I was hoping to get at least 170 before tuning
heres the setup
jg 64 mm t/b
toda b's
jg cam gears
3 angle valve job
head milled 40 thousanths
some port work
mugen header
jdm type r exhaust
chipped ecu
b&m regulator set at 46psi
stock intake and manifold

some this seem a little low to all of you, could the intake side be hold me back or does it just need some tuning, but this was a smooth graph though. I compression checked the motor and it was 180 on all four cylinders. It just seems so low to me.

 

I think you are lacking the compression needed to make good power with those cams...

 

Have you done any tuning? Numbers are definitely low. with a .040 mill, your compression should be fine for those cams. Have you adjusted the sprockets to compensate for the head mill? I'm sure with some tuning, you should be able to squeeze 175 out of it.

 

I have heard that Toda B's like compression to be around 11.8-12.3:1... Maybe I am caclulating wrong, but according to my calculations even with a .040 mill he is no where near that.


Modified by Gabe_ at 2:28 PM 1/1/2004

 

Toda's live off high compression. You bump that comp. up and you will see some VERY nice gains.

 

get a skunk2 intake manifold and hondata. Your fuel pressure is probably too high. I was making 182/131 with b's on my stock compression jdm gsr(10.6:1), stock fuel pressure, stock injectors, with an itr tb/jdm itr header/skunk2 manifold and hondata

 

Compression is Key in this setup.

My GSR made 160 and 118 at 6k. Acted stupid after that and went very Lean. Add compression and your car will be a wonder.

Can get forged pistons or you can do it the stock way and get a p30 or CTR piston.

 

Rather than join the compresion bandwagon- Perhaps do a leak down test and see how that 3 angle valve job is sealing. A lot of shops cut these and don't lap the valves with lapping compound and you will end up with 30% leakage past the valves. just an idea.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blwnb16a &raquo;</TD></TR><TR><TD CLASS="quote">I was hoping to get at least 170 before tuning
heres the setup
jg 64 mm t/b
toda b's
jg cam gears
3 angle valve job
head milled 40 thousanths
some port work
mugen header
jdm type r exhaust
chipped ecu
b&m regulator set at 46psi
stock intake and manifold

some this seem a little low to all of you, could the intake side be hold me back or does it just need some tuning, but this was a smooth graph though. I compression checked the motor and it was 180 on all four cylinders. It just seems so low to me.</TD></TR></TABLE>

Those numbers are low. I laid down 156hp and 118tq on an basically stock B17 with bolt ons. I would hope your numbers would be much higher.

Also, what is a 3 angle valve job? I cut on the seat and two cuts on the valve? Never heard of that. Typically you have 3 cuts on the seat and one on the valve, making a stock valve job a "4 angle". Some people have 5 angle jobs done which involved putting a backcut on the valve for a total of two cuts on the valve, and three on the seat.

 

Everyone screams compression, but does anyone know mechanically what more compression does for a motor with larger cams?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Unsung EM1 &raquo;</TD></TR><TR><TD CLASS="quote">Everyone screams compression, but does anyone know mechanically what more compression does for a motor with larger cams?</TD></TR></TABLE>

I wrote a paper on this subject as a final for my engine recon class. Here is a clip from it that explains a little more about the effects of cams and compression:

Cylinder pressures are greatly dependent upon when the intake valve closes, as well as an engines compression ratio. Since the static compression ratio is not related to the valvetrain, we will analyze the effects of cam timing on dynamic compression. If a valve closes too late, then some of the intake charge is pushed out of the cylinder, effectively reducing the amount of pressure we have in our cylinder. If we close the valve earlier, we will start with more of a charge in the cylinder and effectively increase the pressure. The problem is that if you close it too early at high rpm, then you aren’t allowing enough time to completely fill the cylinder with the air/fuel mixture. On the other hand, if we close the valve too late, we will loose a lot of the air/fuel ratio charge and also be shorting ourselves of some more possible power. To complicate the matter, as RPM changes, port velocity also changes how valve timing effects performance. Too much lift and duration cause a lumpy idle and will also cause poor gas mileage due to low port velocities at lower RPM. Too little lift and duration will ‘choke’ the engine off at higher RPM.

So, to review. Larger cams offer more lift and duration. More lift and duration will change the dynamic compression ratio. To make up for the loss in compression, you increase the static compression of the engine.

 

Perfect description. My thoughts are, your numbers are still weak for the amount of static compression you have. You can reduce your loss in dynamic compression by adjusting out some overlap on your intake cam, so your charge velocity isn't slowed to the point where you are in effect pumping back out the air you are drawing in. Either way, this goes to show the importance of adjustable cam gears.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Unsung EM1 &raquo;</TD></TR><TR><TD CLASS="quote">Perfect description. My thoughts are, your numbers are still weak for the amount of static compression you have. You can reduce your loss in dynamic compression by adjusting out some overlap on your intake cam, so your charge velocity isn't slowed to the point where you are in effect pumping back out the air you are drawing in. Either way, this goes to show the importance of adjustable cam gears.</TD></TR></TABLE>Yeah. Did you degree the cams in? generally if you degree the Toda's in you dont really have to do much dyno tuning...

 

leakdown test turned out find
just degreed the cams +2 intake -1exhaust and still got beat my a car and a half
by my friends 97 gsr with jdm type r motor, his fat ***, and heavy five lug
anybody know the most popular cam gear settings for the b specs and I have
the timing set to compensate for the milled head which retards my timing. My amount of compression might not maximize the potential of the cams, but it should at least get to 175 wtf

 

i think those numbers are just about right you have some good mods and decent compression of about 10:8:1. what you are lacking is tunning you have no vafc or hondata installed on your car so there is your obvious problem. fully tune with vafc you see around 175whp and with hondata i say def around 180whp.

 

milling .030 you should start at +2 +2. My cam gears are set at exaust 0(which would be +2 for you) and intake at +5

 

maybe you should check clearences fisrt before you advance the intake cam 5 degrees with that much of a milled head. Something else has got to be going on here. What exactly were your leak down #'s. And what kind of a dyno were the runs on. Please list fuel pressure, ignition timing, and leak down results by cylinder in % leakage and amount of lbs you pressurized everything to during the test. Maybe the kind of dyno will explain the numebrs but it still seems way way to low for a healthy with your mods.

 

ok when the car was dyno'd the cam gears were set at zero and fuel pressure was set at 44, so the timing was retarded, i have lowered the fuel pressure to about 40/41, and set the gears to +2 +2 adjusted the distributor and it is now at 18 degrees. I will set the will get the leak down numbers. hopefully that will help

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blwnb16a &raquo;</TD></TR><TR><TD CLASS="quote">leakdown test turned out find
just degreed the cams +2 intake -1exhaust and still got beat my a car and a half
by my friends 97 gsr with jdm type r motor, his fat ***, and heavy five lug
anybody know the most popular cam gear settings for the b specs and I have
the timing set to compensate for the milled head which retards my timing. My amount of compression might not maximize the potential of the cams, but it should at least get to 175 wtf</TD></TR></TABLE>
jdm type r motor? does he have a type r tranny?
if so, maybe the better gearing and lsd had play in his victory

 

Where did you tune at? I noticed youre in Rodeo.

A buddy that comes to the weekly HT meet in UC has a Gsr with Skunk Stage 2 cams, Jdm 4-1, testpipe, 310 injectors, Greddy exhaust, K7N drop in filter and Hondata tuned by Lawrence at Dsr. After 19 runs of tuning, it made 179/125.

Non milled/ported head, stock gsr intake manifold, ps/ac still on the car. The graph is smooth, its incredible how strong this lightly modified gsr is.

 

i only baselined the car i did not tune it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blwnb16a &raquo;</TD></TR><TR><TD CLASS="quote">i only baselined the car i did not tune it</TD></TR></TABLE>

Tuning is everything! With hondata and the right tuner I'm betting you'll see at least 175/125.

 

Maybe i'm going for the simple approach, but were the numbers corrected at all? If you're at high altitude and there was muggy weather it can skew your dynos big time.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blwnb16a &raquo;</TD></TR><TR><TD CLASS="quote">leakdown test turned out find
just degreed the cams +2 intake -1exhaust and still got beat my a car and a half
by my friends 97 gsr with jdm type r motor, his fat ***, and heavy five lug
anybody know the most popular cam gear settings for the b specs and I have
the timing set to compensate for the milled head which retards my timing. My amount of compression might not maximize the potential of the cams, but it should at least get to 175 wtf</TD></TR></TABLE>

dam my friends got a type r n when i had I/H/E on my Si i kept right on him, then in 3rd he walked a little.. now i got my CTR cams in, skunk valvesprings/retainers
type r valves, and aem cam gear set to 0 on both sides cuz i have no tuning, and i can slightly walk him. something is obviously out of whack here.

 

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

dam my friends got a type r n when i had I/H/E on my Si i kept right on him, then in 3rd he walked a little.. now i got my CTR cams in, skunk valvesprings/retainers
type r valves, and aem cam gear set to 0 on both sides cuz i have no tuning, and i can slightly walk him. something is obviously out of whack here.</TD></TR></TABLE>

sounds like your friends r is out of whack