2 October 2009
Session 312 - Rolling Road Tuning
Well today is rolling road tuning day. Will my engine survive the ordeal was on my mind for the first few hours. Well it did survive the only casuality was a slightly leaking rocker cover flange gasket. A word on this. The old style gasket was cork but the later design was rubber. The advantage with rubber is it is re-usable but I noticed when I installed these that it was soft rubber and hard to get to fit in the flange and when you tighten the bolts it moves a bit. I actually think the old cork gasket is better. So I am going to change them to cork.
Remember my engine hasn't been complete ran in. So the first hour on the dyno was used taking the engine on a light load and no more than 3,500RPM. Tuning also being done at the same time.The sound of a reving engine in a confined space and not moving is surreal.
After this run-in the real tuning began. Right up to 5,800RPM, full throttle, different loads, etc. This is almost the extent of my knowledge on the interesting topic of dyno tuning! Very interesting day watching Troy at Northamptom Motor Sport working magic before my eyes. You can quite literally see and hear changes in real-time as they are being made. I highly recommend Northampton Motor Sport for dyno tuning. They do all sorts of other things as well such as suspension setup, race day support etc. Anyway you can find them here.
Below is a photo of Troy at Work with lots of screens, controls, etc.
Troy made positive comments about the build quality of my car which was nice. I had two maps done, one with strict emissions to comply with the IVA and one optimised for smoother running.
I was expecting 280BHP as I have said before but this is based on other similair engines and taking into account the gains that should be released by the tuning mods I have made. However I set my expection to 260BHP! So I was really happy with the demonstrated 280.8 BHP! Even more impressive is the torque, just under 300 lb/ft or 406Nm. At jut 2000RPM the torque is 227lb-ft. As you can see the torque curve is pretty flat. I set a rev limit in the ECU at 5,800 as you can see from the curve it just drops off here. Had I gone for 6,200 probably show a little more power higher as maximum power is achieve higher than the standard Rover V8 this is due to the cam I have installed. So will allow me to get some easy additional power at a later stage. The standard Rockers arrangement of the Rover V8 has a maximum of 6000 before imminent failure. The bottom end can take higher, I believe around 7000.
I also noted the road speed and engine speed confirms the differential ratio of 3.36. Troy commented on low transmision losses was apparently is helped by the low gear ratio.
Here's a Dyno graph from RPi showing both standard power and torque expected from a Rover 4.6, the yellow curve for power and light blue for torque.
Below is the tabular data for my dynograph.
I checked the fluid levels after the engine cooled down. Oil level still on the max mark on the dipstick. Coolant level in header tank at the same level also. All that stick for 3.5 hours and running in I was expecting some oil loss. Tight.
I later reviewed the fuel settings.
Optimal fuelling map is shown below.
Fuel map to pass emissions shown below.
11 October 2009
Session 313 - More IVA specifics
3 hours
I have heard of possible failures regarding the hinges on the boot lid. So today I removed the boot lid and the hinges and ground the edges of the protruding hinge to comply with a 2.5mm radii.
Click the photo below to see a higher resolution version.
Thought I'd use up some spare rubber edge strip and light weight cloth inside the lid.
some more bicycle tyre inner tubing used to cover non-radiused edges this time on the headlamp brackets.
I also installed rubber trim on the edges of the scuttle at the sides under the dash. I also decided to use some light weight cloth on the inside of the skuttle to tidy up.
That's it every edge on the entire car now either covered in rubber or radii applied. Every exposed nut and bolt head capped.
25 October 2009
Session 314 - Even more IVA specifics
The Westfield fuel tank has deep recesses or dimples in line with the rear upper wishbone bolt. This recess looks like it would provide enough clearance in the eventuality that a Westfield is shunted from behind. There have been reports of fellow builders failing on this point.Westfield have produced a safety bar to help brace the tank and prevent it from being punctured. I spent this morning installing this brace.
So the only item now are the catalytic convertors. I spoke to JP Exhausts last week about this very topic and sent a few photos of the proposed installation point of the cataltyic convertors. They have requested that I take the car up to them to install to ensure maximum ground clearance is attained. Problem is that I have to wait until 30th November.
I also want to get the brake efficiency tested. I shall book into a MOT test station to do this for me.
I also addressed another annoying problem today. The digital fuel gauge would indicate more fuel in the tank when the engine is running. I suspect this to be a poor ground.I tested the current ground and it seems to be good however I suspected when the engine is running it is not. Funny things electrics. So I wired in a new ground to the fuel sender from the chassis, the same spot the battery earth is made. This rectfied the problem.
Go to November 2009