- Tue Aug 03, 2010 10:39 am
#2638276
This thread is about discussing options to increase the power output of your k20a2, retaining the JRSC and it's power delivery characteristics.
Cams
An obvious solution, though can be costly. The 'best' OEM cams to get are from an '06 spec Acura TSX so you'll need to browse US forums or US ebay to grab a pair. I've seen some go for as little as $120 - plus shipping. The major cost however is in fitting them. If you've got a few hundred to burn or can do it yourself then go for it. You can of course get specially ground cams from Brian Cower etc Toda A3 cams work very well still, although an N/A spec. Things to bear in mind though is if you go Toda A3 you may want to think about replacing the retainers and springs and while you're at it, the cam chain tensioner. That Toda route has now shot costs up to £2k fitted.
How much BHP is that worth? 10-15bhp, but better when supported with...
DC5/RSX Inlet
This on it's own, without changing anything else on your EP3 is only worth 3-5bhp @ 8psi, but works well when paired with a shiny new set of cams. However, the outlay to convert your EP3 Inlet to a DC5/RSX Inlet works out to be around $1,127.74 plus shipping (current prices) when you've purchased all the bits you need. You'll have better drive-ability at part throttle due to higher torque at lower revs also. The cylinders will have better etg's due to better flow and the supercharger whine will be quieter.
So with more aggressive cams and the DC5/RSX inlet you can bump up another 20bhp (circa). However, with the DC5/RSX Inlet you can...
Aftercooling
You'll need the above inlet because of the placement of the bottom access panel. A core can be attached and can be plumbed into a radiator with electronic water pump. Here is a link to Club RSX that has a little info on the subject - Click me
I've read that our cousins over the pond are running around 13psi usually with the aftercooler installed. So if 1psi is roughly 8-10bhp, you could expect gains around 45bhp. I personally wouldn't expect more than 30bhp. This setup will cost between $600-700 plus shipping.
If you're into ghetto modding like the guy in the link above then...
Water/Meth Cooling
So far then it seems like you have to spunk a grand to get anywhere with the JRSC without mapping. That is until now.
You can purchase pretty much all you need for around £250 and it's simple to fit. What are the benifits? More boost, easily up to 11psi, which could be a nice 25-30bhp increase. But "wait", I hear you say, running 11psi when you've run out of mix is going to kill my engine to death! - Well, yes, that it will, but, KPRO has a neat little trick...
In the parameters table of KManager, there is a few tabs for Nitrous - now forget it says Nitrous because all it's doing is telling the ECU that when armed and the engine meets x,y,z conditions then run THIS fuel/ignition/cam map instead of the regular/'off meth map'. You're Hondata tuner should be able to turn the cam angles back on the regular map so it only produces 'safe' boost, 8psi, when not using meth. There are a couple of solutions on how to do this. You can either have meth map on all the time and have a low level indicator in your tank that trips the ECU over to regular when your mix is low, or 'arm' it when you please.
Methanol is pretty cheap so the running costs aren't going to go sky high, take into consideration that methanol is a fuel so petrol will have to be leaned off a bit when running meth. Sounds good so far doesn't it. However, take heed on the next bit.
Due to space limitations pretty much the only way to spray your mix in is 6" away from the throttle body, rather than direct port injection. On turbo builds this isn't an issue because the turbine blades won't be met by meth/water. The word is that the mix can dull the sharp edges, however, this setup has been run over the pond for years and the users haven't experienced any degradation in power or internal damage.
Click here to know how to do it.
Nitrous
Well, I suppose this has to be in here - easy installation and mapping, slaps another c45bhp with a 50 shot to your engine but lasts as long as a ride on Alton Towers Oblivion, then you have to find somewhere to go fill up your bottle again.
Other considerations
If you're setup is now cooled and you wish to up the boost it's not always beneficial to go for the smallest supercharger pulley! This may cause belt slippage, which any manual tensioner owner will confess is the bain of your JRSC EP3's life! Instead you must consider a larger crank pulley. You can pull the stock item off a k24 engine, or you may want to think about an aftermarket lightweight k24 crank pulley.
On the subject of tensioners, as I've preached before, bin your manual tensioner and mod the OEM tensioner to fit.
Exhausts, well 70mm is best, 2.5" is fine and dandy. At the end of the day, you're the one driving it, you decide how much noise you can tolerate.
Induction, open cone is superior to sealed units on FI applications. I wouldn't class the ARC kit as a sealed unit.
Injectors, the RC injectors are cheap and you get what you pay for. They do the job but there are other brands which will deliver smoother operation with a better spray pattern. OEM injectors can be modified however I'd be inclined to just get off the shelf seimens injectors. Also, I'm of the old school thought that you shouldn't be going beyond 85% duty cycle on your injectors for long periods. If you're running 99% you risk running lean at some point. If you're finding yourself in the high 90's alot of the time, have a think about going for the correct size for your modified car. Read here for more info
On the subject of fueling, you will need to liaise with your tuner on whether your stock fuel pump can handle the new found power potential.
Throttle body, 70mm if you can, it's not 100% necessary but if I was changing the cams I'd certainly be matching my throttle body AND throttle body housing to 70mm. I should coco that's it's worth between 3-5bhp top end when at that stage of tune. Be aware this may change drive-ability as you'll need to feather the throttle when pulling off gently.
Polishing - I don't think it's been proved beyond doubt that polishing imperfections out of the cast finish will significantly improve airflow enough to warrant the time needed to do it. Maybe 0.00001bhp.
The Future
You may or may not have heard of a company in the US called Redshift - for years they've been developing an inlet manifold for the JRSC that can be intercooled. The latest news is that it will be ready for sale to the public in December 2010 - This means you'll be able to run 14psi (although you're engine will see a drop in boost by the time the air has gone through the intercooler and too the cylinders). Redshift plan to offer a complete bolt-on package, click for info
So there we go, the JRSC isn't limited to 285-300bhp like everyone in the UK assumes.
Cams
An obvious solution, though can be costly. The 'best' OEM cams to get are from an '06 spec Acura TSX so you'll need to browse US forums or US ebay to grab a pair. I've seen some go for as little as $120 - plus shipping. The major cost however is in fitting them. If you've got a few hundred to burn or can do it yourself then go for it. You can of course get specially ground cams from Brian Cower etc Toda A3 cams work very well still, although an N/A spec. Things to bear in mind though is if you go Toda A3 you may want to think about replacing the retainers and springs and while you're at it, the cam chain tensioner. That Toda route has now shot costs up to £2k fitted.
How much BHP is that worth? 10-15bhp, but better when supported with...
DC5/RSX Inlet
This on it's own, without changing anything else on your EP3 is only worth 3-5bhp @ 8psi, but works well when paired with a shiny new set of cams. However, the outlay to convert your EP3 Inlet to a DC5/RSX Inlet works out to be around $1,127.74 plus shipping (current prices) when you've purchased all the bits you need. You'll have better drive-ability at part throttle due to higher torque at lower revs also. The cylinders will have better etg's due to better flow and the supercharger whine will be quieter.
So with more aggressive cams and the DC5/RSX inlet you can bump up another 20bhp (circa). However, with the DC5/RSX Inlet you can...
Aftercooling
You'll need the above inlet because of the placement of the bottom access panel. A core can be attached and can be plumbed into a radiator with electronic water pump. Here is a link to Club RSX that has a little info on the subject - Click me
I've read that our cousins over the pond are running around 13psi usually with the aftercooler installed. So if 1psi is roughly 8-10bhp, you could expect gains around 45bhp. I personally wouldn't expect more than 30bhp. This setup will cost between $600-700 plus shipping.
If you're into ghetto modding like the guy in the link above then...
Water/Meth Cooling
So far then it seems like you have to spunk a grand to get anywhere with the JRSC without mapping. That is until now.
You can purchase pretty much all you need for around £250 and it's simple to fit. What are the benifits? More boost, easily up to 11psi, which could be a nice 25-30bhp increase. But "wait", I hear you say, running 11psi when you've run out of mix is going to kill my engine to death! - Well, yes, that it will, but, KPRO has a neat little trick...
In the parameters table of KManager, there is a few tabs for Nitrous - now forget it says Nitrous because all it's doing is telling the ECU that when armed and the engine meets x,y,z conditions then run THIS fuel/ignition/cam map instead of the regular/'off meth map'. You're Hondata tuner should be able to turn the cam angles back on the regular map so it only produces 'safe' boost, 8psi, when not using meth. There are a couple of solutions on how to do this. You can either have meth map on all the time and have a low level indicator in your tank that trips the ECU over to regular when your mix is low, or 'arm' it when you please.
Methanol is pretty cheap so the running costs aren't going to go sky high, take into consideration that methanol is a fuel so petrol will have to be leaned off a bit when running meth. Sounds good so far doesn't it. However, take heed on the next bit.
Due to space limitations pretty much the only way to spray your mix in is 6" away from the throttle body, rather than direct port injection. On turbo builds this isn't an issue because the turbine blades won't be met by meth/water. The word is that the mix can dull the sharp edges, however, this setup has been run over the pond for years and the users haven't experienced any degradation in power or internal damage.
Click here to know how to do it.
Nitrous
Well, I suppose this has to be in here - easy installation and mapping, slaps another c45bhp with a 50 shot to your engine but lasts as long as a ride on Alton Towers Oblivion, then you have to find somewhere to go fill up your bottle again.
Other considerations
If you're setup is now cooled and you wish to up the boost it's not always beneficial to go for the smallest supercharger pulley! This may cause belt slippage, which any manual tensioner owner will confess is the bain of your JRSC EP3's life! Instead you must consider a larger crank pulley. You can pull the stock item off a k24 engine, or you may want to think about an aftermarket lightweight k24 crank pulley.
On the subject of tensioners, as I've preached before, bin your manual tensioner and mod the OEM tensioner to fit.
Exhausts, well 70mm is best, 2.5" is fine and dandy. At the end of the day, you're the one driving it, you decide how much noise you can tolerate.
Induction, open cone is superior to sealed units on FI applications. I wouldn't class the ARC kit as a sealed unit.
Injectors, the RC injectors are cheap and you get what you pay for. They do the job but there are other brands which will deliver smoother operation with a better spray pattern. OEM injectors can be modified however I'd be inclined to just get off the shelf seimens injectors. Also, I'm of the old school thought that you shouldn't be going beyond 85% duty cycle on your injectors for long periods. If you're running 99% you risk running lean at some point. If you're finding yourself in the high 90's alot of the time, have a think about going for the correct size for your modified car. Read here for more info
On the subject of fueling, you will need to liaise with your tuner on whether your stock fuel pump can handle the new found power potential.
Throttle body, 70mm if you can, it's not 100% necessary but if I was changing the cams I'd certainly be matching my throttle body AND throttle body housing to 70mm. I should coco that's it's worth between 3-5bhp top end when at that stage of tune. Be aware this may change drive-ability as you'll need to feather the throttle when pulling off gently.
Polishing - I don't think it's been proved beyond doubt that polishing imperfections out of the cast finish will significantly improve airflow enough to warrant the time needed to do it. Maybe 0.00001bhp.
The Future
You may or may not have heard of a company in the US called Redshift - for years they've been developing an inlet manifold for the JRSC that can be intercooled. The latest news is that it will be ready for sale to the public in December 2010 - This means you'll be able to run 14psi (although you're engine will see a drop in boost by the time the air has gone through the intercooler and too the cylinders). Redshift plan to offer a complete bolt-on package, click for info
So there we go, the JRSC isn't limited to 285-300bhp like everyone in the UK assumes.
Last edited by Drucifer on Wed Aug 04, 2010 3:31 pm, edited 2 times in total.
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