Boosted_Coupe

I posted this in the Engine Management & Tuning section already, but think I will get more viewing traffic here

Ok, I went to the dyno last night/this morning to get my car tuned.
Here are my specs on the engine..
2nd Gen B16 head
Supertech springs and retainers
ITR cams (But now I'm not so sure anymore)
Skunk2 Pro Series IM
Stock TB
Stock Ignition

B18C5 Bottom End - Just rebuilt 81.5mm
9:1 comp Eagle H Beams, Wiseco Pistons

Peakboost topmount kit
Garrett 60-1 Turbo
44mm Tial WG
2.5" Charge Piping
3" Exhaust, no cat, chambered 3" Magnaflow muffler
HBC manual boost controller

1200cc Injectors
255lph fuel pump

Neptune RTP software
94 Octane gas

I made about 360whp, 266tq on my setup last night. Thats around 7500ish rpm, where afterwards, the engine was falling on its face, losing power. Mechanical timing is dead on, ignition timing is dead on.
NGK #8 plugs, checked them twice during tuning, checked out fine.
Boost IS creeping, from 13-14psi to about 15-17psi
Everything checks out ok, didn't run into any noticeable problems...

Except the fact that on my B16 Block - 9:1 comp, Eagle H Beams, Wiseco Pistons, 81mm Bore - it made 370whp and 244tq - that was boost creeping to about 16psi, revved to 8500 and a 38mm wastegate, on CROME, with 780cc injectors, running over 80% duty, and a Magnaflow 3" steel cat.

The car makes good power though. I see more hp, especially tq sooner, and midrange, the engine definitely makes promising power, but it starts struggling at top end to make more.

Now, the cams are a long story, and I can't say for sure if they really are ITRs, but they're the same ones I ran in the B16 setup.

My tuner had to lean it out at top end to make more power. We even disconnected the muffler to have it straight through 3" to see if that was my problem, but it didn't make a big difference, where we could even say that the muffler is being way too restrictive for this setup. Obviously it DID make a bit more power without it, but nothing phenomenal.

We were thinking that the cams are the major drawback to this engine performing the way we expected it to, especially with a hollow cat, and controlling the boost would be much more beneficial to tuning more precisely.

SO....! Maybe we're thinking too much, or not hard enough, but if anyone has any suggestions, please feel free to toss them at me. I tried to supply all the information about my setup that is coming to me right now. If you have any questions about it, ask away.

Sorry for the long-*** post, I made an attempt to keep it as simple as possible, given the situation.

EARLdaSQUIRREL

the difference in numbers could be from the temperature and humidity differences, also the difference in power band could be from the stroke

Boosted_Coupe

The tempature was roughly the same. I guess what we would like to know, or figure out, is what's holding us back. We're thinking the cams..

JRSC01GS-R

were both motors dyno'd at the same shop? there is a lot of variation from shop to shop

forced00si

boost leaks

Boosted_Coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JRSC01GS-R &raquo;</TD></TR><TR><TD CLASS="quote">were both motors dyno'd at the same shop? there is a lot of variation from shop to shop</TD></TR></TABLE>

Yes both motors were done on a Dynapak, by the same tuner, at the same shop.

We did not have a boost leak what-so-ever.

Jonatptp

check the data on the dyno runs, it will give you the humidity, temperature, and correction factor. I would check there first.

SovXietday

What AR on that turbo? Could be the cams too I guess.

360 and 370 is pretty tough to guage between on a dyno, but the car struggling to make power at the top end is interesting.

base-op.1320

Even though your hp is lower your car will be faster with the more torque. I bet its just the difference in engine stroke, block height, rod length that is giving you more torque less hp than the b16. hp is just torque at a given rpm so if you make more torque earlier then your hp is probably falling of earlier for that reason.

Boosted_Coupe

These are the exact specs of my turbo.

flow: 61 lbs/min 781cfm

.70 A/R housing

60 TRIM wheel

TURBINE SPECS:T3

.63 A/R housing

HIGH FLOW 76 TRIM stg 3 wheel

oil lubricated centersection.

for use with external wastegate.

COMES STANDARD WITH 360 DEGREE THRUST BEARING!!!

supportable of 575whp!

ITR0529

You said thay your injectors are running over 80% duty cycle. I would change out injectors for biggers ones so you can run a lower duty cycle. If you continue to operate them at such a high DC, they are going to fail sooner then they should.

Just my 2 cents.

base-op.1320

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ITR0529 &raquo;</TD></TR><TR><TD CLASS="quote">You said thay your injectors are running over 80% duty cycle. I would change out injectors for biggers ones so you can run a lower duty cycle. If you continue to operate them at such a high DC, they are going to fail sooner then they should.

Just my 2 cents.

</TD></TR></TABLE>

That was on his old setup, he has since upgraded injectors.

Turbo-LS

iTrader: (4)

My bad i didnt read fully, still even over 80% on 780cc's for 360whp is to high IMO


Does anyone not see that fact that he is running over 80% duty cycle on 1200cc injectors on gasoline?????

You have a fuel delivery issue my friend. Stop boosting and correct it asap. You shouldnt be over 80% duty cycle on 1200cc injectors at mid 300whp range. You should be closer to 55-65% duty cycle or possibly less. Check all yoru fuel lines, relace your filter and check your regulator. also bench flow the injectors to test there working properly.

personally i would pull th eline off the rail and cycle the key on and see how much fuel pours out into a container. if your not getting enough fuel volume then your duty cycles will be high and cause the lack of power up top and lean/blow your engine. then just go from there testing where the blockage is.

How many miles on the chassis? Last time fuel filter was replaced? Did you get the walbro new or used etc..... More details on the fuel system please

Boosted_Coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbo-LS &raquo;</TD></TR><TR><TD CLASS="quote">
How many miles on the chassis? Last time fuel filter was replaced? Did you get the walbro new or used etc..... More details on the fuel system please</TD></TR></TABLE>

On the b16a setup I was running over 80% DC. On my NEW setup I'm only running 42% DC. Sorry for the misconfusion.

As for the fuel setup, i'm using a new OEM fuel filter, new Walbro 255. I'm pretty sure the fuel system is not the problem.

Boosted_Coupe

Bump for some suggestions.

Tony the Tiger

My bet would be the cams... You could indeed have some other cams such as B16 instead of ITR's because that's one of the huge factors which contribute to your high RPM curve... Seeing that if you had B16 cams, it would explain the earlier torque gain with no top-end gains. Other than that, I can't see anything else that would go wrong with the list of mods on your car.

It would be great to invest in some adjustable cam gears so that you can shift the power curve around to see if the cams are the culprit to the problem.

DaveF

does your vtec activate ?

did you do a valve adjustment ?

Boosted_Coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaveF &raquo;</TD></TR><TR><TD CLASS="quote">does your vtec activate ?

did you do a valve adjustment ? </TD></TR></TABLE>

Yes and yes. I admit my clearences could be a little tighter on the valve adjustmeant, but it's not too loose by any means.

Boosted_Coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tony the Tiger &raquo;</TD></TR><TR><TD CLASS="quote">My bet would be the cams... You could indeed have some other cams such as B16 instead of ITR's because that's one of the huge factors which contribute to your high RPM curve... Seeing that if you had B16 cams, it would explain the earlier torque gain with no top-end gains. Other than that, I can't see anything else that would go wrong with the list of mods on your car.

It would be great to invest in some adjustable cam gears so that you can shift the power curve around to see if the cams are the culprit to the problem.


</TD></TR></TABLE>

Tony are you suggesting putting cam gears on my stock cams, or getting cams and gears altogether? Also I pm'd you.

Boosted_Coupe

Bump it up for some more thoughts..

DaveF

was the block or head milled ?

stock cam gears ?

was the timing sync'd properly ?

how much ign adv were you using ?

what ign system ?

what plugs ?

whats the gap ?

how old is the cap and rotor ? (if distributor? )

what a/f is your target?

how much fuel pressure ?

what fuel pump?

do you have a log of your fp curve ?

what map sensor ?

does it work ?

is it configured proper ?

DaveF

do you have a flex section in your downpipe ??

SovXietday

Dave, in with the possibilities.

Boosted_Coupe

was the block or head milled ? No & No
stock cam gears ? Yes

was the timing sync'd properly ? Yes

how much ign adv were you using ? will talk to my tuner tomorrow and ask him

what ign system ? Stock MSD wires

what plugs ? NGK #8s

whats the gap ? 0.028

how old is the cap and rotor ? (if distributor? ) Bought it last year OEM. Distributor is OEM aswell, but it's not new

what a/f is your target? I know my tuner was saying A/F is perfect. Not sure what the target was.

how much fuel pressure ? 50psi

what fuel pump? Walboro

do you have a log of your fp curve ? Will ask my tuner

what map sensor ? Motorola 2.5 bar

does it work ? yes

is it configured proper ? yes

Boosted_Coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaveF &raquo;</TD></TR><TR><TD CLASS="quote">do you have a flex section in your downpipe ??</TD></TR></TABLE>

Yes I do.

I'm meeting with my tuner tomorrow. He is going to give me a run down on how to use Neptune RTP on my laptop. Just the basics pretty much.