I went to the Columbus HT meet today at Slowmotion Motorsports and had my car dynoed.
177 WHP 124 WHP
Set up:
JDM B16A1
CTR cams, springs
CTR pistons
Custom exhaust (high flow cat, edelbrock muffler 2 1/4 pipe)
DC header 4-2-1
Ported/Polished head
Maxbore TB
AEM hybrid intake
Hondata heat shield gasket
MSD coil
AEM fuel pressure reg
Base tune with FJO wideband

I am pretty happy with the results.
Just thought I would share some actual dyno numbers.
There are two sets of lines, dotted is stock and solid is modified chip.

 

I was there. This thing friggin rips! This car gets the vote for "Best vtec crack ever heard"

 

Thanks for the compliment. Which car was yours?

 

good ****

nice to see some good numbers from a b16...

 

nice cross over

 

The new silver Type S

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hughesl &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for the compliment. Which car was yours?</TD></TR></TABLE>

maybe an rsx guessing from his user name.

 

nice. I always wondered what would have happened if I threw some ctr cams into my setup.

 

You need to change your vtec xover

 

Not to be captain obvious but like everyone said bump your crossover up to 5500. should take that dip out of it.

 

Good catch on the <TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CobblepotDC5 &raquo;</TD></TR><TR><TD CLASS="quote">maybe an rsx guessing from his user name. </TD></TR></TABLE>
I missed that.

RSX did well in stock form. He dynoed it with the temp tags.

I actually wanted to try dropping the Vtec on one of the dyno pulls just to see the impact. I think I must have grabbed the wrong chip because it doesn't look like the change over dropped to 4200 as expected. I was also thinking about getting some adjustable cam gears. Of course to tune those would take more time on the dyno. What kind of gains could be expected by adjusting the cam timing?


Modified by hughesl at 1:16 PM 6/24/2007

 

The current change over is at 5200.
Looks like it started tapering off power at about 4800.
Wouldnt bumping the change over to 5500 make the dip even worse?

 

you lost 20hp at changeover. i would bump it up to 5500 or 5800. take it for a drive and see how it feels. if you don't like it put it back.

 

Alright. I don't want to argue just for fun. Your proposal challenges my fundamental understanding of this engine set up, so I want to discuss a little. If I am wrong then my knowledge base will further be improved through this debate.

The first chart is my estimate of what your proposal would do to the power curve.
From a butt dyno perspective it would probably feel like I had wicked gains as the vtec change over would feel very strong as the large lobes gained back the power lost by holding the small cams longer.


The second chart show my proposal of lowering the change over. Your butt dyno would tell you that you lost power as the change over would be very mild. In actuality the area under the curve would be improved and total power would be increased.


Any comments to add to this would be appreciated.

 

try it, you could only improve things, you have to be able to feel that dip. i'm still feeling that it should be higher, but yes either the low cam is falling on its face or the change over is killing it. i would also be interested to see what the timing looks like at the change over.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by abnaasefmb &raquo;</TD></TR><TR><TD CLASS="quote">try it, you could only improve things, you have to be able to feel that dip. i'm still feeling that it should be higher, but yes either the low cam is falling on its face or the change over is killing it. i would also be interested to see what the timing looks like at the change over.</TD></TR></TABLE>

To put it simply...your right, he's wrong.

The Vtec crossover point needs to be higher for a flat curve. This is due to the intake air velocity suddenly slowing down once the larger lobe comes into play. The RPM's have to be high enough to support the added flow of the larger lobe.

Try it out. you'll see I'm right. You can actually tune the VTEC crossover so that you won't even notice it. However, whats the fun it that?

 

bryson, i'm trying to be a nice guy here

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by abnaasefmb &raquo;</TD></TR><TR><TD CLASS="quote">bryson, i'm trying to be a nice guy here </TD></TR></TABLE>

abnaasefmb......(plays well with others)...lol

 

OP: Are you positive that the crossover is at 5200?? If it is, then I agree that lowering it would help, according to your dyno chart.

Are the rest of you guys assuming that he's wrong and that crossover is closer to 4800?

 

Keep in mind vtec engages with oil pressure. Setting it too low is not always the answer. The only way to find out is to get that thing on a dyno and mess with it

 

I could be wrong.
Stock OBD0 PR3 change over is what?
My understanding is that it is at 5200, but I have seen multiple published numbers.
If I go by the tach that looks about correct.
Of course the tach is stock so it could have error.
Anyone know?
I agree the best way to resolve this would be to just change it and dyno.
Unfortunately I am messing around with the stock program and I have not figured out the cell locations for the vtec yet so I can't just burn a new chip yet.
Maybe this will be my winter project. I know PGMFI.org can help me with this.
I have the spoon program that drops the Vtec to 4200, but nothing that raises it.
I also do not have opportunity to hit the dyno every day.
If anyone has experience (dyno charts would be great) that will help me plan for when I actually do get to the dyno again.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostwerks.com &raquo;</TD></TR><TR><TD CLASS="quote">

To put it simply...your right, he's wrong.

The Vtec crossover point needs to be higher for a flat curve. This is due to the intake air velocity suddenly slowing down once the larger lobe comes into play. The RPM's have to be high enough to support the added flow of the larger lobe.

Try it out. you'll see I'm right. You can actually tune the VTEC crossover so that you won't even notice it. However, whats the fun it that? </TD></TR></TABLE>

So true, your not supose to have vtec crack, i would mess with the x over and add some timing to get the curve back up

 

either way good #'s for a mild 1.6

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hughesl &raquo;</TD></TR><TR><TD CLASS="quote">I could be wrong.
Stock OBD0 PR3 change over is what?
My understanding is that it is at 5200, but I have seen multiple published numbers.
If I go by the tach that looks about correct.
Of course the tach is stock so it could have error.
Anyone know?
I agree the best way to resolve this would be to just change it and dyno.
Unfortunately I am messing around with the stock program and I have not figured out the cell locations for the vtec yet so I can't just burn a new chip yet.
Maybe this will be my winter project. I know PGMFI.org can help me with this.
I have the spoon program that drops the Vtec to 4200, but nothing that raises it.
I also do not have opportunity to hit the dyno every day.
If anyone has experience (dyno charts would be great) that will help me plan for when I actually do get to the dyno again.</TD></TR></TABLE>

I'll solve your problem...

your wrong. Haha.

But seriously. Your OBD0 PR3 has a crossover around 4800 (which is confirmed by your graph). The OBD1 ECU's that came into play in 92 have the crossover a little higher at 5200.

I would reccomend you set the crossover at 5500 if you want a flatter curve. However, like I said, you won't even notice the crossover with your butt dyno...you'll simply hear it. If you want to keep VTEC fun, I'd set it to 5200.

 

id almost say to put your vtec at around 5.6-5.8kit doesnt look like you gained very much from the "Base" tune. but listen to everyone else and raise your vtec engagement