DC Sports 4-1 Header Installation onto xA/xB
01-07-2005, 12:07 AM
#1
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DC Sports 4-1 Header Installation onto xA/xB
In this tutorial, I'll be instructing on how to install the DC Sports 4-1 header (exhaust manifold) for the xA and xB. If you have a strut bar installed, you will need to take it out in order to get the stock header out and the new header in.
Tools needed:
Socket wrench
10mm, 12mm, 14mm Sockets
6" or 10" socket extension
Floor Jack
Jack Stands
Optional:
New Exhaust Manifold Gasket (P/N 17173-21020)
WD40 or PB'Laster (Godsend!)
12mm Deep Socket
Breaker Bar
Torque wrench
Work Mat/Blanket
First, you have the choice of reusing the exhaust manifold gasket or using a new one. I opted on using a new one. If you decide to use a new gasket, your installation may be delayed since it is usually not a part they have on hand at dealership parts departments. The part number for a new exhaust manifold gasket is 17173-21020.
Before uninstalling the stock header, make sure your engine is cool. You do not want to work on a hot engine. The bolts will expand when hot. To prevent from getting burned, let the engine cool down for an hour or two.
To ease the install, after an hour or so of cooling the engine, go ahead and take off the engine cover (10mm) to prevent any damage to it.
Unbolt the heatshield's 4 bolts using the 10mm socket and slowly take it out. The header's heatshield has sharp edges, so take caution.
Spray WD40 or PB'Laster on the header bolts/nuts, as well as the spring-loaded exhaust bolts. You should be able to get to the spring-loaded exhaust bolts from the top of the engine. Let the lubricant work into the threads for about 30 minutes. This will save some frustration during the uninstallation of the stock header.
After letting the engine cool down and applying lubricant to the bolts, it is time for the uninstallation of the stock header. Start by removing the 3 bolts and 2 nuts. Begin loosening the middle bolt, then work your way outward.
The two nuts on the header may need a 12mm deep socket depending on your sockets. I had no problems with a regular Craftsman 12mm socket.
Watch out with the 3 bolts. They are poor quality bolts. If you mess up one of these bolts (like I did), the replacement bolt (P/N 91641-K0822) is now (P/N 90105-A0047) and is a totally different bolt. The new bolt is shorter and tapered. It will not fit with aftermarket headers. The new bolts leave only 3-4 threads to hold the header to the head.
While you're working from above, go ahead and unbolt the 14mm bolt holding the header to the bracket.
Next, jack up the car via the designated front jack points. Always use jack stands when using a jack. Do not rely on a jack alone. On the second jack point, let the car rest on the jack stand, but have the jack in place for added safety.
With the socket wrench (and/or breaker bar), socket extension (6" or 10"), and 14mm socket in hand, go ahead and shimmy yourself under the car.
While watching out for the O2 sensor on the b-pipe, break the two spring-loaded exhaust bolts loose. They are very tight, so you may find yourself cursing the bolts to hell. You'll feel like a new person after taking them out, though.
While you're under the car, you can also unbolt the header bracket from the engine. I, personally, left it on.
Once the header is unbolted, do not try to take it out from under the car. Shimmy yourself out from under the car and slowly take the header out from the top.
xB owners may need to take their wiper assembly off to get the stock header out and the new header in. Though, I had no problems with my xA.
Here is a comparison of the headers (Thanks to George).
Once you're finished looking at the differences between the stock header and DC header, take the donut gasket off the collector of the stock header. Put the donut gasket on the DC header's collector. You may need to use a mallet, or another heavy blunt object (piece of wood), to get the donut gasket on the collector.
When installing the exhaust manifold gasket, be careful not to crease the gasket. Mount the gasket on the two studs on the engine and make sure it is on correctly.
With the header nuts in hand, slowly lower the new header into the engine bay. Once the header is mounted on the two studs, screw the nuts onto the studs to hold it in place. Screw the 3 header bolts back in and tighten them in this sequence.
Since I did not have a torque wrench, I tightened the bolts to the point where I thought, "Yeah, it's tight." I've talked to a few mechanics and they do the same. But if you would like to tighten them to spec, the header bolts/nuts are 20 ft. lbs.
Once the header bolts/nuts are tightened, grab your socket wrench with 14mm socket and the spring-loaded 14mm bolts, then shimmy yourself back under the car. Bolt the spring-loaded bolts back onto the b-pipe and header. The bolts will actually stop turning, so listen to the "Jack-in-the-Box" music until they stop. Again, tighten until "it's tight." The torque spec for the spring loaded bolts are 32 ft. lbs.
Shimmy yourself back out from under the car. Clean up anything that may be under the car, then jack the car up enough to get the jack stand out, then slowly lower the car back to the ground. Do the same for the other side of the car.
Recheck the bolts/nuts on the header and you're done! If you want to reset your ECU, check this tutorial out (click me). I, personally, did not reset my ECU, nor did I throw a CEL when I started my car.
Some people may wonder if their shifter linkage cables will melt since there is no heatshield to protect them from the header. With the ceramic coating on the DC header, it should not be any trouble. I’ve had my DC header on my car for a month or so and I have not had any problems. I can’t say the same for the other brand headers.
With the DC header coupled with a stock exhaust, I noticed improved throttle response. I could punch the gas to whatever RPM I desired much faster than with the stock header. I did not notice a significant loss in the low end RPMs, though I did notice an increase in the mid- and high-end RPMs. Also, I noticed no sound differences with the stock exhaust. Once I installed my new exhaust, the full potential of the DC Sports 4-1 header was evident.
If you have any questions, please post here, pm, or email me.
Tools needed:
Socket wrench
10mm, 12mm, 14mm Sockets
6" or 10" socket extension
Floor Jack
Jack Stands
Optional:
New Exhaust Manifold Gasket (P/N 17173-21020)
WD40 or PB'Laster (Godsend!)
12mm Deep Socket
Breaker Bar
Torque wrench
Work Mat/Blanket
First, you have the choice of reusing the exhaust manifold gasket or using a new one. I opted on using a new one. If you decide to use a new gasket, your installation may be delayed since it is usually not a part they have on hand at dealership parts departments. The part number for a new exhaust manifold gasket is 17173-21020.
Before uninstalling the stock header, make sure your engine is cool. You do not want to work on a hot engine. The bolts will expand when hot. To prevent from getting burned, let the engine cool down for an hour or two.
To ease the install, after an hour or so of cooling the engine, go ahead and take off the engine cover (10mm) to prevent any damage to it.
Unbolt the heatshield's 4 bolts using the 10mm socket and slowly take it out. The header's heatshield has sharp edges, so take caution.
Spray WD40 or PB'Laster on the header bolts/nuts, as well as the spring-loaded exhaust bolts. You should be able to get to the spring-loaded exhaust bolts from the top of the engine. Let the lubricant work into the threads for about 30 minutes. This will save some frustration during the uninstallation of the stock header.
After letting the engine cool down and applying lubricant to the bolts, it is time for the uninstallation of the stock header. Start by removing the 3 bolts and 2 nuts. Begin loosening the middle bolt, then work your way outward.
The two nuts on the header may need a 12mm deep socket depending on your sockets. I had no problems with a regular Craftsman 12mm socket.
Watch out with the 3 bolts. They are poor quality bolts. If you mess up one of these bolts (like I did), the replacement bolt (P/N 91641-K0822) is now (P/N 90105-A0047) and is a totally different bolt. The new bolt is shorter and tapered. It will not fit with aftermarket headers. The new bolts leave only 3-4 threads to hold the header to the head.
While you're working from above, go ahead and unbolt the 14mm bolt holding the header to the bracket.
Next, jack up the car via the designated front jack points. Always use jack stands when using a jack. Do not rely on a jack alone. On the second jack point, let the car rest on the jack stand, but have the jack in place for added safety.
With the socket wrench (and/or breaker bar), socket extension (6" or 10"), and 14mm socket in hand, go ahead and shimmy yourself under the car.
While watching out for the O2 sensor on the b-pipe, break the two spring-loaded exhaust bolts loose. They are very tight, so you may find yourself cursing the bolts to hell. You'll feel like a new person after taking them out, though.
While you're under the car, you can also unbolt the header bracket from the engine. I, personally, left it on.
Once the header is unbolted, do not try to take it out from under the car. Shimmy yourself out from under the car and slowly take the header out from the top.
xB owners may need to take their wiper assembly off to get the stock header out and the new header in. Though, I had no problems with my xA.
Here is a comparison of the headers (Thanks to George).
Once you're finished looking at the differences between the stock header and DC header, take the donut gasket off the collector of the stock header. Put the donut gasket on the DC header's collector. You may need to use a mallet, or another heavy blunt object (piece of wood), to get the donut gasket on the collector.
When installing the exhaust manifold gasket, be careful not to crease the gasket. Mount the gasket on the two studs on the engine and make sure it is on correctly.
With the header nuts in hand, slowly lower the new header into the engine bay. Once the header is mounted on the two studs, screw the nuts onto the studs to hold it in place. Screw the 3 header bolts back in and tighten them in this sequence.
Since I did not have a torque wrench, I tightened the bolts to the point where I thought, "Yeah, it's tight." I've talked to a few mechanics and they do the same. But if you would like to tighten them to spec, the header bolts/nuts are 20 ft. lbs.
Once the header bolts/nuts are tightened, grab your socket wrench with 14mm socket and the spring-loaded 14mm bolts, then shimmy yourself back under the car. Bolt the spring-loaded bolts back onto the b-pipe and header. The bolts will actually stop turning, so listen to the "Jack-in-the-Box" music until they stop. Again, tighten until "it's tight." The torque spec for the spring loaded bolts are 32 ft. lbs.
Shimmy yourself back out from under the car. Clean up anything that may be under the car, then jack the car up enough to get the jack stand out, then slowly lower the car back to the ground. Do the same for the other side of the car.
Recheck the bolts/nuts on the header and you're done! If you want to reset your ECU, check this tutorial out (click me). I, personally, did not reset my ECU, nor did I throw a CEL when I started my car.
Some people may wonder if their shifter linkage cables will melt since there is no heatshield to protect them from the header. With the ceramic coating on the DC header, it should not be any trouble. I’ve had my DC header on my car for a month or so and I have not had any problems. I can’t say the same for the other brand headers.
With the DC header coupled with a stock exhaust, I noticed improved throttle response. I could punch the gas to whatever RPM I desired much faster than with the stock header. I did not notice a significant loss in the low end RPMs, though I did notice an increase in the mid- and high-end RPMs. Also, I noticed no sound differences with the stock exhaust. Once I installed my new exhaust, the full potential of the DC Sports 4-1 header was evident.
If you have any questions, please post here, pm, or email me.
01-15-2005, 08:18 AM
#6
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Originally Posted by hornet_on_flower
did you use the new bolts you got???
Originally Posted by ProjectFusion
Did your header fit completely flush with the exhaust pipe connected with the spring loader screws? Everytime I go in reverse it sounds like there's a lot of air comin out from the header.
01-15-2005, 05:23 PM
#8
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Originally Posted by mikochu
Originally Posted by hornet_on_flower
did you use the new bolts you got???
Originally Posted by ProjectFusion
Did your header fit completely flush with the exhaust pipe connected with the spring loader screws? Everytime I go in reverse it sounds like there's a lot of air comin out from the header.
03-12-2005, 08:31 PM
#10
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Join Date: Jul 2004
Posts: 13,963
this header is the best!!! it improved my highway crusing power alot
your right about the fasteners very cheap!!! luckly i didn't mess any up (i used a "6 point sockets" is a must) and i also never seez'ed (spelling error) the spring loaded bolts
those were a pain in the sack i had to heat 'em up with a little help of m.a.p. gas torch (kind of like this
) then they poped loose litteraly after i PB'laster 'em but i didn't PB'laster the nuts and bolts on the head
i did notice a little under hood growl sounds very nice i might add!!! :D
tried to torque down the hear bolts and the torque wrench wouldn't fit very well
well just one and that gave me a good feel for the rest of the fasteners on the head 
took me about 2.5 hours too do
your right about the fasteners very cheap!!! luckly i didn't mess any up (i used a "6 point sockets" is a must) and i also never seez'ed (spelling error) the spring loaded bolts
those were a pain in the sack i had to heat 'em up with a little help of m.a.p. gas torch (kind of like this
) then they poped loose litteraly after i PB'laster 'em but i didn't PB'laster the nuts and bolts on the headi did notice a little under hood growl sounds very nice i might add!!! :D
tried to torque down the hear bolts and the torque wrench wouldn't fit very well
well just one and that gave me a good feel for the rest of the fasteners on the head took me about 2.5 hours too do
04-19-2005, 10:08 AM
#15
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Originally Posted by hornet_on_flower
just as long its a grade 8 bolt i don't really know the metric ver. of a grade 8 bolt
luckily some extra bolts from my 87 supra were the smae length , strength and pitch as the stock bolts on tha scion.
04-23-2005, 11:28 PM
#16
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Join Date: Apr 2005
Posts: 4
In your excellent article on the header installation, I didn't understand this sentence... do you mean "loss" in the low end RPMs?
"I did not notice a significant lose in the low end RPMs, though I did notice an increase in the mid- and high-end RPMs."
Would anyone hazard a guess as to the torque/hp curves that result from putting in the cold intake, 4:1 headers and axle-back exhaust? I couldn't find any data on the manufacturers' sites.
"I did not notice a significant lose in the low end RPMs, though I did notice an increase in the mid- and high-end RPMs."
Would anyone hazard a guess as to the torque/hp curves that result from putting in the cold intake, 4:1 headers and axle-back exhaust? I couldn't find any data on the manufacturers' sites.
04-24-2005, 01:03 AM
#17
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Originally Posted by NicholasBedworth
In your excellent article on the header installation, I didn't understand this sentence... do you mean "loss" in the low end RPMs?
"I did not notice a significant lose in the low end RPMs, though I did notice an increase in the mid- and high-end RPMs."
Would anyone hazard a guess as to the torque/hp curves that result from putting in the cold intake, 4:1 headers and axle-back exhaust? I couldn't find any data on the manufacturers' sites.
"I did not notice a significant lose in the low end RPMs, though I did notice an increase in the mid- and high-end RPMs."
Would anyone hazard a guess as to the torque/hp curves that result from putting in the cold intake, 4:1 headers and axle-back exhaust? I couldn't find any data on the manufacturers' sites.