A good morning at Blink Motorsport

[AdamR]

Note: This is a long post! In short, Blink did a great job on my car, finding 10% more power pretty much everywhere, worked with great attention to detail and at a price I was actually a little shocked at (cheap!). They aren't happy though and would like me back once they have completed their new dyno cell.

Evening all,

 

As some may know, I've been spending quite a lot of time researching and tinkering with all aspects my car recently (one of the links is here), and ended up heading down to see Fraser and RIchard at Blink Motorsport today.

 

I'd been to a rolling road a few weeks back to check the car was running ok, but it turned out it wasn't despite the operator telling me it was!

 

Anyway, despite the snow I managed to arrive at around 9:15 and was welcomed by Fraser and offered the usual cuppa. As I'm a bit of a camel I declined, but we spent a few minutes discussing what we wanted to achieve and looking at the previous plots I had for the car.

 

The previous rolling road I went to was a 'true' rolling road - big rollers built into the floor which were driven by the rear wheels. It's pretty scary seeing your speedo up around 130mph but the car going nowhere, your brain goes into 'what if' mode...!!!

 

However, Blink's setup is a Dynapack which uses two independent 'pods' attached to the driven wheels via a bolt-on splined system. This seems much safer to me, and also isolates the tyres from the equation, thus measuring the torque at the driven hubs directly.

 

 

So, once you have the gear ratio (1:1 in my case - 4th gear) and the diff ratio (3.92 on my car), you can work out exactly what torque is being produced at the hubs. So, if the dyno measures 392ft-lbs, the torque produced by the engine is 100ft-lbs because it has been multiplied by the gear and diff ratios (note that is simplified, there are drivetrain losses to take into consideration - more on that later).

 

Someone once gave me the analogy that torque is how hard you can punch, and bhp is how many times per minute you can throw that punch. So - rolling roads / engine dynos measure torque (not power!), but from torque and engine rpm you calculate bhp: BHP = Torque x RPM / 5252 (which is why the bhp and torque curves are usually seen to cross at 5252. Apparently this is not really true but I've forgotten the reasons! Fraser!?).

 

The repeatability of this system also appears to be excellent (helped by removing the rear tyres from the system, which transmit the torque differently depending on temperature and can slip on 'normal' rollers).

So, onto the tests... Once the dyno had been calibrated and the car warmed up, we went for a power run. The main things were were interested in were the shape of the torque curve (a flat curve gives a 'driveable' car) and the AFR (air : fuel ratio).

From my understanding (please feel free to skip if you know or this or correct me where I'm wrong!), the AFR is important because it dictates how efficiently the car is running.

Lambda 1 is said to be the most efficient way of burning fuel, eg. you get the most energy out of it. This an AFR of 14.7:1 - therefore for every 14.7kg of air going through the car, there is 1kg of fuel. This is why you use a lambda sensor in the exhaust to check the AFR.

If the AFR runs too 'lean' - a higher number, say 16:1 - that means there isn't enough fuel and the amount of fuelling should be increased if possible (or you need less air - but nobody wants to reduce that as it reduces the power of the car!). If the car is too lean this tends to have nasty effects to the physical bits inside the engine - as well as powering the car the spray of fuel also cools the system, so being too lean is bad! You can eek a teeny bit more power out of the engine by running it right on the edge of too lean, but for a trackday car that's not wise.

If the AFR is too 'rich' - maybe 10:1 - you need either more air or less fuel. It's hard to get more air so you tend to reduce fuelling instead. With a car that's too rich, the throttle response is poor and it can be described as 'boggy', which reduced power and fouls up the spark plugs with the extra fuel.

However, we don't aim for 14.7:1 everywhere because that is too lean for a car. Something around 12.5:1 or 13:1 for a naturally aspirated engine is about right, whereas some turbo cars might be as rich as 10:1 as they need the extra cooling.

(I realise the above is slightly simplified but I don't fully understand the intricacies and just wanted to offer an overview as hopefully people will find it interesting.)

When mapping a car you run through all the different RPMs and all the different throttle openings to try and get a good AFR throughout - this is why it takes some time and it's worth paying for it to be done properly!

So, here's the first two runs - repeated to confirm accuracy...

As you can see, the car was way too lean, especially at around 3500rpm (although Richard believes this to be an effect caused by hammering the throttle wide open to start the run), 4800rpm and 5700rpm.

The first two runs gave this sort of power plot...

As you can see, there is a significant drop in torque (left plot) and therefore bhp (right plot) at the points where the car leans out. So, by being too lean it was endangering the engine AND robbing me of power!

The yellow and green boxes at the bottom of the screen show the repeatability of the results too - the green showing a slightly higher result since the gearbox and diff oils warm up with use and therefore reduce the torque losses in the drivetrain. It's possible to estimate these though - more on that later.

Back-pedalling a little.... Getting the car rigged up was fairly tricky due to the wide rear arches and exhaust position - but luckily the guys were prepared so had a heatshield and some cloths (to go behind the heatshield) to divert the exhaust gasses away.

However - my exhaust decided it would blow a hole in the heatshield, set a cloth on fire and melt the paint on both the dyno pod and the floor (SORRY!!). So, Richard ended up removing the end of the can, pointing it upwards and removing my rear arch. It was great to see a company spending the extra time to do this, and constantly being concerned about melting my bodywork or scratching the arches. At the start Richard also ensured the dash was set to show both RPM and oil pressure - I guess this is sort of obvious thinking about it now, but it was great to see someone taking pride in their work (rare these days!) These little touches really make the different IMO.

 

Anyway, back to the mapping. With Richard in the seat and Fraser manning the laptop next to him, they first increased fuelling throughout the rev range and then performed a couple of 'fixed rpm' runs at full throttle - with the dyno holding the engine at a fixed speed and then adjusting the fuelling in real time to tweak those lean spots. The results were pretty impressive! Note: The previous plots I have for the car show decent AFRs, but I think this was done before some extra breathing mods were fitted to the car, or the lambda sensor used before wasn't calibrated correctly. It can be shown that Blink's is calibrated correctly by the fact that I have added more fuel and it increased the power - if the engine was made too rich this would have decreased power.

So, after just over an hour including fiddling time and letting the car cool down, the AFR was reduced to a much safer level, which increased the power of the car by almost 10% throughout the rev range! The dashed plots is before, and the solid plot after. Blue is AFR, Red is torque and Green is bhp. The slight oscillation on the graph may be down to my throttle bodies, which Richard thinks need an extra spring as the throttle is a bit light - that's how sensitive the dyno is!

The power shown there is at the hubs, and generally for most rear wheel drive cars on this system Fraser tells me you can multiply the bhp by 1.25 and the torque by 1.18 to give 'at the flywheel' figures. That estimates the engine at approx 260bhp (up from around 235bhp) and 189ft-lbs (up from 177), plus safer AFR

 

At this point a chap from next door came round and mentioned noise and smell, so we had to call it a day. The chaps have invited me back to continue the work once their new sound-proof, insulated and extracted dyno cell is completed though - looking forward to it!

 

 

Because I was so impressed with the work so far, I asked if there was anything else I could pay them for while I was there... Well, Fraser had been really kind in offering advice to me when I was researching geo setup, and they have a super posh alignment machine installed (link), so for £25 I thought it would be rude not to get it checked out!

The car went up on the ramps, had the targets added to the wheels and occupant-simulating weights were loaded into the seats...

The results of my home geo were actually pretty good - but you can tell the machine is on a different level. Just shifting the car around a bit would change the real-time measurements on the screen, so Fraser showed me how the rear wheels toe out slightly under acceleration, and how the camber changed with bumps / body roll - interesting stuff as it tied in exactly with the stuff I had been up to in my setup thread.

 

Anyway, here's the results:

I had been aiming for 2.6 camber up front, about 2 at the rear, 25 mins toe in at the rear and parallel front, so it's pretty close! I do need to toe that left rear in a bit though (half a turn on the rose joint), and ideally get some rose jointed top wishbones up front to level out the caster (the car appears to have been in a bump ). Because of the mis-matched caster I'd attempted to set the toe to zero or it would drive to one side all by itself.

Goes to show that a bit of care and attention with the 'string method' and a spirit level doesn't give bad results if you take your time! I have a feeling my floor is 0.1 degrees out ((leaning to one side) so I shall have to take that into account next time...

So - to sum up - really good service from the guys at Blink, at a price I was genuinely not expecting. Thank you!

 

 

Oh, and one last thing - when Richard removed the end cap on my silencer to turn it round, 4 of the bolts were done heads and one was a cap head. I don't know if it was by chance (I doubt it, as the chance is 5:1), but the way he fitted them back in was with the cap head hidden underneath the car out of view. That sort of attention to detail says a LOT about a company I think. I shall be back!

 

Cheers,

Adam

[WINGNUT]

That sounds like a good constructive day out! Wouldnt mind one like that myself! Better get to the petrol station for some flowers for the wife

 

Wicked post that mate was a top read

 

Scott

[Dommo]

Good post - thanks for that

 

And indeed, kudos to the guys at Blink!

[KugaWestie]

Adam, great post, thanks.

 

Great work by Blink, this just gets me more excited about my project with them!

[Pistol Pete]

Great post! You appear to be able to relate theory to practical information very well - i think a few ww articles might be in order.

I first read that description of torque/bhp in ride magazine then heard it the following weekend on the intro by m brundle of one if the monaco gps (he referanced that he'd read it in a bike mag).

[Martyn Vann - Warwickshire AO]

Great post, looks like a very productive day and a job well done by the guys at Blink. 

[FILFAN]

Good result Adam.

What have you done to your engine as I like those figures

[XTR2Turbo]

Good post Adam.

It does show how careful you need to be when deciding where to get a car mapped and sometimes a bit of a drive is worth it.

[Meakin]

Very informative post and I'm very impressed with blink's service. Thank you

[Burlers]

Thanks for a great post, really informative and perfect reading for us petrol heads. Nice one

[SootySport]

You learned a lot Adam, I would have forgotten 90% of that info by the time I made it home.

My interpretation of BHP/Toque is.

BHP----How fast you hit the wall.

Torque--How far you carry on through the wall.

[1313]

I'm booked in at blink on the 12th April for a map brillent service from fras and Richard they transformed my car when they sorted all the suspension up

Would recommend this company to anyone

[Onliest Smeg David]

Hey, come on now...

If everyone gets to hear how good BLINK are....

they won't have any space left for me to book mine in next time!!

[Onliest Smeg David]

Hey, come on now...

If everyone gets to hear how good BLINK are....

they won't have any space left for me to book mine in next time!!

[Paul Aspden]

Just one query, how the heck does a transmission loss equate to a percentage of the power?

 

My point is, two westfields, both with exactly the same gearbox and diff ratios have wildly different horsepower figures, the x flow car has 100bhp at hub, the duratec has 250bhp at hub, yet if a percentage calculation is used to get a flywheel figure, then the duratec as over twice the transmission losses from the same transmission.....