Good IM for b18b
12-29-2005, 06:12 PM
#1
Good IM for b18b
Hey guys, iv been looking into a new intake manifold and bigger TB. But what i have found with the Skunk2 is it appears that the powerband it performs in is a little to high for the stock redline in a b18b. Is this true? If not where is the powerband of the skunk2 intake manifold. If it is not what i should be looking at can you guys recoment another Intake manifold that will be a more appropriate powerband.
Keep in mind i have a Shortram intake, Dc 4-1 headers 2.25 in cat, and cat back. I also might look into some mild cams. But the motor is not a heavy build.
Keep in mind i have a Shortram intake, Dc 4-1 headers 2.25 in cat, and cat back. I also might look into some mild cams. But the motor is not a heavy build.
12-29-2005, 06:51 PM
#2
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Join Date: Aug 2003
Location: Whitby
Posts: 4,816
If you don't have any cams there's really no need for you to upgrade your intake manifold.
Others to look at N/A wise are blox and aebs, but again, with those manifolds it will move your powerband upwards out of your tranny gear range. The mildest manifold that you could possible get right now, is the itr manifold, but some machining is needed to make it fit the non-vtec head. Fuzzy can better explain what's needed as I don't know. The ITR manifold will also move your powerband range upwards, so at this time it would probably be better for you to hold out.
Once you get the cams then decide to grab a intake manifold.
Skunk2 manifold's powerband is around 6800-8000rpm. It's roughly the same for the aebs and blox as well.
Type-R is about 5800-7200.
Also the intake manifold opening determines the correct sizing you would need for the TB. For example, the Skunk2 manifold opening is 65mm, so you would buy a 65mm Tb or buy a jdm itr tb @ 62mm and get that bored out to 65mm.
Reason behind why the manifolds won't help you gain any power without cams. Stock ls gearing and powerband location.
94-01 LS/GS/RS/SE
1st Gear Ratio 3.230
2nd Gear Ratio 1.900
3rd Gear Ratio 1.269
4th Gear Ratio 0.966
5th Gear Ratio 0.714
Final Gear 4.266
Redline (RPM) 6800
1st -> 2nd : 6800rpm x (1.900/3.230) = 4000rpm
2nd -> 3rd : 6800rpm x (1.269/1.900) = 4500rpm
3rd -> 4th : 6800rpm x (0.966/1.269) = 5200rpm
4th -> 5th : 6800rpm x (0.714/0.966) = 5000rpm
So you would like to have your mods make more power from 4000rpm - 5200rpm. Your exhaust system is working within this range and helping you.
Sadly enough this is where most ppl stop modding there car performance wise because anything other than the bolt-ons you already have starts to get expensive.
Things that you should look into before the intake manifold...
-Cams and the required valvetrain to go with it
Better ways to get the power to the ground
-motor mounts
-better tires
-springs, shocks & alignment
-upgraded rear sway bar
make good use for the power that you already have on the car:
-itr tranny
-lightened flywheel
-tuning, tuning, tuning
Hope that helps
Others to look at N/A wise are blox and aebs, but again, with those manifolds it will move your powerband upwards out of your tranny gear range. The mildest manifold that you could possible get right now, is the itr manifold, but some machining is needed to make it fit the non-vtec head. Fuzzy can better explain what's needed as I don't know. The ITR manifold will also move your powerband range upwards, so at this time it would probably be better for you to hold out.
Once you get the cams then decide to grab a intake manifold.
Skunk2 manifold's powerband is around 6800-8000rpm. It's roughly the same for the aebs and blox as well.
Type-R is about 5800-7200.
Also the intake manifold opening determines the correct sizing you would need for the TB. For example, the Skunk2 manifold opening is 65mm, so you would buy a 65mm Tb or buy a jdm itr tb @ 62mm and get that bored out to 65mm.
Reason behind why the manifolds won't help you gain any power without cams. Stock ls gearing and powerband location.
94-01 LS/GS/RS/SE
1st Gear Ratio 3.230
2nd Gear Ratio 1.900
3rd Gear Ratio 1.269
4th Gear Ratio 0.966
5th Gear Ratio 0.714
Final Gear 4.266
Redline (RPM) 6800
1st -> 2nd : 6800rpm x (1.900/3.230) = 4000rpm
2nd -> 3rd : 6800rpm x (1.269/1.900) = 4500rpm
3rd -> 4th : 6800rpm x (0.966/1.269) = 5200rpm
4th -> 5th : 6800rpm x (0.714/0.966) = 5000rpm
So you would like to have your mods make more power from 4000rpm - 5200rpm. Your exhaust system is working within this range and helping you.
Sadly enough this is where most ppl stop modding there car performance wise because anything other than the bolt-ons you already have starts to get expensive.
Things that you should look into before the intake manifold...
-Cams and the required valvetrain to go with it
Better ways to get the power to the ground
-motor mounts
-better tires
-springs, shocks & alignment
-upgraded rear sway bar
make good use for the power that you already have on the car:
-itr tranny
-lightened flywheel
-tuning, tuning, tuning
Hope that helps
12-29-2005, 07:04 PM
#3
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Join Date: Mar 2003
Posts: 7,392
unless you add cams or port and polish the head, there isn't really that much need for a bigger intake manifold, you won't see gains for the money you put in. instead, use that money for some cams and ecu tuning, you'll get a better outcome for your money.
12-29-2005, 10:33 PM
#4
Thanks for the input guys. cams are something on my list but i wasnt 100% sure that i wanted to go that route. But now it is starting to look more clear to me to maybe go with the crower 403s, and match the valvetrain to bring my rpms higher allowing for the power i could benifit from with an IM to complete it. And of course tuning.