Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Minor Threat]

Here's a rundown on the setup

Built Y8
Ram-horn Manifold
T3/T61 turbo
3 inch downpipe
Tial 38mm WG
Golden Eagle Intake Manifold
Supertech valvesprings

Car previously made about 300whp on 17-18psi, peak torque was at 7800, peak power was right around the 8000rpm mark. This was with the stock Y8 cam.

This past winter we swapped the cam out for a Bisimoto 1.2 turbo cam, which was a complete and utter failure. Yanked the cam out, and put another stock cam back in.

The VTEC rocker arms had really bad wear to them, as did the cam itself so we put a different Y8 cam back in, and replaced the bad rocker arms.

The car makes more power than it did with the Bisi cam now, but it hits a wall at 7200rpm and just dies. You can see it on the dyno graph, hear it and feel it.

The only thing that's changed from last year is swapping the cams out, and replacing some worn valvetrain components, also went from Hondata S100 to Neptune.

I am confident that it's not in the tune, the timing is ok according the to dyno, as are the air fuels. Adding timing picked up power, but did nothing to stop it from falling off at 7200rpm.



Graph is WG spring, which is a 10psi spring that creeps to about 14psi up top as you can see. No boost controller, WG line is right off the compressor housing.

The graph is a little hamburger after fucking around with it so much, air fuels are a min of about 11.0 to a max of about 11.8.

What could cause the car to die at 7200rpm when it would make power to 8000 before, as well as be a down on power for the boost levels it's at?

[dvst8r]

First off I can barley make out the hp curve, can't see any boost line.

Is the cam out a tooth advanced?

[Robb]

Turn the boost up/down, see if it shifts with boost level.

[Joseph Davis]

To be a cock, I answered your HT thread.

[ratcityrex]

Is it a auto cam instead of a 5 speed?

[Minor Threat]

First off I can barley make out the hp curve, can't see any boost line.

Is the cam out a tooth advanced?

I'll fix that in a sec mspaint style.

Basically power climbs till 7200 then falls like a rock, while the boost keeps creeping up till
redline at 8100.

Cam timing is good, it's been triple checked and the dizzy isn't cocked one way or the other, it's pretty much in the middle.

Turn the boost up/down, see if it shifts with boost level.

It doesn't, we tried.

To be a cock, I answered your HT thread.

Jokes on you, while you were there you replied to a bunch of useless tards other than me.

Is it a auto cam instead of a 5 speed?

Are the SOHC auto and manual cams different? No idea what this cam came from.

[dvst8r]

Could be a boost leak, if the line for the wastegate is coming right off the compressor as you say. there could be a leak between that and the intake manifold, so if your seeing 14psi @ the manifold the turbo might be actually putting out 25psi+ and it is just running out of breath.

[Joseph Davis]

To be a cock, I answered your HT thread.

Jokes on you, while you were there you replied to a bunch of useless tards other than me.

Hey, you made the thread in the useless tard forum first.

[Minor Threat]

To be a cock, I answered your HT thread.

Jokes on you, while you were there you replied to a bunch of useless tards other than me.

Hey, you made the thread in the useless tard forum first.

You are incorrect sirrah, I made it here first then copied and pasted it there.

Pulled the VC off tonight, all the VTEC rockers and a few of the none vtec rockers are scored badly. Did I mention when we did the Bisi cam swap we changed some of the rocker arms over from a spare head, as the old rocker arms were super scored and worn, as  well as the cam lobes were starting to wear. Don't know exactly how long it had been like that, but the new rocker pads are just as fucked now as the ones we pulled out, and it's got maybe 2 tanks of gas through it?

Does anyone know the proper spot to tap the head for an oil pressure reading? I don't want to go jumping to conclusions but I think we're going down the road of something being up with oil pressure and dang ol vtec not working right.

Could be a boost leak, if the line for the wastegate is coming right off the compressor as you say. there could be a leak between that and the intake manifold, so if your seeing 14psi @ the manifold the turbo might be actually putting out 25psi+ and it is just running out of breath.

Did a ghetto check for boost leaks on the dyno, couldn't find anything.

We did:

Timing check
Boost leak check
Compression check
VTEC solenoid functioning check
Add timing
Add boost
Bypass boost controller
Checked turbo compressor for shaft play
Made sure TB was actually going wide open

[Minor Threat]

leakdown check and chexmix was not on that list

you fail

If the compression test comes out ok, why would I do a leak down test?

Also, you don't even have a turbo car.

[d112crzy]

The stiffer valve springs are what's causing the issues with the cam/rocker wearing. Try adding additives that are high in zing, or use Royal Purple or any other oil with high zinc content(or some mineral, ask bdvt).

Also..a wild guess why its not making power....bearings are going out. I've experienced this before on an lsvtec. The thing wouldn't make power after 7k. No boost leaks, compression test was great, afr's all under 12:1(only 9psi) and conservative timing. Then I noticed some metal flakes in the oil. I stopped tuning, the guy got half way home and said the motor locked up. Not sure what exactly went bad, but either a bearing spun or a rod bent is my guess. I experienced similar events with an H23 I tuned as well. Took the motor apart and a rod bearings were fucked(motor was a JDM motor with the supposed 40k miles, bs I know)

Either inspect the oil carefully, or crack open the oil filter.

[Joseph Davis]

Good point Jose, I'll comment on the HT thread.

[DmC]

Are you sure that you guys added the 9 degrees to the base timing?

[crttaz]

Z6 cam with a Y8 cam gear, 4.75 degrees advanced?

[Minor Threat]

Z6 cam with a Y8 cam gear, 4.75 degrees advanced?

This is possible.

Are you sure that you guys added the 9 degrees to the base timing?

Yeah, I added a lot of timing in the maps.

The stiffer valve springs are what's causing the issues with the cam/rocker wearing. Try adding additives that are high in zing, or use Royal Purple or any other oil with high zinc content(or some mineral, ask bdvt).

Also..a wild guess why its not making power....bearings are going out. I've experienced this before on an lsvtec. The thing wouldn't make power after 7k. No boost leaks, compression test was great, afr's all under 12:1(only 9psi) and conservative timing. Then I noticed some metal flakes in the oil. I stopped tuning, the guy got half way home and said the motor locked up. Not sure what exactly went bad, but either a bearing spun or a rod bent is my guess. I experienced similar events with an H23 I tuned as well. Took the motor apart and a rod bearings were fucked(motor was a JDM motor with the supposed 40k miles, bs I know)

Either inspect the oil carefully, or crack open the oil filter.

Stiffer valvesprings have been in the motor for the last 4 years. The vtec rocker pads were as badly worn in the last 2 tanks of gas as they were after 4 years. Something new is wrong, if nothing else the springs should've gotten weaker over time.

We're thinking oiling issue at this point, it is a stupid Y8.

[chris]

Valve spring theory with a single valve spring found on the aftermarket d16's is very weak speaking general terms compared to the aftermarket dual springs found in the b/h/k motors



My love for the d motor stopped at the y series. Oiling is a huge issue as it always is with those motors so the possibilty of it coming into play now is a possibilty.


Also did the bismoto camshaft go flat? if so that metal just didnt disappear its in the motor.

[Dr. D-Series]

Ive heard nothing but good things about the bisimoto sohc cams. 

Strange that you can a power loss issue. But I think its something other than the cam.

Do the rods that the rockers ride on have any heat marks by any chance ? Since you changed the rockers a couple times is why im asking.

Good luck figuring it out.

[Joseph Davis]

Ive heard nothing but good things about the bisimoto sohc cams. 

O RLY?

Now you've heard bad things from two sources.  Would you like a link to the three others I know of, that I ran across without looking?

[Minor Threat]

Ive heard nothing but good things about the bisimoto sohc cams. 

Strange that you can a power loss issue. But I think its something other than the cam.

Do the rods that the rockers ride on have any heat marks by any chance ? Since you changed the rockers a couple times is why im asking.

Good luck figuring it out.

There are a few people that have had issues with them.

Did not notice any heat markings on the rods the last time we changed them. I'll make sure to take a close look this time.

Valve spring theory with a single valve spring found on the aftermarket d16's is very weak speaking general terms compared to the aftermarket dual springs found in the b/h/k motors



My love for the d motor stopped at the y series. Oiling is a huge issue as it always is with those motors so the possibilty of it coming into play now is a possibilty.


Also did the bismoto camshaft go flat? if so that metal just didnt disappear its in the motor.

No, the bisi cam was out of the car after maybe 10 pulls on the dyno? It didn't even have the coating worn off it. It was the original cam that was worn, and it was more the rocker pads than the cam.

Thanks for the ideas guys, we'll get to the bottom of it.

[HiProfile]

Z6 cam with a Y8 cam gear, 4.75 degrees advanced?

Who's to say some retard 5 years ago got a z6 cam and put it in that y8 head you pulled it from? Advancing the intake lobes generally helps low/mid while killing topend. It also can artificially increase dynamic compression, so some detionation after 7k could be compounding it.

Even if it was a y8 cam, the worn followers (assuming they were adjusted before wearing) would provide a similar issue by reducing duration - opening the valves later & closing them earlier.

Otherwise it's some sort of bearing issue. Either the turbo is hurting (thrust bearing?), or an engine bearing is starting to follow Ed Mcmahon to the grave...

[Dr. D-Series]

Guess I havent researched the new bisi sohc cams enough. I just saw a couple dynos that looked promising against 59300 dynos.

I was looking forward to swapping to a bisi cam next year. Plans have changed.


Good to know. Like I said good luck.

[ryan89crx]

Guess I havent researched the new bisi sohc cams enough. I just saw a couple dynos that looked promising against 59300 dynos.

would they be the dynos from bisi's website?

[d112crzy]

A lot of the dyno's on his website are skewed, me thinks. Plus, the only one that spreads word on how awesome his cams are is himself. When asked to provide dyno sheets, he never responds or says he doesn't want to post them.

He's a little bitch, imo.

[chris]

Sadly the best sohc cams I ever used were Gude that fuckin old man has grinds that just hands down work. If his customer service would of been worth a damn he would of owned majority of the Honda market.




Bisi has spent his whole time racing he is not a business man and it shows. You cant have it both ways.

[crttaz]

You mean like the Gude flat lobes?

Also, if you sent in a Y8 core for grinding, who is to say you weren't sent a ground Z6 blank?

Came across same issue on a D15/D16 with a Bisi regrind.

Ended up being same 1/2 tooth advanced. Guy had to crank the dizzy all the way just to get 14 BTDC ignition timing even with the cam advanced!!!!

[Joseph Davis]

You also have to take into account that there is something.... alien... about some of the D-series.  Normally i see this on A6, but sometimes Z6 (D15B cam?), where you have to add 21 degrees to the maps to get ignition timing to come around.  They are a wierd fucking family of motors to work on because there's a lot of shit that interchanges and shouldn't.

[HiProfile]

Ain't that the sad fuckin truth. Around here, the retards use y8 gears because they look cooler. Last z6 I touched (besides my own) would max out at 13* with the dizzy adjusted all the way. The guy swore it was timed right, even after replacing the belt it was goofy. I was guessing a non-z6 cam, but he sold it & it bent a few rods before I had more time with it.