Got a new dyno tune and put down 381RWHP and 358RWTQ SAE through the 9" and Truetrac. This was an improvment over my last setup that used mid-tube headers and smaller injectors. The tuner is convinced the tune is optimized and dead on. We beat on the fuel and ignition for hours and the numbers moved very little. The engine has none of the valve float that was biting me in the *** last year as many of you may recall. I have a speed density tune that made 384RWHP /360RWTQ also.

Red = previous setup with mid-tube headers & 30# injectors
Blue = current setp with LPP long tube headers & 37# injectors


Look at the little (blue) torque hump at 4K RPM as compared to rest of the (blue) torque line. Is that bump a "bonus" or is there a torque defficiency from 4K - 5K RPM or so? I was expecting a nice crown or so.

Car runs very strong and screams to 6.4K RPM when you beat on it and drives like stock and I do mean stock when cruising around or going to the grocery store. I am not detecting anything at all to raise any concern that something is wrong or not working right. Going to the track in April, I hope.

Does this graph look normal?
Comments?

 

Starting @ 4k and ending at 4.25k I had that same lull. On the other hand, mine picked back up at 4.75k and increased (approx 10 ft-lbs more than at 4k) . I was told it was the way the stock (ported) heads flow. Somewhere I have the graph. I'll see if I can find it.

 

here it is

 

I see what both of you are saying, but also what you have to realize is they both have a huge fat torque curve, it really stays the same across the board and thats what ya want.

I am and would be curious as to what some of the others would attribute this to, but I have seen it many times before and I have never really bought into it being anything bad just rather noticed the good broad band.

 

We tried like Hell to round over that TQ curve. Nothing worked and we tried for hours.

 

Nothing you can do but get better heads (is what I have been told).

 

If whoever told you that is to be taken as creditable, then he should provide a valid and detailed explanation why a stock ported head could do this. Might as well blame it on the opti.

 

wow....talk about shooting the messenger

 

My bad. Did not mean it to sound like that. It just sucks when one starts implying the heads are ****.

 

Could be the headers. I'm sure the "harmonic tuning" is different from the mid tubes.

 

Glad to see you got it done Bill.....thats almost the exact numbers I put down before my change...like to get mine put back together and get her re-tuned and see the difference if any.....but very interesting.

 

Also looks like it might be flat lining a bit at 5.8RPM or so. Any ideas why?

 

I saw that.....makes me wonder if we are running out of flow......and the cams are working right, but not enough flow in the heads to keep up......I have no ideal....was wondering what you thought.....do you know what your heads flow, because I have no ideal, mine were not put on a flow bench after they was ported....so I will be completely in the dark there......call me when you get a chance.....want to get your thoughts on something.

 

 

http://www.cardomain.com/ride/2567183/7

scroll to bottom for graph