My FE/Performance Project

[DRW]

Wow! Great project. My car has several similarities to yours:
I have 7.9:1 compression, pentroof combustion chamber, dished pistons, turbo, programmable ecu with lean burn. I've thought about rebuilding my engine with higher compression, but it's still running so I keep using it as is. I just wish my results were as good as yours.

Have you thought about using beehive valvesprings? They've just become popular in my corner of the tuner world. It seems they allow lower seat pressure, which reduces valvetrain friction, while still keeping the valves from floating or bouncing at high rpm due to the harmonic damping abilities of the variable diameter.

[DRW]

Oh yeah,
Oil squirters keep pistons cooler so you can run tighter piston clearance. Does your engine alredy have them?
Is there any way you could swap in a taller 5th gear from another drivetrain?
Have you considered using a custom cam with late intake closing to produce a Miller/Atkinson cycle effect?

[pgfpro]

Originally Posted by DRW

Wow! Great project. My car has several similarities to yours:
I have 7.9:1 compression, pentroof combustion chamber, dished pistons, turbo, programmable ecu with lean burn. I've thought about rebuilding my engine with higher compression, but it's still running so I keep using it as is. I just wish my results were as good as yours.

Have you thought about using beehive valvesprings? They've just become popular in my corner of the tuner world. It seems they allow lower seat pressure, which reduces valvetrain friction, while still keeping the valves from floating or bouncing at high rpm due to the harmonic damping abilities of the variable diameter.

Cool another turbo lean burn mobile. What A/F do you run in lean burn mode?

I had beehive springs on my Turbo 93 Talon AWD. They do work great!!!

Compared to my Talon the Honda spring seat pressure is lower then the Talon's so I stayed with the ZEX springs.

[pgfpro]

Originally Posted by DRW

Oh yeah,
Oil squirters keep pistons cooler so you can run tighter piston clearance. Does your engine alredy have them?
Is there any way you could swap in a taller 5th gear from another drivetrain?
Have you considered using a custom cam with late intake closing to produce a Miller/Atkinson cycle effect?

Unfortunately my Honda doesn't have oil squirters. I'm going to tighten up the clearances next year with the new engine.

I do need a taller 5th gear so i'm going to be swapping in a VX 5th gear.

I'm looking at having a custom cam ground to take advantage of the Miller/Atkinson effect. When I do this I will probably have to increase the compression though?

[imzjustplayin]

Originally Posted by pgfpro

I do need a taller 5th gear so i'm going to be swapping in a VX 5th gear.

I'm looking at having a custom cam ground to take advantage of the Miller/Atkinson effect. When I do this I will probably have to increase the compression though?

Doesn't work that way, you have to swap in the final drive as the gear ratio of gears 1-5 are the same on the DX/LX/VX/CX, the only difference being the final drive.

[DRW]

Originally Posted by pgfpro

Cool another turbo lean burn mobile. What A/F do you run in lean burn mode?

I had beehive springs on my Turbo 93 Talon AWD. They do work great!!!

Compared to my Talon the Honda spring seat pressure is lower then the Talon's so I stayed with the ZEX springs.

I'm not exactly sure of my AF ratio since my wideband only reads up to 18:1
When the car is in lean burn mode the AF ratio varies with load. At medium loads it's around 17.3 to 17.8.

[pgfpro]

Originally Posted by *************

Doesn't work that way, you have to swap in the final drive as the gear ratio of gears 1-5 are the same on the DX/LX/VX/CX, the only difference being the final drive.

My transmission has a .750 5th gear(P20/B000 92-95 Civic Si / 93-95 del Sol Si D16Z6) I'm going to a .702 5th gear(P20/B00 92-95 Civic EX D16Z6.)
They share the same
1st gear 3.25
2nd gear 1.90
3rd gear 1.25
4th gear.909
final gear 4.250 ratios the only difference is the 5th gear .702/.750.

I know its not to much of change but my plans are for only a 5 mph increase at the same rpm using the .702 with a taller tire.(so I can cruise at 65mph freeway speed)

I tried a VX tranny with my engine combination and it actually was a lot worse then with the Si trans.

Now if I had better aero mods I could use the VX transmission at a higher mph and it would probably work very well.

[pgfpro]

Originally Posted by DRW

I'm not exactly sure of my AF ratio since my wideband only reads up to 18:1
When the car is in lean burn mode the AF ratio varies with load. At medium loads it's around 17.3 to 17.8.

Thats awesome!!! Its cool to see another person doing their own lean burn turbo setup.

[imzjustplayin]

Originally Posted by pgfpro

My transmission has a .750 5th gear(P20/B000 92-95 Civic Si / 93-95 del Sol Si D16Z6) I'm going to a .702 5th gear(P20/B00 92-95 Civic EX D16Z6.)
They share the same
1st gear 3.25
2nd gear 1.90
3rd gear 1.25
4th gear.909
final gear 4.250 ratios the only difference is the 5th gear .702/.750.

I know its not to much of change but my plans are for only a 5 mph increase at the same rpm using the .702 with a taller tire.(so I can cruise at 65mph freeway speed)

I tried a VX tranny with my engine combination and it actually was a lot worse then with the Si trans.

Now if I had better aero mods I could use the VX transmission at a higher mph and it would probably work very well.

If a VX transmission is too tall, then try the final drive CX transmission from the '96-'00 Civic or the final drive from a M/T HX '96-'00 Civic. You're not going to notice an improvement from .75 to .702. If you're not aware, the HX and CX transmission from a '96-'00 Civic have a final drive of 3.722. This is taller and therefore better than the 4.056 of the DX/LX Civics but not nearly as tall as the 3.25 of the CX/VX Civics of 1992-1995. I'm considering that final drive ratio if I find that the CX/VX transmission that I plan to swap into my Civic is too tall to be driveable, a concern that you seem to have as well. Yes it'd be nice to bring that .75 down to .702 but I think it'd make more sense to change out the final drive as you still have a very short final drive what with that SI transmission and all.

[pgfpro]

Originally Posted by *************

If a VX transmission is too tall, then try the final drive CX transmission from the '96-'00 Civic or the final drive from a M/T HX '96-'00 Civic. You're not going to notice an improvement from .75 to .702. If you're not aware, the HX and CX transmission from a '96-'00 Civic have a final drive of 3.722. This is taller and therefore better than the 4.056 of the DX/LX Civics but not nearly as tall as the 3.25 of the CX/VX Civics of 1992-1995. I'm considering that final drive ratio if I find that the CX/VX transmission that I plan to swap into my Civic is too tall to be driveable, a concern that you seem to have as well. Yes it'd be nice to bring that .75 down to .702 but I think it'd make more sense to change out the final drive as you still have a very short final drive what with that SI transmission and all.

Something I didn't think about using a HX CX transmission from a '96-'00

Thanks for the info!!!