2.0L Duratec Rebuild

[fastg]

I think your betting sticking to one dyno rather than shopping for the best numbers. Or you could spend you money on this, looks pretty cool 

 

 

[Vovchandr]

That's a clever piece of kit. Seems too pricy for the casual user who would want a tuner to do the tuning part while on the dyno, but very useful for anybody who would tune their own car. 

[JohnCh]

1 hour ago, fastg said:

I think your betting sticking to one dyno rather than shopping for the best numbers.

 

I'm not shopping for numbers.  I was simply curious how the older VRM dyno would compare with the newer one at CarbConn.  I didn't go to the latter first because I don't have confidence in their ability to tune a car based on prior experience, but I do have confidence in VRM.  The reason I'm now considering the shop further away with a hub dyno is not to see if the numbers go up, but if my hypothesis about wheelspin is correct.  Although I don't expect numbers to be the same from one dyno to another, I do expect the torque curves to have very similar shapes.  That's not the case here and it makes me curious.

 

-John

[ashyers]

John,

One thing that makes the hub dyno useful is the quick response. In certain tuning situations this can be helpful.

 

As far as tire slip and that type of thing, we've seen that the way the car is tied down can make a big difference. In a perfect world measuring tension on the straps would be helpful.

 

Andy

[JohnCh]

Thanks Andy.  The shop with the hub dyno is the one I initially planned to use to dial in the engine -- the operator really seems to know his stuff -- but COVID restrictions made that tough.  VRM filled the gap since my only concern at this stage was confirming timing at full throttle.  Drivability/part throttle mapping was done on the road through logging and the Emerald's adaptive, closed-loop function and is fine, so VRM's lack of a load-based dyno wasn't an issue.  However, for the new 2.4L engine in the Caterham, I won't have the luxury of a baseline map that is close and will have the hub dyno shop map that engine.  Getting a baseline of my current engine on their dyno would allow an accurate comparison of the torque curves between the two engines.

 

Unfortunately CarbConn has never met my expectations over the years, and this trip was no different.  First, they didn't bother to clean the big pool of coolant and gearbox oil on the floor from a car that went earlier that day.  On the surface, not a big deal, but to me it's a lack of attention to detail.  How are you supposed to know if your car is dripping during the runs when the floor is like that?  Second, the runs were all problematic.  The fourth gear run had the sine graph issues.  Not necessarily their fault, but annoying nonetheless.  The next run in third gear was fine aside from the apparent wheelspin.  During the next run, the engine stopped pulling at 6000rpm because they hadn't released the dyno brake (or at least that's what they told me) and on the fourth run, they forgot to hit record.  I could have gone for a fifth run, but decided to cut my losses.  It's a shame because they are the biggest facility in the area and have a recent 4 wheel Dynojet.

 

-John