Cosworth Supercharger Owners Thread

[sly]

Originally Posted by botbs

Hi all,

Matt @ cosworth helped me a lot on the tune. However, I am on the 6th tune now and still have knocking at 5000rpm. I kind of give up because it cost me a lot for the shop flash and test again and again.

Matt noted that mt vehicle (2018 brz ts) may have a more restrictive exhaust and canadian 94oct fuel may not as good so knocking still exist.

I need suggestions from you guys, shall I ditch the cosworth supercharger and call it a day. Or shall I take the risk to buy full exhaust (header and catback)

I am also getting a little spark knock above 5,000 rpms. Running smaller pulley on a 2016 BRZ with the Cosworth Exhaust except I retained the factory header. Eventually the ECU compensates for the spark knock but it's not entirely smooth when it does it. I noticed my advance multiplier was down to 0.43 and when I hit 5,000 rpms under wide open throttle, the car would feel a little jerky like it was climbing a stair case. I believe this is the ECU learning where the spark knock is occurring and is pulling back timing, but not smoothly.

If I reset the ECU and take the advance multiplier back to 1.0, I get significant spark knock initially when under WOT at high rpms. I'm not sure if the car is entirely happy with the smaller pulley.

[nikitopo]

Originally Posted by botbs

Matt @ cosworth helped me a lot on the tune. However, I am on the 6th tune now and still have knocking at 5000rpm. I kind of give up because it cost me a lot for the shop flash and test again and again.

In what gear are you doing the log?

[sly]

Originally Posted by sly

If I reset the ECU and take the advance multiplier back to 1.0, I get significant spark knock initially when under WOT at high rpms. I'm not sure if the car is entirely happy with the smaller pulley.

I may have spoke prematurely. Looking over the log again, Matt seems to think I have a vacuum leak. So I'm going to grab the propane and an air compressor and check the intake and exhaust and get to the bottom of this. Long term fuel trims were calling for about 25% more fuel. So something's up...

[Matt@Cosworth]

Originally Posted by botbs

Hi all,

Matt @ cosworth helped me a lot on the tune. However, I am on the 6th tune now and still have knocking at 5000rpm. I kind of give up because it cost me a lot for the shop flash and test again and again.

Matt noted that mt vehicle (2018 brz ts) may have a more restrictive exhaust and canadian 94oct fuel may not as good so knocking still exist.

I need suggestions from you guys, shall I ditch the cosworth supercharger and call it a day. Or shall I take the risk to buy full exhaust (header and catback)?

If go for header and exhaust, any recommendations? I want a reliable set up and prefer equal length catted header/exhaust.

Thanks!

the amount of knock you were left with is well within normal limits, if you take a look at how much the standard car knocks you'll see your car is now less than the 4-5° they commonly trip the ignition fine correction by

so your car should now be safe.

however going for just a catback I think would also pay dividends as the OEM backbox is quite restrictive

[gtengr]

Originally Posted by mrg666

There is no evidence without pictures!

Attached. Still a few things to clean up and zip tie at that point.

The other pic is of the fuel connector bracket that I cut instead of using the aftermarket fitting. I preferred keeping the factory fitting and buying it again to go back to stock rather than mod the line. One of the radiator brackets requires a mild trimming too so the tools for cutting that bracket should already be on hand.

Driveability-wise it's feeling pretty good. I added a clamp to every vacuum hose on each end and haven't experienced any serious driveability issues in the first 400 miles. The only thing is it feels like I'm having to relearn the clutch, and I'm not sure if it's supercharger drag on the engine that's changed it, or if the ecu just needs more time to learn. It drives fine otherwise. Interstate mpg dropped from 34.5 mpg to 32.7 mpg (as measured on the trip computer), and the low-rpm power in the upper gears is much better for passing and higher speed driving in general. The only other power mod is the Ace CS400.

[botbs]

Originally Posted by Matt@Cosworth

the amount of knock you were left with is well within normal limits, if you take a look at how much the standard car knocks you'll see your car is now less than the 4-5° they commonly trip the ignition fine correction by

so your car should now be safe.

however going for just a catback I think would also pay dividends as the OEM backbox is quite restrictive

Thanks, will buy a cat-back ASAP!

Any cat-back would work right? Most likely going for this, Thanks!
https://www.blitz.co.jp/products/exsystem/nur_fti.html

[Matt@Cosworth]

in terms of power as long as its at least 2.5" diameter pipe and straight through silencers then they are all very close

however in terms of noise they are very different
Ti systems are very nice but expensive and with the charger you're shifting a lot more air than stock so I'd consider something with a larger silencer volume if you want to save your eardrums

[NOMAD86]

Hi Guy’s,

Haven’t posted on this forum before, but I’ve been reading along for quite a while now (I know sneaky me...).
I’m running the supercharger for almost 2 years now and about 6 months ago upgraded to the smaller pulley.
Accompanied by the smaller pulley, I’ve installed a BLITZ SUS power intake (really brings out the nice SC sound…) and an upgraded fuel pump – rail – injectors.
As for the exhaust the car has Tomei UEL headers, Tomei over pipe, Berk midpipe and TRD cat back.

Now I track my car on some occasions, and I find myself in need of a little extra ‘umpf’ to catch some of the highly modified and high-power street cars on the straits. No issues in any of the turns as the car is beautifully balanced.

Since I’m already on the smaller pulley, I don’t know how to proceed with getting more power out of this kit. I want to stay SC as I dislike turbo kits on tracks for drivability.
I know I need to go forged internals, at least the connecting rods and might even consider stroking it to 2.1L. But this will not bring me much extra power, so how would one manage this?
I don’t just want it to be fast (it already is fast), I would like it to be a little super charged rocket. I know I’ve already done all of the accompanying mods to chassis and brakes to make this work. Let me know your thoughts!

Cheers

[weederr33]

Originally Posted by NOMAD86

Hi Guy’s,

Haven’t posted on this forum before, but I’ve been reading along for quite a while now (I know sneaky me...).
I’m running the supercharger for almost 2 years now and about 6 months ago upgraded to the smaller pulley.
Accompanied by the smaller pulley, I’ve installed a BLITZ SUS power intake (really brings out the nice SC sound…) and an upgraded fuel pump – rail – injectors.
As for the exhaust the car has Tomei UEL headers, Tomei over pipe, Berk midpipe and TRD cat back.

Now I track my car on some occasions, and I find myself in need of a little extra ‘umpf’ to catch some of the highly modified and high-power street cars on the straits. No issues in any of the turns as the car is beautifully balanced.

Since I’m already on the smaller pulley, I don’t know how to proceed with getting more power out of this kit. I want to stay SC as I dislike turbo kits on tracks for drivability.
I know I need to go forged internals, at least the connecting rods and might even consider stroking it to 2.1L. But this will not bring me much extra power, so how would one manage this?
I don’t just want it to be fast (it already is fast), I would like it to be a little super charged rocket. I know I’ve already done all of the accompanying mods to chassis and brakes to make this work. Let me know your thoughts!

Cheers

What about finding ways to lighten the car? It would give the illusion you are quicker. Or, if you have it readily available in your country, E85 will help too. You could always mill a smaller pulley, but would need a larger crank pulley if I remember correctly. But that could be a lot of work.

[NOMAD86]

Originally Posted by weederr33

What about finding ways to lighten the car? It would give the illusion you are quicker. Or, if you have it readily available in your country, E85 will help too. You could always mill a smaller pulley, but would need a larger crank pulley if I remember correctly. But that could be a lot of work.

Car is already lightened with rear seat delete kit and some Sabelt seats. Don’t want to go full monkey cage and bare metal interior though.
Could maybe shed a little weight more but no substantial gains there, I think.

E85 is not available, but we do have 102 Octane 'race' fuel available, so could gain a little there.
I thought a further smaller pulley on the SC is not possible?
Bigger crank pulley sounds like an option...but how big and don’t you run into rollers and tensioners down there?

[weederr33]

Originally Posted by NOMAD86

Car is already lightened with rear seat delete kit and some Sabelt seats. Don’t want to go full monkey cage and bare metal interior though.
Could maybe shed a little weight more but no substantial gains there, I think.

E85 is not available, but we do have 102 Octane 'race' fuel available, so could gain a little there.
I thought a further smaller pulley on the SC is not possible?
Bigger crank pulley sounds like an option...but how big and don’t you run into rollers and tensioners down there?

I believe you can make the pulley smaller, but it would need some adapter which could protrude a bit and hit the hood potentially. Matt@Cosworth talks about it a bit somewhere in this thread as well as on the UK thread.

It's a shame you guys don't have corn power (E85). :/ And yeah going crazy on all the bare metal is no fun. When I had my kit, it felt damn good at just 280 bhp. But that's all relative.

[botbs]

Originally Posted by nikitopo

In what gear are you doing the log?

3rd gear

[Seba]

Hi,

what device and software do you use to collect and save live data when driving the car?

Seb

[gtengr]

Originally Posted by Seba

Hi,

what device and software do you use to collect and save live data when driving the car?

Seb

I use ecutek and a laptop