Problem making hp

[zexystang2]

A 6766 is not a huge turbo, making that boost on a perfectly flowing engine won't be that easy, if by some reason the engine is not moving air correctly boost will raise as it is more a measure of restriction than anything else. A locked cam will not cut your HP by that much, actually I've tuned quite some locked at zero retard cams without any issues.

Paul (againstallodds1) has stock cams locked at zero and ran mid 9s with a 76mm that comes with the hellion kit.

Well thats good to know. Because im wanthing to try 10 degree lockouts since im having vct problems on the passenger side.

 

[zexystang2]

I know a 6766 isnt a huge turbo. But lightblade made 655 at 16 psi with his .68 a/r turbine and now i have the .81 a/r so I just figured this turbo should be plenty for what i wanted

 

[lito]

Is properly sized for what you want, what I am trying to say is to look the boost you reach with a bit of salt, if you get high boost levels, it does not always mean that you have to see the corresponding power as something may be bad and not allowing the engine to move the air and hence the high boost as it is measure of restriction. Making 22psi out of this turbo on a perfectly flowing engine is not that easy, it may not get there and start to surge.

 

[aleborjas]

I know a 6766 isnt a huge turbo. But lightblade made 655 at 16 psi with his .68 a/r turbine and now i have the .81 a/r so I just figured this turbo should be plenty for what i wanted

a .68 a/r is small for a v8 with single turbo i dont think lightblade has that a/r making 655...

something is wrong in your car because with 22 psi you should be on 700 range!

 

[zexystang2]

Is properly sized for what you want, what I am trying to say is to look the boost you reach with a bit of salt, if you get high boost levels, it does not always mean that you have to see the corresponding power as something may be bad and not allowing the engine to move the air and hence the high boost as it is measure of restriction. Making 22psi out of this turbo on a perfectly flowing engine is not that easy, it may not get there and start to surge.

I know something is wrong thats what im trying to figure out with help from members. I've checked compression over and over and its still 150 on each. This is why im leaning towards the vct since that is the only thing acting up when i data log the car.

 

[zexystang2]

a .68 a/r is small for a v8 with single turbo i dont think lightblade has that a/r making 655...

something is wrong in your car because with 22 psi you should be on 700 range!

Ok well here is what lightblade pmed me directly " had a .68 and made 655rwhp. I just got the seals replaced and went to a .81 exhuast housing. I have a full 3" exhaust after the turbo." And kind of obvious stuff is wrong thats why i'm getting opinions on what people think it could be.

 

[RiskyBiznes05GT]

It has been to a capable shop and they have produced several 9 second 3v an 4v's. And I had a crappy on3performance turbo so a good one was needed anyways. So could someone who can actually help answer my question reply.
Cuz worst comes to worst i'm gonna order lockouts anyways. I just wanna know if timing can affect that much hp in boosted cars.

Wow, really you want to be a ass about it?! I was trying to suggest the most logical thing, considering we are not looking at your car/data/graphs or logs and your tuner has 100x more info about what your car is doing than any of us here. If you are going with 10* limiters, I would lock them out all the way and save yourself any possible troubles in the future.

 

[zexystang2]

Wow, really you want to be a ass about it?! I was trying to suggest the most logical thing, considering we are not looking at your car/data/graphs or logs and your tuner has 100x more info about what your car is doing than any of us here. If you are going with 10* limiters, I would lock them out all the way and save yourself any possible troubles in the future.

No im not trying to be an ass. But you did say take it to a capable shop and not to throw parts at it. I wont just throwing things at it and you didnt know what shop i was using. So your response was a little uncalled for. But im not even stuck on that. I am going to try 10 degree lockouts and i"m gonna try to find a way to post my data if I still cant make more than 481 rwhp.

 

[lito]

Do you still have the CMCVs installed? if so, are they opening up?

 

[zexystang2]

Do you still have the CMCVs installed? if so, are they opening up?

I still have the stock ones in. And how would I know? I'm looking on replacing these with the deletes anyways. But have others had problems with the butterflys not opening right away?

 

[lito]

Yes, and improper tuning makes them not to open too.

You can check them open with a log during a run, depending on what is set on the tune you can even check them opening while giving it gas stopped.

 

[JeremyH]

a .68 a/r is small for a v8 with single turbo i dont think lightblade has that a/r making 655...

something is wrong in your car because with 22 psi you should be on 700 range!

It worked fine at 16psi and 650rwhp, though that was about as much as I was comfortable running on a .68 turbine housing. And like the op mentioned I run a full 3" exhaust.


To the op I would def put delete plates in pronto. Not only will it eliminate this as an issue or solve it but its cheap insurance to protect your motor. The cmcv system and boost dont really get along too much anyways.

 

[crmpman2]

This is just a thought but maybe the stock manifolds are to restrictive for the heads that are on it. That with the fact of the erractic timing on the passenger side cam and the stock cmcv's. I have heard of N/A cars losing 50 hp due to a bad or erratic vct and the stock manifolds are probally choking it.

 

[RiskyBiznes05GT]

This is just a thought but maybe the stock manifolds are to restrictive for the heads that are on it. That with the fact of the erractic timing on the passenger side cam and the stock cmcv's. I have heard of N/A cars losing 50 hp due to a bad or erratic vct and the stock manifolds are probally choking it.

I doubt it is the manifolds, alot of turbo guys make good power on them. The vct needs to be fixed first, then address in other issues.

 

[zexystang2]

This is just a thought but maybe the stock manifolds are to restrictive for the heads that are on it. That with the fact of the erractic timing on the passenger side cam and the stock cmcv's. I have heard of N/A cars losing 50 hp due to a bad or erratic vct and the stock manifolds are probally choking it.

Since dyno tunes don't come cheap Im gonna do tuned shortys ,cmpd's, and 10 degree lockouts all at once just to rule all of it out.

 

[silverstang07]

Your tuner hasn't suggested anything? Sounds like you are going to waste some good money throwing parts at it. Sounds like you have a bad phaser or something with the vct.

 

[zexystang2]

Your tuner hasn't suggested anything? Sounds like you are going to waste some good money throwing parts at it. Sounds like you have a bad phaser or something with the vct.

He suggested locking the cams out and thats what im going to do. That way I dont have to worry with vct.

 

[silverstang07]

That's what I would start with. Have seen broken phasers do this a few times.

 

[zexystang2]

That's what I would start with. Have seen broken phasers do this a few times.

Did you see this on n/a or turbo cars? And do you know how much hp was lost?

 

[RiskyBiznes05GT]

Did you see this on n/a or turbo cars? And do you know how much hp was lost?

this happened to my car, driver side phaser lost its control of Cam. Beat the dowel pin out of the phaser and broke my cam shaft. This was with the comp phaser limiters. Big cams and vct don't mix well to me. In theory its great, but the weak point is phaser design (even with limiters imo)