My 2004R and an RPM issue

[Tom87GN]

Not sure if this is the root of the problem, but I've been tracking an RPM issue with my GN.

The darn thing won't rev like it's supposed to. WOT passes provide information that the motor only gets to just above 5000 RPM at the highest point.

Current mods are listed in my signature below. From what I know, this thing should run 11.60's at 114 and I can only get it MPH 110 at the most and haven't gotten quicker than the 12.05 that you see posted below.

I took her up to about 100 MPH last night, and the RPM's don't change much on the shifts and barely climb 500 RPM once in 3rd gear. This thing feels and acts like a diesel motor!

I have a data file from my PowerLogger, but couldn't successfully upload it to this thread for some reason. If anyone is interested in viewing it, I can send it to them.

My friends think it's a really loose converter issue. I was thinking I'd like to hear some other opinions, as the more eyes and brains on a topic usually yields more useful information.

Thanks to anyone who can shed light in advance.

 

[at7we2]

I'm no expert, but it sounds like possibly a valve-train issue to me. Have you checked the condition of the cam?

 

[2 QK 4 U]

with a stock cam isnt that all you're going to get?

 

[Tom87GN]

I'm no expert, but it sounds like possibly a valve-train issue to me. Have you checked the condition of the cam?

That is on the list, but I am really hesitant to pull the intake, as I have not yet upset the stock seals on the motor.

I have been suspect of the cam for a few years, but have never found any metal in the oil at all.

 

[Tom87GN]

with a stock cam isnt that all you're going to get?

I could be way off on this one, but I thought I've heard of plenty of guys going mid-11's on the stock cam??? If it is widely known that the stock cam won't take the motor much past where I'm at, then I'll concede and live with the low 12's.....until I blow it up or buy another motor.

Thanks for the reply.....it's much appreciated!

 

[2 QK 4 U]

I could be way off on this one, but I thought I've heard of plenty of guys going mid-11's on the stock cam??? If it is widely known that the stock cam won't take the motor much past where I'm at, then I'll concede and live with the low 12's.....until I blow it up or buy another motor.

Thanks for the reply.....it's much appreciated!

I was refering to the RPMs...there are stock cams in 10 second cars.

 

[Tom87GN]

I was refering to the RPMs...there are stock cams in 10 second cars.

So, in your opinion, with my combo, that's what I should expect from the stock cam?

Thanks again.

 

[2 QK 4 U]

So, in your opinion, with my combo, that's what I should expect from the stock cam?

Thanks again.

I would say the stock cam with good springs revs to no more than 5500 - 5600 at the most.

You are right. Your combo should be well into the 11's.

How are the valve springs? What condition?

Are you locking the converter? Is so when?

email me the powerlogger file.

 

[TurboDave]

The cam isn't going to control how high the engine's going to rev before it shifts. The cam only determines what kind of power you'll be making at a given rpm point.
Your shift points (wot) are controlled by the governor in the tranny, and if that hasn't been modified, then 5,000 rpm is perfectly acceptable and is what is normal.

See my comments over on the FTT site where you posted your PL file

 

[Tom87GN]

I would say the stock cam with good springs revs to no more than 5500 - 5600 at the most.

You are right. Your combo should be well into the 11's.

How are the valve springs? What condition?

Are you locking the converter? Is so when?

email me the powerlogger file.

The valve springs are new Comp Cams 980's that I just replaced a month ago. Not locking the converter. I will send you a PL file shortly.

 

[Tom87GN]

The cam isn't going to control how high the engine's going to rev before it shifts. The cam only determines what kind of power you'll be making at a given rpm point.
Your shift points (wot) are controlled by the governor in the tranny, and if that hasn't been modified, then 5,000 rpm is perfectly acceptable and is what is normal.

See my comments over on the FTT site where you posted your PL file

It doesn't seem like my combo likes to make power at higher RPM's....thus maybe not seeing anything over 5,100 RPM or so throughout the entire run each time.

I doubt that the governor was messed with during my rebuild. I didn't specifically ask them to do anything with it.

Does it matter that the 2-3 shift comes up much quicker than I expect it to? On the street, it will shift 1-2 normally around 15 MPH and then it will be into 3rd by 25 every time. I would think that it would climb to around 40 or so before shifting into 3rd. Ideas?

Thanks so much for your replies thus far. :smile: