NSXTC, do you have an NSX? Just wondering because of your nick

 

Experienced board members,Please take note to the last post I made last night and give me some direction as I am running out of time to make a decission on to take this thing to the scheduled Dyno Saturday or try another method to get this thing tuned. If this heat is a problem, I need to correct it.
Mark

 

No. Adjusting timing will affect torque which is a function of compression chamber effeciency.

If you have a stock combustion chamber, you would be well advised to use the stock settings.

My engine does not have anything stock. The heads were shaved by the previous owner, I cut an additional spark plug hole, the heads were fly-cut, a fire ring was added, and both ports were opened and matched to the other 5 - the entire geometry of the combustion chamber has been changed. For my engine, the stock AFR and timing values are guidelines. For example, at 1 bar, my total timing is 18 degrees, 12.9:1 AFR, 1575 degrees EGT, early flat torque at 470 lb/ft and 530 hp. I did a couple of runs at 13.2:1 AFR and got more HP and EGT's of 1625 - well within limits of the engine. Both Neil Harvey and Mike Bruns (together, these guys have more Porsche tuning experience than everyone on this list combined) encouraged me to keep that tuning map for peak performance, but my goal is to have a high performance car with excellent street manners - and longevity. So I went back to the 12.9:1 AFR.

Rgds

 

A pic for your viewing pleasure, this was last night after setting the timing and CO

 

I don't understand why your headers are turning orange at idle (I assume). Something doesn't seem right.

 

I'm planning to leave my rear bumper off for a while when I finish my project. I figure I can bolt the license plate where the rear reflector would go. It'll look kind of VW baja like. I should be able to get some good glowing turbo pics when it's on the dyno.

 

I should add that since that thread I started in 2005 about the red-hot headers, my new engine no longer does this. I check it regularly while it's still running during the cool down period and I'm not seeing any glowing.

 

NSX Pics

It's a great handling car, but no where near the HP of the 930 no matter how much $ you throw at it.

 

Yeah car is so easy to handle and great on the track. I got one that's been collecting a thick layer dust since I got my 965 EFIed. Wife says if I'm going neglect the H-car I should sell it. Shame but think I will since the 965 drives so well now (will decide once I try the P-car on the track for 1st time)

 

I really need to figure out why these things are turning orange at idle, I agree, it sure does not seem right.
Timing and the CO is set to specs, what else is there to look at?

 

I'm still not clear if it still glow after a few minutes of idle? Or constantly glows? I have to admit that's a pretty hot header. Mine only glows only in the area before the two halves meet and before the collector, but after idling even 1 minute, the glow goes away.

 

A bent exhaust valve that is not sealing would probably cause glowing headers as well.
What's your advance at idle?

 

The advance at idle is 5 degree BTDC if I understand the question. This thing will set at idle and just purrrr as smooth and nice as a new car. The only change I made was replaced the cams and added these headers, this car was driven alot before the mods and never a issue. All though it may have produced this heat before and with the Euro Exhaust I may have never known it.

Until I figure this problem out (if it is a problem) this car is parked.

 

Do they glow in normal daylight conditions? At idle, the pipes should be at a temp between 450 and 500 degrees F. I have a IR gun where I can take the temps pretty easily. Driving around the block normally will get portions of the pipes to glow a very dull orange, but it needs to be dark outside to see it. That is OK.

 

To be honest I have only ran and tuned the car at nite, not sure what it may show in normal daylight. The picture was take while pretty dark out. I will say I just fired it up, drove around for maybe 5 miles very easy, pulled back into the shop to see the headers glowing.

If there is a problem, the only thing I can think of is the Cams went in a little more advanced than the cam card called for, but John (camgrinder) said it was fine.
SC330 called for 1.8 - 2.0 mm / Installed @ 2.2 because that was the first Specs 2.2 - 2.4 mm given by John