from the headers and AEM CAI. I bought them all, so why would I lie? I can only tell you that my old GTECH to 60 with 1/8 tank at about 40 degrees out was around 6.1 seconds.
The car did the same second averaged two ways (with wheels, headers, and CAI) with a 1/2 tank at 80 degrees and the time was 5.7 seconds. It doesn't sound like much -- huh?

However, the first trial was done in very cold weather with the gas tank near the bottom. The "new" result is done with summer temps and about 50lbs more gas weight.

So, if you are asking me if the "headers" are worth it (for me) -- YES! The gain from 5K to 7K was worth it for me. However, I did have the AEM CAI put on the car at same time, so I can't tell you how much came from the AEM.


Note1: I find the headers and AEM are the secret weapon above 5 grand, and the power doesn't roll off. It really helps in the above 60 MPH area in 2nd, and at the top of 3rd gear.

Note2: I wouldn't expect to pull more than a car length to 60 MPH (with headers only). The power is only getting to the ground for a small fraction of the total time. When you are under aerodynamic load in 3rd gear at 80-114 MPH, there is quite a difference in my car.

Finally, I hope that people don't think that I'm bashing the headers, I like them, and I am not going to give them up. When I saw pictures of the stock manifolds, I knew they sucked -- the air flow is terrible.



------------------
Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (50 lbs less than stock)
• Comptech headers & sways
• Silver AEM CAI
• 12 coats of Zaino magic
• Stainless Brake lines coming (Brembos?)
• V1 planned

 

Your comment says it all. THANK YOU




------------------
Silver 2001 CL-S with NAVI

• Mud guards
• Wheel locks
• Toyo T1S 235/45ZR17-97W* Proxies on 17x8" SSR Competition wheels (50 lbs less than stock)
• Comptech headers & sways
• Silver AEM CAI
• 12 coats of Zaino magic
• Stainless Brake lines coming (Brembos?)
• V1 planned