Problem making hp

[zexystang2]

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.

 

[Mustang30212]

Subscribing....good luck. I know its frustrating, but it'll work out.

Did you swap the sensors from left to right to eliminate them as the cause?

RH

 

[zexystang2]

When the sun comes out im going to try that. That'll be the last thing left before I try lockouts because ive tryed different vct solenoids.

 

[zexystang2]

I swapped the cam pos sensors and it still showed cam angle zero going erattic. So lockouts here I come. I know they say you loose some low end trque and top end hp but it cant be loosing more than im loosing now i hope.

 

[BruceH]

Just reread this thread and have a question. What is a 4.75 liter motor consist of? It sounds like an odd combination of parts. My next question would be how far were the pistons in the hole?

 

[zexystang2]

*Brand New STD bore (3.552) Cast Iron 2004 Cobra Block, torque plate bored and honed
*New Premium 4340 Forged US Made 4.75L Stroker Crankshaft w/micro polished journals at no extra charge
*New 4340 Manley H-beam Rods w/ARP rod bolts ( These US made rods are shotpeened, magnafluxed and weight matched to bring you the finest H-beam rod available)
*New Forged Manley pistons (High, stock or low compression)
*Total Seal file fit rings (precision file fit to your application, nitrous, blower, turbo or N/A)
*Clevite Rod and Performance Main bearings
*Ford Racing High Volume Oil Pump (installed)
*Complete Pro Assembly and Balancing for the smoothest, highest revving shortblock available,Pre-Lubricated with Royal Purple Assembly Lube and spin tested. Lastly 3 technicians sign off on your new engine prior to packaging and crating.

 

[zexystang2]

And no clue on the pistons I would have to dig up my sheet from mmr.

 

[BruceH]

The reason I ask is that one of my friends had a stock stroke block that was built with stroker pistons by accident. The motor just wouldn't make horsepower, it was down about 100 from where it should of been. Finally the motor was torn apart and the pistons were down in the hole alot farther than they should of been. IIRC the difference made his effective compression 7:1. Once the motor was reassembled with the correct pistons hp was where it should of been.

Did you measure the tdc piston depth?

 

[zexystang2]

The reason I ask is that one of my friends had a stock stroke block that was built with stroker pistons by accident. The motor just wouldn't make horsepower, it was down about 100 from where it should of been. Finally the motor was torn apart and the pistons were down in the hole alot farther than they should of been. IIRC the difference made his effective compression 7:1. Once the motor was reassembled with the correct pistons hp was where it should of been.

Did you measure the tdc piston depth?

When the motor arrived it was at tdc and it couldnt of been more than a couple thousandths. My hp trouble doesnt start till 4500 rpm when the vct is coming in.

 

[lito]

What happens with the boost then? do you have a boost curve to look at? Logs?

 

[zexystang2]

I didnt even have the tuner print the dyno sheet out because I was so pissed about the hp after buying a 1000 dollar turbo and making no hp. But on the dyno graph the hp climbs very good untill 4500 then it completely falls off at 5200.

 

[Surfstang2020]

Maybe some
Blower cams are in order ?


Sent from your moms phone

 

[zexystang2]

Maybe some
Blower cams are in order ?


Sent from your moms phone

I had comp 127650's in there and I was only making 400 hp. Blower cams dont work well with turbo setups.

 

[aleborjas]

the cams are not the problem stock cams make power on turbo, what i see off is the turbo back housing way too small you need like a .81 A/R maybe the engine is clogged at those Rpm's....
i've seen the cars go slower retarding the cams too much!

 

[zexystang2]

the cams are not the problem stock cams make power on turbo, what i see off is the turbo back housing way too small you need like a .81 A/R maybe the engine is clogged at those Rpm's....
i've seen the cars go slower retarding the cams too much!

I have a .81 a/r turbine now. I got a new precision 6766s up there now and still only made 481 at 22 pounds of boost.

 

[JoshK]

Not to get off topic but what does it change changing the cold side ar. My 6765 has a .81 hotside and a .75ar cold side. Also, what is the peak psi that that turbo is efficent at(I know psi is dependant to heads, cams, etc)?

 

[zexystang2]

Not to get off topic but what does it change changing the cold side ar. My 6765 has a .81 hotside and a .75ar cold side. Also, what is the peak psi that that turbo is efficent at(I know psi is dependant to heads, cams, etc)?

I have no clue. Lightblade probably knows though. I asked him most of my questions just to order this turbo. But I wonder if flowed heads are hurting me because lightblade has stock heads so does turbo pete. I havent heard of many turbo guys with aftermarket heads like me. I only got them because on my cousins procharged 06 they added 92 rwhp.

 

[lito]

There is something else going on, I suggest to forget about what mod is hurting you, something has to be mechanically or tunewise to do this, that is why data would help. Seeing that you reached 22psi somehow easily (I guess) suggest something is not right.

 

[zexystang2]

There is something else going on, I suggest to forget about what mod is hurting you, something has to be mechanically or tunewise to do this, that is why data would help. Seeing that you reached 22psi somehow easily (I guess) suggest something is not right.

Well I know something has to be mechanically wrong with the vct on passenger side because that cam angle is jumping from 1 degree to 18 degrees retard. And why would reaching 22 psi suggest somethings not right? I just turned my manual boost controller up to reach that. That isnt supposed to be hard.

 

[lito]

Well I know something has to be mechanically wrong with the vct on passenger side because that cam angle is jumping from 1 degree to 18 degrees retard. And why would reaching 22 psi suggest somethings not right? I just turned my manual boost controller up to reach that. That isnt supposed to be hard.

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.