Exhaust teaser...

The Oily Bits S1 Specific Topics
21

Something else? Do tell.

22

ok dont take the pi$$…i run a rover tuning company
id be looking for something to fit on the rover 200’s and some metro’s!

Drew
Roverdose Motorsport

23

Ha! Nae problem.

24

cool, how far away from Aberdeen airport are you? as its only #20 return for me from Luton (which is about 5 miles from me).

Drew

25

you have pm Drew

26

An update on the fitment of Uldis’ race exhaust. I finalised fitment of this on his car on Monday.

I mentioned earlier that the system would run in a straight line to the rear valance exit - and so it does! Given the restrictions on silencer length that this layout imposes, I’m more concerned about the noise figures than anything else.
The silencer (straight-through design) is only 16" long and although 11.5" wide, this would not normally be enough to enable a 210bhp engine meet any noise regs. However, it’s actually noisier at idle than when revved! (This a function of the internal design - another cocked snoot at convention!).
I will post up the pics when I get them; I forgot my camera but the garage owner lent me his and promised me he would e-mail the pics once Tut has fixed his Broadband installation for him. Met Tut that day!

So this IS an exhaust teaser! Uldis isn’t back from hols till April 10th, so the RR work is on hold till then.

27

bugger

28

Before Uldis returns from Croft and posts graphs etc and everything kicks off - (well it has already on SELOC!) - I just want to claim the world record for an exhaust swap on an Exige. Tray off, my exhaust off (18min), EBD+Powerspeed back on - total 1hr 52min. Plus an oil change for the brother-in-law at the same time.

Erm, his car I mean.

29

Ok, some power graphs.

[image]http://img.photobucket.com/albums/v629/Uldis/Power%20Graphs/JV-EBD-short-longcomparison1.jpg[/image]

[image]http://img.photobucket.com/albums/v629/Uldis/Power%20Graphs/JV-EBD-short-longcomparison2.jpg[/image]

[image]http://img.photobucket.com/albums/v629/Uldis/Power%20Graphs/JV-EBDshortcomparison1.jpg[/image]


Now, the way to read them:

  • the top 2 graphs go to 8K rpm, don’t know why, printout glitch. This is why I included the graph at the bottom so you can compare how the curve looks and where it gets at 8.5K
  • the engine with the JV exhaust was running very lean from about 8000, so there should be acouple more horsies once that is fixed.
  • in the top two graphs, the green and red curves are the engine with the EBD exhaust, the only difference is: a) CRP without collapsed flexi section, b) longer trumpets that I made of plastic as a trial.

From analysing these two I would say that I was surprised to see the gain in torque all across the rev range, thinking that if the CRP collapsed section was at fault, then the very top would be freer as well, but as you can see, at 8K it goes back to normal, so I tend to believe this effect is due to the trumpets.

  • the way to compare the blue curve (JV) would be to the red one, since they had the same (short) trumpets. As you can see, the dip in torque at 2.3K is not there anymore but following that it’s down on torque until 6K, where it equals the EBD, and then it shoots off.


    As soon as I sort out my fuelling issue, I will try the JV with long trumpets.
    My guess is that this is going to be the best combination, approx 6 lb/ft of torque extra avg (as on the EBD) AND the top end.

And no, it’s not yet finished…

Stay tuned…

30

And here’s some more pics on the system:

[image]http://img.photobucket.com/albums/v629/Uldis/JV%20exhaust/Undercar1.jpg[/image]

[image]http://img.photobucket.com/albums/v629/Uldis/JV%20exhaust/2005_0329_075415AA.jpg[/image]

[image]http://img.photobucket.com/albums/v629/Uldis/JV%20exhaust/CNV00007.jpg[/image]


Of course it will all look different to this when it’s finiahed

31

Seems like as long as you keep the revs up it’ll be good

32

Now that’s a very nice K Uldis.

Ian

33

I like it…
For my new engine i think that it will be the best solution!

34

Uldis,

I’ve looked at your torque curves and you have lost sooo much low down torque (20lbft) and gained some torque (7lbft) and pub talk bhp in the last few 100 rpm.

I wager that on a given track, particularly one with a good variation in corner speeds, you will be out of that peak power more often than not and will really suffer when below 6000rpm due to the sacrafice that manifold makes.

Its done exactly as I said in my earlier posts - moved the torque up the rev range.

Its fine if you have a very very close gearbox where you can guartentee that you will be over 6500rpm at any speed, but you don’t have such a box AFAIK.

You’re better off not bothing with the manifold and spending your rolling road money on trumpet experiments. Try running very long trumpets on cylinders #2 and #3 and shorter ones on #1 and #4 and do a few different runs experimenting with lenghts.

I’d should also point out that your engine looks very much like its suffering from a leaking crank seal. This is evident from the oil coming out of the joint between your sump and gearbox bell housing.

Its a well know weak seal, and if not fitted correctly by your engine builder, will fail very quickly.

The seal uses a knife edge that runs against the crank. If the seal is fitted incorrectly, or isn’t lubricated with a light smere of oil, the knife edge will quickly wear and won’t seal.

Assuming the seal was fitted corectly and oiled, there could be a problem with the surface of the crankshaft that it runs on. Over time a groove is worn on the crank and if this isn’t micropolished out by your engine builder at rebuild time then its likely that the seal will quickly fail.

Another reason that the seal will fail is because of excessive crankcase pressure caused by blow-by - combustion gasses getting past your piston rings. This is genrally caused by ovalisation of the thin Rover liners. The ovalisation tends to occur because of the incorrectly counter weighted crank that causes the entire engine to flex, a particular problem at the very high rpm you’re using. You can partially solve this issue by using a Scholar EVO2 block that has thicker liners that are less likely to ovalise.

Liners also ovalise when the head is torqued. They may be round when not compressed by the head, but once the head is torqued they can go oval. The Scholar solution avoids this but simulation the head using a torque plate to compress the liners in the same way that the head compresses them. Once they are compressed, and potatially oval, they are honed to give them a round bore.

Not wanting to pick fault with your engine build - we all knwo who did that…

But you were sold on the idea of getting a well built, reliable engine, but it would appear that you never got one of these since attention to detail with some of the basic tasks hasn’t been achieved and you now need to relieve you excess crankcase pressure and prehaps replace the seal.

You can do this in a number of ways:

  • fit a dry sump with sufficient scavange to create a partial vacuum in the crankcase
  • fit a breather to the crankcase to vent the pressure in there, either to air or to the cam cover
  • increase the diameter of the breather holes in you cam cover
  • remove the gearbox/clutch/flywheel and replace the seal

SteveB

35

Thanks for the observations Steve,

and I have to clarify that it was me the first one who mentioned the missing torque in the midrange. That’s given, and this is not the final design.

But as mentioned on the post with the pics, the longer trumpets EBD curve gain could be transported to the JV cuve and have the top end, therefore it would get back the midrange (or some of it).
You have to compare the blue with the red, not the green. If you add 7 or so lb/ft all across and add them to the blue, you would be better off everywhere from 5K, after all, on track I am never below 5K, all from there would be gain.
And, see the big dip that everyone has with the std exhaust? (at the left of the graph) that does wonders to the driveability on traffic.

This is the next thing to try and there will be others.

And about the oil leak, thanks for the explanation, but I have a worse one on the other side: the oil cooler lines end fitting. But will check it.

36

You can try the longer trumpets with the short manifold, but they may or may not have the same effect as they did with the EBD manifold. Nothing is a given.

You need to consider the engine as whole and changes to one part (the manifold in this case) need to be tried in conjunction with cam timing and trumpet lengths to find the best all round solution.

Why did you not try the trumpets with the JV manifold onm the same day?

If I were you I’d download a copy of Cartest 2000 and put your EBD/trumpet power curve in and the JV power curve in and see which car is actually quickest…concentrate your efforts on the largest spread of torque (area under the curve) rather than chasing headline “pub talk” bhp numbers.

SteveB

37

Yes, I fully see the different effects things will have with the other.
This work is not finished, but some people were asking about the power graphs so there they are.
They will def. be different by the time we’re satisfied (are we ever?)

The longer trumpets and JV combination was going to be tried but it was decided not to just in order to see the effects of the manifold alone.
Better changing things one by one than several at a time.

Then there was no time that day to change to the longet trumpets.

And no, I’m not trying to get the max BHP, don’t worry.
I don’t even go to the pub

Want to get a better and linear torque curve from about 5K that decays at a certain rate at the higher rpm range. From what I see, on track I don’t really use anything below 5K.
And on the road, I actually never use full throttle or near full power. I find that I like to drive it more or less using 1/4 of the throtle travel, no more than half.

38

I guess I’ll have to repeat myself. I had a specific job to do - the headline figures were too important.
You could just as easily have pointed to the whopping 33lbft gain below 2500rpm, thus eliminating what must be a very serious “stumble”. What the manifold did is smooth out a horrendous looking curve. Peak horsepower figures are all about bragging and YES! I’m bragging about a 10bhp gain over the “ultimate” available at present.
You have bragging rights over an extremely impressive set of figures, after many, many hours of hard graft. This was our FIRST attempt.
Of course there’s room for improvement, that’s what R&D is all about. Watch this space.

39

Looking at the graphs I would have the EBD any day, been around in this game a bit too long to want pub talk figures. You will likely sell some exhausts off the back of the high peak power though and I’m sure that is your number one intention.

Good luck with the R&D, although most exhaust options have been tried already so best to start with a good search through the archives on here and SELOC.

40

what i like on uldis car is the straight back box that avoids the “S” usual on elises based cars.
What about to combine an EBD with the straight box?