Ok, i've been doing some thinking and some planning. On top of getting my **** handed to me(not badly) by a moderately built 5.0 on N20 the other weekend. I've come up with a plan for my car.

I'm wondering how much of a gain in power I will net from each the following changes.

1) 750cc injectors 9lbs -> 12lbs boost
2) Crower 62403's with the Spring/Retainer kit.
3) Porting out my existing LS head.
4) Swapping out my LS short block to a B20

Misc other stuff: ARP Head studs, 3Bar MAP sensor, bigger intank fuel pump. blockguard

What do you guys think? I'm running 9lbs right now, and on the verge of tapping out my 450cc injectors. The first order of business is to get some bigger injectors and dail the motor in @ 12lbs of boost. With my Zdyne standalone i'm running close to 75% duty cycle around 10lbs....

Then, on to the valvetrain components. If i'm happy with the way the car performs with the cams I may forego the B20 block swapout. I'd rather not have to pull the entire engine. I know N/A a good port job with the cams mention is 20~25HP, what does that equate to when FI is applied? Given that i'll have to dail out a bit of overlap due to the aggressiveness of the cams.

Onto the port job. I'm not really wanting to pull the head off again, as it just had a valve job 3000 miles ago. As of monday a compression test yeilded 185,180,180,180. Which is pretty good for a 110K mile motor B18A. I've heard that porting the exhuast on a boosted motor is more beneficial than the intake. But I may have to pull the head to install the valvetrain anyways......

Thoughts, suggestions, opinions?

Steven





[Modified by Speed PHreak, 7:00 PM 3/6/2002]

 

Gees, I know you people have opinions......

 

My opinion(no flames):

1. Buy 550 injectors
2. run 12psi boost on stock internalls
3. buy larger head gasket to lower the CR
4. Dyno time and time tuning Zdyne
5. (if you can take off head) port both intake and exhaust. Polish also.
6. Larger cams(if you have the money)

That should be some serious power gains.

 

Hmm, intresting. My questions

1) Why the 550s? That not a really large increase over 450's and depending on how much I try to push the motor, they'll prolly be tapped out around 14~16 PSI. Suggestion worth merit though, i'm pretty sure the 86-87 RX7 Turbo II injectors will work and they're 550cc(peak and hold, 89-92 are Saturated)

2) 12 PSI.....hmm sounds about right, not pushing the internals to the edge, tuning won't have to be as critical

3) IMO larger head gaskets suck. Lower compresssion = less power off boost and makes drving it annoying. Besides LS motors have 9.2:1 compression already. If anything i'd like to raise compression a few points. Get me some better response and more power for the boost....

4)Dyno time is always good.....if there was a decent one nearby

5)P&P is planned

6)In the market for some crower 62403's

 

my opinion:

-720cc
-12lbs
-tuning!

building internal engine components are always a good thing...

 

here's my opinion:
get 720s
run boost up to 15-16psi
conservative timing and fuel i.e. https://honda-tech.com/zerothread?id=138345
either P&P or go ls/vtec...

p&p and cams are pricey and a lot of work; it all depends on how much down-time you're willing to deal with

-Xerxes

 

So the consensus is 72 lb/hr injectors then. 14 lbs of boost would be evil....tuning

I'm gonna attempt to P&P job myself. Fist I'll just clean up the ports, remove casting marks, trash, etc....Then i'll gasy match the ports and maybe smooth out the short and far side radii....http://www.sa-motorsports.com has one hlluva DYI FAQ on port and polishing..The down time isn't really that big on an issue since this is my weekend car.....

 

As far as the PnP job, you WILL lose some low end, but it will be more than worth it on the top end with the LS head.

Try to avoid completely hogging out the exhaust ports and do one port at a time and mirror the job from the first one. Work the seperator thouroughly and knife edge it on the exhaust ports. You want the two sections of the port to combine as early as possible.

On the intake port, just do a smooth and polish, don't port much on the intake at all unless you plan to have a match ported intake manifold (Trust me on this...). You need to allow the 2 channels of the port to split as early as possible.

Avoid any chamberwork at all costs since this is your first time (unless it was already done during the valve job)... and most of all... TAKE YOUR TIME, don't rush this.. porting is slow and tedious and it is an ART, so don't push it too hard!

If you get the port right you will gain as much as 25-30Hp from just the port/polish on a turbo motor at the boost you are running now... ok maybe at 10psi or so.

Good Luck on the project.

 

Thanx for the tips X2BOARD, that the kinda stuff i'm looking for. I'll prolly be down for a week or 2 while doing this just because of work and other s*** so i'm note even gonna worry about rushing it.....just need a valve spring compressor.