Seeing a good discussion in the other post..I have a few question on my own dynochart.
(It is not a B18C5 engine...but this forum seems much more knowledable then the Integra forum no offense)

This is very vauge...but any idea how benificial rasing the redline would be? How high should I go? the torque band starts to drop at around 6200..does this mean the HP will soon follow as well?

 

You may want to raise the limit by a few hundred rpm so that when you shift are still high on the hp/trq curves...I prefer to have the redline just as the power begins to fall off. If I am wrong someone please correct me.
Austin

 

Hmm..only by a few hundred? I was thinking more along the lines of a 8000 RPM redline.

 

You could raise it to 8000 but would your valve train handle it?
Also, your engine if not modified will stop producing power for a few reasons.
1) air flow is already at its maximum level.
2) valve seat pressure gets less and less as RPM's go up(unless you have heaier springs as stated earlier.) This tends to leave less air in the cylinder to burn.
Ive done extensive testing wth my car at the strip and at solo's with shift points and rpm limits. Ive found that shifting just after the torque curve falls off, right before the HP numbers start to plataeu, will give you the best times and performance. ( that is if you dont misshift )

 

I have Crower dual valve springs as well as Crower TI retainers...
and will be upgrading the rods and buying a girdle before attempting to rev 1000+ over stock redline.

How can you tell/know that airflow is at its maxium level?

 

I'd add a touch of fuel ~5000rpm, that's not too lean, but play with the fuel onthe dyno and see what happens. The HP is already starting to even out on the high end of the graph, so I'd say 7500rpm. I have a feeling that power will be dropping off after that pretty quickly.. unless other things are changed.

 

do you have stock pistons in your b20 if so donot touch the rev limiter.
also i would richen the whole run so you are at about 13.1 air to fuel. this will help too life of your motor on the street especially in a b20 vtec. if you have cam gears try advancing to +2 on the intake with stock pistons dont want to go farther than that.

 

with that plot, I say you will make peak HP around 7200-7300. The HP is a function of torque, so as the torque falls the HP will follow.

I say a redline around 7500 or 8K will sufice.

 

Like I said on Club Si, a little bit will make a difference. 8,000 I would say. Those cams pull all the way up to there, and you do have the valvetrain to handle it!

No one says you have to redline it everytime you drive, but you will have the ability when you need it!


[Modified by TypeR0207, 9:10 AM 8/22/2001]

 

Thank you for the replies.

Mark P: You said if i have stock pistons dont go over the stock revlimit?
Why is that? usually the rods/rod bolts are the weak link..not the pistons...correct?
Or are you thinking the high piston speeds will create too much heat for the stock pistons?

(BTW this is not a B20 VTEC)

 

Lean it up at 2-3500 you'll pick up more torque for daily driving. Make sure your valve train is up to task before pulling the rev limit. Also those rods may not be strong enough for higher rpm usage. That's why you would want to go with something a little stronger.

 

After shifting - where would the ideal area for the next gear be in the powerband?
Around where the torque peaks?

 

have you tried moving your xover point higher? ideally you want to stay around the peak torque yes. I'm guessing when you shift at 7 you go back to around 5 right? looks like there is more power to be made there.

 

Hmm..how do I go about moving the x-over point on a non-VTEC engine?

 

whoops sorry thought you had vtec..so used to talking to guys with vtec's..

 

Heh...yea I get that alot...people look at the chart and automatically assume its a VTEC engine

So and thoughts on the "ideal" RPM to land at after an upshift?


[Modified by HX_Guy, 9:00 AM 8/22/2001]

 

The first thing I thought was...

"What rpm does that ls tranny drop you to when you shift at 7??" hehehe

I think the ideal point to drop to would be just above 5k rpms. That is where I have noticed better times from my b20.

Good luck,

Pete

 

Try adding more fuel to smooth out the flat portion of the curve at 5000-5500. What controller are you using? VAFC? DFI? Not sure if I missed it above, but what is your setup?

 

Well...good thing I just got a GSR tranny this past weekend

The LS tranny was a DOG!
1st to 2nd = 4117
2nd to 3rd = 4675
3rd to 4th = 5329
4th to 5th = 5174

Now with the GRS gears...
1st to 2nd = 4117
2nd to 3rd = 5010
3rd to 4th = 5322
4th to 5th = 5328

You can see that 2nd to 3rd shift is much better now then before...plus the 4.40 vs 4.26 FD revs much nicer.

If I raise my redline to 8000, the gearing with the GSR gears would look like...
1st to 2nd = 4706
2nd to 3rd = 5727
3rd to 4th = 6013
4th to 5th = 6089

Hmm..is that shifting past the "ideal" point?

 

The current setup for that dynochart was:

B20Z2
Crower 62404 cams
Crower Valve Springs
Crower TI Retainers
Skunk2 intake Manifold
DC 4-1 header
DC 3" diameter C.A.I.
Tanabe exhaust
B&M Fuel Regulator
Apex'i S-AFC
16 Degrees timing
Stock cam gears

I have since bought some adjustable cam gears and will be tuning them this Saturday.

 

the gears will pull even more HP.

 

What do you mean by "pull even more HP"? O nteh dyno itself..or what are you refering to?

 

???

 

Sorry to change the subject...but on your website it said in the middle of the swap: "Out with the old..in with the new! There's the B18B1 in the back!". I thought you had a B20 in your civic.