Disappointing power from mods?
 

Hi all,

Performance question,
Just had my car dyno'd by a dynapac hub dyno the one jan at rmw prefers.

2006 R53

It has 17% pulley making 16 psi
RMW street cam
450cc injectors
RMW exhaust header
DDM works CAI
One Ball Exhaust mod
RMW custom tune

It made 172 whp!....

What? I really should have thought it would have made more... :(

Torque seems to be up there but lacking power.

Suspected belt slippage so changed to new belt which picked the psi up one to 16psi however it still doesn't have the go I expected.

Can I be missing something, I just checked the BPV too, good spring and it has an excellent seal at fully closed.

My brothers r53 just has the 17% pulley with none of the other mods and it easily keeps up with mine.

A little disappointing!

Yep, something's wrong with your car. If you post the dyno plots, I'll be able to tell if it's belt slippage. Even on a stingy dyno, like our Mustang MD250, you should show a lot more that 172.


https://cimg5.ibsrv.net/gimg/www.nor...2f74afd431.jpg

You read the dyno graph upside down ;)

There was some slippage on the dyno runs as you can see from these graphs. It was making 15 psi, we changed the belt and it went to 16psi, however 1 psi won't make a massive difference to the hp, maybe 9whp?

So I'm wondering even with the fixed belt whether something isn't right. As after I fixed the belt I did not notice an increase in power via the but dyno!

Dunno why they are loading upside down! Sorry :(

Argghhhh how annoying, they weren't taken upside down...

You have shown torque and fuel/air. It would be more informative in diagnosing belt slippage if you could instead show torque/power. Either way, I don't see clear evidence of the belt slipping in the shape of that torque curve. It looks like either the dyno operator is beginning the datalog at a very low rpm (sub 2K) or else the car is bogging at the beginning of the run. My guess is the former. You're not going to get any real benefit from starting the pull from such a low rpm. From 3k to red line (I see that you ran two pulls to 7.2k) the shape is what I would expect. The torque numbers are not way off. What was your peak HP number.

If you can look at the two previous posts there are two different power kW and torque graphs. Looks like it's making 130kw or 174 hp at wheels.

What's interesting is my brothers r53 with the 17% pulley but no header, cam injectors or tune keeps up easily with mine. Seems similar powered.

There is most definitely something wrong. I don't have the cam or the injectors and I'm getting 200 fwhp from Trackrat. You should be getting 220+ with your set-up.

I looked at the power curve and it doesn't have the tell-tale look of a slipping belt, either. Check your belt and replace it: it's cheap, but I don't think that's your problem. One interesting thing would be to datalog to see what your boost level is. You could do that on the street with a OBD2 datalogger, like the Bavarian Technic tool.

https://cimg6.ibsrv.net/gimg/www.nor...8fbebf7eb9.jpg

16psi with the data logger after changing the belt. Maybe I should do a compression test, although it felt string before doing any mods. Perhaps I messed up cam install too...

16psi sounds about right. If you have significantly deteriorated compression, you'd probably be throwing a P03XX code of some sort or you'd be consuming oil severely.

It's using a bit of oil, not heaps, maybe 100ml per two tanks of gas. Thought that's just a mini thing but!

Perhaps the cam could be mistimed? Anyway I can check it with compression?

Thought if it was mistimed it would idle wrong, all it has is a tiny lope every ten seconds so thought all was ok!

Recent spark plugs? Any ping? What octane fuel? How many miles on the motor? Injectors...are they re-drilled?
That HP seems low...
Then again....the guy that was on the dyno before me had meth, a cam, and 450, and a 17 and did 170...
I went next with a stock exaust, jcw 380's, and a 17%... i did 200 hp...I was happy with jan's job...he was like..with an exaust you could have hit 205, maybe 210 if you had bigger injectors...

Recent spark plugs with pulley upgrade before cam etc. was working fine. One shade cooler as per recommendations.

95000kms, so low mileage motor. No pinging..

your torque number seems a tad low as well. I wonder if your a half a tooth off on cam timing, not enough to throw a code, but enough to affect performance,


compression test wouldn't hurt


also what wheels and tires are you running? very heavy wheels will rob some power

What will timing off show up as in a compression test?

How do I retime it? Can I leave the cam bolted in and move the chain around the top and bottom sprockets? I believe I have to remove crank pulley and cover to see bottom of the chain?

Can I just hold back the tensioner and move the chain to correct location? Does engine need to be TDC when I do this or can I just put the chain copper links opposite the marks top and bottom?

I like the off-a-tooth theory. You'd be down about 25 hp but not misfire and show consistent compression cylinder-to-cylinder.

Remove the spark plugs, pop off the valve cover, set the engine to MDC with the factory tool, and us a long quarter-inch extension as a feeler gauge to measure the position of all of the pistons. If #2 and 3 are not the same as #1 and 4, there's your problem.

Sorry to be a pain, you have been hugely helpful. MdC is?
So number 2 should be same position as number 1 and 3 the same position as 4?

I think this theory has merrit :)

Can I do this without the factory tool?

MDC: Middle Dead Center. It's the position that you put the motor when removing timing components such as chains, cams or lifters. For your purposes, you're really going to need the tool. It can be done without it, but precision dictates that you get it right.

The MINI engine's crank configuration is setup a little like a (twin) two cylinder motor. Cylinders 1 and 4 move in the same position, and 2 and 3 move in unison. Hold your hands in front of you and make two thumb-n-pinkie hang ten signs. Now rock them back and forth like a California surfer with your two thumbs moving up and down at the same time. That's how your cylinders move.:thumbsup:

Best description ever! I love it :)

Is the tool I need the cam locking tool or another one?

Yep.

One last question if I can.

With this tool on, do I have to loosen the cam bolt or can I somehow move the chain with it all tightend up by pushing back the chain tensioner?

Try removing the tensioner and pulling the chain tensioner guide rail. That'll probably give you enough play in the chain to slip it over the teeth.

Awesome,

And the bottom crank arrows go at 3 pm and 4pm with the copper links.

And the top crank has an arrow which is locked in place by the tool which points to the final copper Link.

This is how I know I will have correct timing right? And if the bottom one isn't aligned then I can just turn it to the position I mentioned.

Sorry for the waffling, you have been maaaaaasssively helpful. I'm just trying to piece all the knowledge into one post.

Cheers