Hope you guys can help, vh45 running rich

[Q45tech]

Don't confuse the after valve exhaust port temperature with the combustion space temperature:

"Cylinder head combustion chamber and piston temperatures and heat fluxes were measured in a 2.2 L 4 cylinder spark ignition engine. Measurements for the combustion chamber were made at wide open throttle conditions, 1400 rpm to 5000 rpm at 600 rpm increments, additional measurements were made on the combustion chamber at part throttle conditions at 3200 rpm. Piston temperature and heat flux measurements were made at WOT conditions from 1400 to 3200 rpm in 600 rpm increments. Average combustion chamber surface temperatures ranged from 130 degrees C to 248 degrees C, while peak combustion chamber surface temperatures ranged from 142 degrees C to 258 degrees C for WOT conditions. Peak heat flux at the surface for WOT conditions in the combustion chamber ranged from 1.2 MW/m\u2 to 5.0 MW/m\u2. Central region heat fluxes were 2.3 to 2.8 times greater than those in the end gas regions of the combustion chamber. Piston temperatures were 10 to 25 degrees centigrade hotter than corresponding combustion chamber surfaces at WOT conditions. Peak heat flux values in the end gas region of the piston were 2 to 4 times greater than corresponding locations on the combustion chamber at WOT conditions. The Woschni heat transfer model correlated well with the experimental instantaneous local heat flux data. Long term heat flux data indicates that deposit formation greatly modifies surface heat transfer. "from https://shop.sae.org/technical/papers/930217

[maxnix]

As has been said many times throughout the life of this board and its many previoius incarnations, if something works perfectly, don't change it unless you feel lucky. The PFRG look hardly used when they come out a healthy engine at 50K -60K.

One's time is better served experimenting with parts that may have room for improvement, if experiment you must. Thanks to Dennis, we know how to take these cars past 350K with little deterioration in performance. We also know only a very few select modifications will increase performance even slightly.

Speculatively armchair engineering someone else's car has no consequences for those doing the engineering.
Modified by maxnix at 3:10 PM 11/13/2008

[qship96]

The factory plug already outlasts the valve cover gaskets in a healthy engine too....so whats the point of trying to find an even longer lasting plug if you will need to be in there anyway replacing valvecover gaskets every 80-100K ???? Now if you could find a way to extend valvecover gasket life, maybe a longer lasting plug would be of some value????

My last set of factory plugs were in service from 69,000 miles til 203,000 miles{134,000 miles of use} and came out looking and operating well....the valvecover gaskets had been seeping for quite awhile by then.

[Infinitiguy19]

Sorry to go off topic, But with that much usage did you ever get any shakes at idle or even more when you rev the car in park or neutral to 2000 RPM's?

Mine shakes at Idle I know the plugs are due I just need to change them, have them on hand though so i am half way there.

I have 4 more MAF's to go though and check and 3 more FPCU.

[Unnatural1]

Speculatively armchair engineering someone else's car has no consequences for those doing the engineering.Modified by maxnix at 3:10 PM 11/13/2008

True enough...I really do not want to get into armchair engineering (because I'm not an engineer and I don't think anyone else in this discussion is either). We can pull up studies from SAE (or MIT or whoever) up all day, that don't necessarily pertain to the VH, and make claims of this is better than that (BTW my temp. figures are from the Denso spark plug website; I trust they know the temperature of the spark plug, flame, etc. is inside a combustion chamber).

My point, as I have previously stated, is you don't have to berate people for using a spark plug (of all things) that isn't the exact OE plug. THAT IS IT! That's the basic point I'm trying to make. It gets really irritating. No one is going to blow up their engine using NGK Iridium spark plugs specified for the VH45 by NGK.

NOW...HOW'S YOUR CAR RUNNING GS14RACER?!

[maxnix]

My point, as I have previously stated, is you don't have to berate people for using a spark plug (of all things) that isn't the exact OE plug. ..... No one is going to blow up their engine using NGK Iridium spark plugs specified for the VH45 by NGK.

First, not that I particularly care, but I don't believe I berated him by advising him he was not using the specified plug. If that is berating, then I am guilty. A car has to have at least one friend. And yes, some plugs (AC, Bosch, Autolite) have destroyed the VH45DE. Documented fact.

You may now leave your armchair, unless you want to stick around to read some of the previous posts.

[Unnatural1]

First, not that I particularly care, but I don't believe I berated him by advising him he was not using the specified plug. If that is berating, then I am guilty. A car has to have at least one friend. And yes, some plugs (AC, Bosch, Autolite) have destroyed the VH45DE. Documented fact.

You may now leave your armchair, unless you want to stick around to read some of the previous posts.

I'll leave my armchair when Q45Tech and you do. Also, I never said anything about AC, Bosch, or Autolite. Bosch plugs don't work in anything. I've replaced many poorly running Bosch plugs (Supers, Platinum, +2, +4, +whatever other marketing gimmick they come up with) in many different cars.
Modified by Unnatural1 at 12:59 AM 11/14/2008

[gs14racer]

Well just got back from the dyno, didnt change the programs really, just to check if it was running clean, And yes the timing issue was the reason it was running rich.

After taking the 5 degrees of advance i had out i lost a bit of power and torque down low, but its running clean now.

HEres the dyno pull, and theres one up to 7300 rpm just for fun, no power to be had up there though way out of efficency.

[Infinitiguy19]

When you did the Dyno run was the Q in 3rd gear right?

Thanks for the proof of no power at 7300 RPM's, I use to want mine RPM cutt off at 8000 RPM's just because the Tach goes that high.

[Rex]

When you did the Dyno run was the Q in 3rd gear right?

Thanks for the proof of no power at 7300 RPM's, I use to want mine RPM cutt off at 8000 RPM's just because the Tach goes that high.

IIRC, he's got the VH in a S14 (240SX) with a manual transmission. I'm pretty sure they knew not to use 5th gear.

The advantage of the higher redline in a Q45, is to maintain a single 1st to 2nd **** by the AT in the 1/4 mile.

[Unnatural1]

Still very excellent numbers. And now you are not wasting extra fuel to carbon up the combustion chamber. Are you planning on tweaking the ECM tune any further?

[Infinitiguy19]

IIRC, he's got the VH in a S14 (240SX) with a manual transmission. I'm pretty sure they knew not to use 5th gear.

The advantage of the higher redline in a Q45, is to maintain a single 1st to 2nd **** by the AT in the 1/4 mile.

Yea I totally forgot about the 240SX that the VH was in.

But with the raised RPM limit it would shift at WOT from 1st to second at about 50 MPH right? Then hopefully if you have it in second gear on the shifter AKA D-2, it won't shift from second to third thus slowing your quarter mile time, possibly costing you a race and a good time with a girl.

But can you keep it at D-2 on a Q45 without blowing the transmission or engine in the quarter mile?

[Unnatural1]

It's a 5 speed manual transmission. There is no D-2 range, only second gear...not automatic.

[Infinitiguy19]

Yea I know that its a 5 speed on his car, I was saying on my car though.

Sorry for any confusion, though my post was clear enough.