Kooks headers installed and dyno'd

[ILLSMOQ]

Kooks headers installed and dyno\'d

I called Kooks a little while ago to see if they had a set of headers for the Viper. I heard they might be making them and I knew they had a big following with the LS1/Mustang crowd. Anyway, I talked to George R. and sure enough they just finished developing headers for the SRT-10. So I ordered a set. Here is a link to their site Kooks Viper SRT-10 headers

Here is a pic of all the parts - 304 SS, 1 3/4" primaries, merge collector, v bands and flex pipes. this is the offroad version. I was suprised to see secondary o2 sensor bungs since this is an offroad version, but they will come in handy for wide band o2 sensors in the future. I also liked how the bungs are angled instead of straight in like the Belangers, that should make pinching and melting wires less of a problem.

Stock tubular manifold next to the new Kooks header

The collector

From 3500 all the way up there is a good 25 to 30 wheel horsepower gain from the headers alone. Same thing with the torque. Climate conditions were very similar on both dyno runs.

The sound has also changed for the better. Overall it sounds bigger/deeper. It's a bit more mellow at idle and cruising. It's a little louder than it was at WOT but it's not as earsplitting as it used to be and it sounds real good.

The install was pretty tough since these are one piece headers unlike the Belangers that are 3 piece. The engine has to be moved over a few inches each way to get the headers in and almost everything else in the engine compartment had to come out or be moved....I'm thinking the supercharger will be easier.

 

[1DumpedViper]

Re: Kooks headers installed and dyno\'d

WOW! Thats cheap. Great gains for the money. Kooks has a huge Corvette following. Looks like I'll be ordering a set!

 

[MikeR]

Re: Kooks headers installed and dyno\'d

Im starting to lean towards the Kook's now too. I was with Kurtis today when he dyno'd. Nice gains to the wheels from a few weeks ago,when we had last dyno'd. He picked up 25rwhp with headers. It also sounds more GTS like now. He always rips by my shop and today it sounded soooo good. Kinda like a Viper should sound like.

 

[1DumpedViper]

Re: Kooks headers installed and dyno\'d

I'm confused by the stuff on their site. Do you also need the mid pipes? They are an extra $900. I'm running no cats now. Just trying to figure out the total cost!

 

[ILLSMOQ]

Re: Kooks headers installed and dyno\'d

Yeah, it's $2650.00 for what I bought so not exactly cheap. You could just buy the headers and have the mid pipes made up if you have access to a "good" exhaust shop.

While the install was difficult, the parts did go together perfectly. No clearance issues with any of the other parts of the car. The factory heat shields even fit well with a little reshapeing.

 

[1DumpedViper]

Re: Kooks headers installed and dyno\'d

Dam, I almost wet myself when I thought they were $1600. $2650 is still not bad seeing how the b&bs are 1k more. Nice numbers

 

[ILLSMOQ]

Re: Kooks headers installed and dyno\'d

Your right, the comparable B&B's are a grand more.

Oh yeah, some other info worth mentioning. Kooks told me they would have the headers to me by the 7th. For some reason they ran behind schedule and didn't have them done untill the 6th so they overnighted the headers to me at no extra cost(they are in NY and I'm in CA so it wasn't cheap). I had them when promised. It's nice to deal with a company that goes above and beyond to stay true to thier word.

 

[viperbilliam]

Re: Kooks headers installed and dyno\'d

I'm thinking of getting these but with the catted kit that allows hookup to the stock muffler system. How were the instructions? Feel any bottom end loss due to larger diameter pipes? How are the heat issues - better, same, or worse? Any others besides ILLSMOQ try these?

 

[ILLSMOQ]

Re: Kooks headers installed and dyno\'d

I'm thinking of getting these but with the catted kit that allows hookup to the stock muffler system. How were the instructions? Feel any bottom end loss due to larger diameter pipes? How are the heat issues - better, same, or worse? Any others besides ILLSMOQ try these?

There were no instructions...just the items I showed in the picture above, along with a t-shirt and some stickers. You need to buy the gaskets...go with OEM metal gaskets($20.00 each). The install is pretty straight forward. The toughest part is getting the new headers in along side the engine....the motor has to be lifted and moved over for each side. I also had to move the overflow reservoir, the heater/ac plastic box, the fuse box and the brake booster.

No bottom end(torque)loss. Infact the dyno graph shows a gain from where the run starts all the way up and I feel it.

I did away with all the heat issues before I put the headers in(no cats+corsa track). I used the factory heat sheilds and tightend up some of the wires and hoses routed near the exhuast. I thought about getting the headers ceramic coated before I installed them, but I couldn't wait...that would help even more. Anyway, no heat issues for me, with cats and a more restrictive exhaust you may have some sort of issue...you may not.

I wonder what the Kooks exhaust system sounds like. I added mufflers to my track system, it's quiet at idle but when I open it up it's still loud...and I think I'm killing my ears.

I don't know of any other car with these headers other than the car Kooks used to develop them.

The car is faster and sounds better. Very nice. get'em

 

[Viper X]

Re: Kooks headers installed and dyno\'d

The stepped headers - aka "GTSR" style which go from 1 5/8 to 1 3/4 like the B & B's have always made more power throughout the power band than the non-stepped headers.

When buying headers, like anything else, you get what you pay for.

 

[ILLSMOQ]

Re: Kooks headers installed and dyno\'d

X, did you ever dyno your car with the Corsa Track or something similar before you switched to the B&B catback? Also, do you have any sound clips of it with the B&B, I've always liked their stuff had it on a few other cars.

 

[Viper X]

Re: Kooks headers installed and dyno\'d

Yes.

It's been a while since my SRT-10 was N/A.

From memory;

The B&B's alone made over 35 rwhp and rwtq (they advertise 33 rwhp). Very good power over the entire band.

The Corsa track added another 15 rwhp over the OE crossovers / mufflers, with the headers already installed. It was very loud, though.

OE Cat delete, add Random Techs added another 10. Ear piercing.

The Cooks with Corsa's do make good power at the top of the rpm band, but don't do as well over the entire band as the B & B's.

Headers really aren't that good of a "bang for the buck" in our cars. The stock "headers" are really pretty good. I'd guess that you could get pretty good hp / tq gains by just going to RT cats, an open side exhaust and a re-tune, as your dyno sheet shows.

I'm working with a local exhaust guy on getting some more hp / tq while keeping noise to a reasonable level with a new muffler technology. We'll be trying his mufflers on my Paxton car. It has the B&B stepped headers and RT high flow cats with a full 3-inch crossover on it now. If we can get this car quiet enough (533 ci, Stryker heads, etc.) by going out the side (deleting the cross overs) it should work on most Vipers.

I'll let you guys know how this works out as I'll likely do the same treatment on my new coupe. I'll delete the OE cats and install RT high flows, his muffler and go out the side (deleting the cross overs).

Dan

 

[BLWNGTS]

Re: Kooks headers installed and dyno\'d

Take a look at Illsmoq's Dyno and superimpose it over yours Viper X. Stepped headers ARE better for the middle with NA cars... but who keeps that for long!?!?! Not only that but what.. you gain maybe 3+/- in the middle that you lose up high?!?! Look at the graph... he has a CONSTANT increase throughout the whole band!!
Any kind of Forced or heads and cam or nitrous system will benefit more with the straight through!! plus... it goes back to the same tired conversation AGAIN... WHERE DO YOU SHIFT!?!?!

With these big motors, straight is the way to go. If we were talking bout a little 4 ****** or 6, stepped is the best since you will NEVER put enough air through it and will lose torque.

 

[Camfab]

Re: Kooks headers installed and dyno\'d

Take a look at Illsmoq's Dyno and superimpose it over yours Viper X. Stepped headers ARE better for the middle with NA cars... but who keeps that for long!?!?! Not only that but what.. you gain maybe 3+/- in the middle that you lose up high?!?! Look at the graph... he has a CONSTANT increase throughout the whole band!!
Any kind of Forced or heads and cam or nitrous system will benefit more with the straight through!! plus... it goes back to the same tired conversation AGAIN... WHERE DO YOU SHIFT!?!?!

With these big motors, straight is the way to go. If we were talking bout a little 4 ****** or 6, stepped is the best since you will NEVER put enough air through it and will lose torque.

I don't get it. What are you trying to say? Yes they are better for N/A, but no they aren't if you have heads and cam which by the way is N/A. You shouldn't buy them because everyone goes to blown? They make more power across the curve, 25 HP and 25FT/TQ is nothing to sneeze at. Straight tubes on a N/A car tend to shift the torque curve more so than stepped, yes if your supercharged or are only interested in that peak # then a header specifically designed for your application may yield a small increase in peak power. The needs of every engine combination are different, just throwing on random sets of headers on one specific engine combo may give false theories about others. In general, and as shown in the above example a properly designed set of stepped headers will produce better power across the curve, which wins 99% of all races. The only arena where peak #'s are most important is in a pure drag car, 5000+ stall converter, geared for a very short power band.

 

[britospeed]

Re: Kooks headers installed and dyno\'d

I would'nt trust the second O2 **** for you wideband. The sensor will not get a good reading in that position.

 

[MikeR]

Re: Kooks headers installed and dyno\'d

Take a look at Illsmoq's Dyno and superimpose it over yours Viper X. Stepped headers ARE better for the middle with NA cars... but who keeps that for long!?!?! Not only that but what.. you gain maybe 3+/- in the middle that you lose up high?!?! Look at the graph... he has a CONSTANT increase throughout the whole band!!
Any kind of Forced or heads and cam or nitrous system will benefit more with the straight through!! plus... it goes back to the same tired conversation AGAIN... WHERE DO YOU SHIFT!?!?!

With these big motors, straight is the way to go. If we were talking bout a little 4 ****** or 6, stepped is the best since you will NEVER put enough air through it and will lose torque.

I don't get it. What are you trying to say? Yes they are better for N/A, but no they aren't if you have heads and cam which by the way is N/A. You shouldn't buy them because everyone goes to blown? They make more power across the curve, 25 HP and 25FT/TQ is nothing to sneeze at. Straight tubes on a N/A car tend to shift the torque curve more so than stepped, yes if your supercharged or are only interested in that peak # then a header specifically designed for your application may yield a small increase in peak power. The needs of every engine combination are different, just throwing on random sets of headers on one specific engine combo may give false theories about others. In general, and as shown in the above example a properly designed set of stepped headers will produce better power across the curve, which wins 99% of all races. The only arena where peak #'s are most important is in a pure drag car, 5000+ stall converter, geared for a very short power band.

That may be true and to some 25hp isnt a huge gain. But for those not wanting to spend 10k on a blower or doing heads and cam, the Kooks headers do a nice job. There is 25hp to the wheels at peak power that he gained,plus the whole power band he gains over his previous set up of just exhaust work. He went from 471rwhp to 496. Nice gains. And thats a difference in winning races. I know, he pulls ******* me now as I only have exhaust,no headers yet.

So for those looking to just add exhaust and headers, like myself, this is a perfect combo.

 

[ILLSMOQ]

Re: Kooks headers installed and dyno\'d

I would'nt trust the second O2 **** for you wideband. The sensor will not get a good reading in that position.

A little too far back huh?

 

[britospeed]

Re: Kooks headers installed and dyno\'d

The position isn't too bad, it's the angle. From the pics I would guess that only 1/8-3/16" of the sensor will see the exhaust gas, and the part that does is at what ever angle the **** is at. For saftey with the wideband I'd install another **** so that the sensor is 90* to the exhaust gas flow, and has enough *********** into the tube for proper sampling. Just my .02.
Michael

 

[FE 065]

Re: Kooks headers installed and dyno\'d

A very pretty set of headers. On the O2 sensor part, make sure the sensor isn't mounted at the bottom of the tubing where exhaust system moisture will foul the O2 sensor. I couldn't tell from your pic. I'd assume Kook's didn't weld the **** down low.

Ed, over at Headers by Ed doesn't think much about stepped headers btw.


Not to rain on your hard efforts, but since we're talking exhaust theory, on both a G1 and G2 Viper I've gained 20-25hp on cars that were already running aftermarket mufflers and no cats, just by adding this balance pipe that I made.

You must be registered for see images

For about $150 worth of tubing.


First in 1996, then again this past October.


1996 - I'm running consistent 12.38s on my no-headers G1, go back in the pits, bolt up the balance pipe, and run a 12.16 & 12.12 on the next 2 runs.


2006 - I'm running ETs on my no-headers '99 G2 that average 12.14, go back 2 weeks later with the only change being I bolted the pipe up, and run 11.94 & 11.89. (11.92 average)

Both cars running BFG DRs and a shift lite btw. The variable was the balance pipe.


It bolts up to a flanged T connection that replaced the flex screen with 3 bolt header flanges. About what - a foot from the end of the OE exhaust manifold, Easy to install, or remove. It does reduce ground clearance though. Maybe oval tubing would suffice for those who don't have the ground clearance to give up.


I haven't tried it on a G3, but balance pipes have been around a long time-just about always yielding a HP gain. The tubing is 2.5"OD, and the length may/may not be a critcal part of the HP gain.


I only have this one, so if you're interested you'll have to fabricate your own.


<font color="red">** ** ** </font>

 

[Camfab]

Re: Kooks headers installed and dyno\'d

I like your balance tube idea, are you routing the exhaust tubing up in the trans tunnel after that, or are you not showing the finished exhaust? I would guess that it smooths out the exhaust note as well. I would tend to believe that the balance tube will show the greatest yield on a non optimized header or stock exhaust manifolds. Every little bit helps, I like your old school approach.

 

[BLWNGTS]

Re: Kooks headers installed and dyno\'d

I don't get it. What are you trying to say? Yes they are better for N/A, but no they aren't if you have heads and cam which by the way is N/A. You shouldn't buy them because everyone goes to blown? They make more power across the curve, 25 HP and 25FT/TQ is nothing to sneeze at. Straight tubes on a N/A car tend to shift the torque curve more so than stepped, yes if your supercharged or are only interested in that peak # then a header specifically designed for your application may yield a small increase in peak power. The needs of every engine combination are different, just throwing on random sets of headers on one specific engine combo may give false theories about others. In general, and as shown in the above example a properly designed set of stepped headers will produce better power across the curve, which wins 99% of all races. The only arena where peak #'s are most important is in a pure drag car, 5000+ stall converter, geared for a very short power band.

Ok... look.. More air in needs more air out... SIMPLE AS THAT!! I know heads and cam is considered n/a but im talking modified to stock!! Stepped headers do get a little fatter torque curve by maybe 5+/- in the middle, but WILL not respond as well to modifications.. ie heads and cam, supercharger, nitrous, computer tune, exhaust, intake, etc!! Why do you think guys are gaining 25 - 50 hp by just changing headers on a blown motor!?!?

also... every engine is different. One might gain 30 hp on their where another would only gain 24!! Is all depending on the differences in tune, motor, etc. I tune and race..... and have been for a long time. Do you get it now??

 

[FE 065]

Re: Kooks headers installed and dyno\'d

I like your balance tube idea, are you routing the exhaust tubing up in the trans tunnel after that, or are you not showing the finished exhaust? I would guess that it smooths out the exhaust note as well. I would tend to believe that the balance tube will show the greatest yield on a non optimized header or stock exhaust manifolds. Every little bit helps, I like your old school approach.

All you're not seeing is the flanged T section on each side that replaces the flex screen.

The balance tube forms a U as each side goes towards the rear a couple feet and meets in front of the trans skid plate. I didn't run it straight across to avoid any hard nerfs shoving the balance pipe into the oil pan (!)

You must be registered for see images

Traditionally balance tubes have worked on header equipped cars with full exhaust systems (not open headers) too.

I haven't seen any reports of Viper headers alone adding more than this pipe did..

 

[ILLSMOQ]

Re: Kooks headers installed and dyno\'d

The stepped headers - aka "GTSR" style which go from 1 5/8 to 1 3/4 like the B &amp; B's have always made more power throughout the power band than the non-stepped headers.

When buying headers, like anything else, you get what you pay for.

I'd be interested in seeing the numbers across the board, not peak hp/tq numbers when comparing the stepped vs non stepped. How much more power do you think your making over the nonstepped headers...and then is it worth the extra grand, when headers are already not a great bang for the buck? If the power difference is a significant amount then it may be worth it to some. What is the new muffler technology your playing with???? I'm seriously looking at going with a full cross over system unless maybe you come up with something better.

I would'nt trust the second O2 **** for you wideband. The sensor will not get a good reading in that position.

when it's wide band time, I'll take a closer look at it....your right though that **** will shroud the sensor a bit.

A very pretty set of headers. On the O2 sensor part, make sure the sensor isn't mounted at the bottom of the tubing where exhaust system moisture will foul the O2 sensor. I couldn't tell from your pic. I'd assume Kook's didn't weld the **** down low.

I think one could make that mistake and install them upside down..I've got them in right....there is no O2 sensor there for me anyway....good tip for others to look out for though.

 

[Camfab]

Re: Kooks headers installed and dyno\'d

I don't get it. What are you trying to say? Yes they are better for N/A, but no they aren't if you have heads and cam which by the way is N/A. You shouldn't buy them because everyone goes to blown? They make more power across the curve, 25 HP and 25FT/TQ is nothing to sneeze at. Straight tubes on a N/A car tend to shift the torque curve more so than stepped, yes if your supercharged or are only interested in that peak # then a header specifically designed for your application may yield a small increase in peak power. The needs of every engine combination are different, just throwing on random sets of headers on one specific engine combo may give false theories about others. In general, and as shown in the above example a properly designed set of stepped headers will produce better power across the curve, which wins 99% of all races. The only arena where peak #'s are most important is in a pure drag car, 5000+ stall converter, geared for a very short power band.

Ok... look.. More air in needs more air out... SIMPLE AS THAT!! I know heads and cam is considered n/a but im talking modified to stock!! Stepped headers do get a little fatter torque curve by maybe 5+/- in the middle, but WILL not respond as well to modifications.. ie heads and cam, supercharger, nitrous, computer tune, exhaust, intake, etc!! Why do you think guys are gaining 25 - 50 hp by just changing headers on a blown motor!?!?

also... every engine is different. One might gain 30 hp on their where another would only gain 24!! Is all depending on the differences in tune, motor, etc. I tune and race..... and have been for a long time. Do you get it now??

Yes,I understand that an engine is an air pump. Your oversimplifying your statement that more in, means more out. If it's that simple, why not just put 500 mm throttle bodies on your car with 4" primary tubes on the exhaust. Blown motors have pressures far above atmospheric which tend to force exhaust as well as fuel out during overlap. N/A cars do not enjoy this advantage, save a very narrow rpm range where proper engine component design can yield volumetric efficiencies greater than one. Stepped headers allow for high velocities out of the exhaust port, then at the correct length, additional exhaust expansion for better scavenging. I believe my point above already stated that each motor is different and requires different header spec's. That the simple generalization that straight tube primaries are better for all heavily modded motors is false information.

I think we're basically on the same page, when it comes to blown motors or nitrous. Now if we're talking cost/HP gained by going stepped/merged, sure your probably right. My statement here does not involve cost, it's about what works best. I think if you look at most road race / open wheel non turbo or supercharged cars, you will see this type of header. If your example was standard headers vs. Tri-Y, I would have to agree with you 100%.

 

[FE 065]

Re: Kooks headers installed and dyno\'d

You just have to wonder about all that elaborate theory when a simple balance pipe tied in with OE exhaust manifolds can yield the virtually the same gains as the best of the headers offered for the car.

In the end it's about letting the cylinder evacuate fast enough and hoping it draws some intake mix into the cylinder as it goes out. It's been said that the exhaust phase can have 5x the effect on cylinder filling than does the downward stroke of the piston.

On a side note, before I bolted up the balance pipe, I tried running it with the T connections open-like a dump or cutout. The ET was still in the high 12.30s. The gain came after I went back and bolted up the balance pipe.

Why wouldn't the T connection just opening to atmospheric give the same gain? No one seems to be able to answer. Maybe the balance pipe is at less than atmospheric by luck of the length/OD combination.

- On the G1 I first tested it on, the car already had sidepipes of course, with no cats, and 2.5"ID Dynomax mufflers. It's not like the exhaust system could be described as restrictive before I put the balance pipe on.


I may try cutting off most of the U and adding a large box to increase volume and see what happens...

 

[Viper X]

Re: Kooks headers installed and dyno\'d

BLWNGTS,

It's not that simple as air in / air out. CAMFAB is correct and stating what I would have stated if I'd not been away.

Stepped headers were used on the GTSR engines as I stated. When a factory team designs a race car, they do the research and play to win. Stepped headers are more expensive but work better on a N/A road race car, period. It follows that that they work better on street cars and drag cars too.

Winning races isn't just about peak hp claims or dyno sheets as you imply and the tq / hp gains aren't just + or minus 3 or 4 hp in the "middle".

Think a minute. How much time, even in your drag car, do you spend at peak rpm compared to other rpm? Now think about driving a road course, if you ever have. You just don't spend that much time at peak.

On another subject, my SRT-10 makes over 900 rwhp on pump gas with only 10 lbs of boost with B&amp;B STEPPED HEADERS. Do they work on blown engines, yes.

Would another header make more peak hp, maybe, but again, you just don't spend that much time at peak rpm / peak hp.

Nice to see any Viper owner make his car run better. There's a bunch of other cars out there that we need to be able to beat up on.

Dan