GW 200 CUP (clubsport->racecar->v2)

[burrellbloke]

Can you not just take out the passenger side light and put in a blank/cold air feed rather than use a smaller duct?

Also, don’t forget that every time you look at the photo of you on Paddock Hill bend I will be looking back at you!

 

[LiamP]

I decided this was the cheap/quick option but might go down the air feed through the light if this works, not a fan of no lights though tbh.

Yep, I was going to photoshop you both out

 

[RSRowe]

If it settles your mind a little, I ran mine with the low battery warning for about 2 years until it finally stopped doing alternator things.
As for your airbox vent. A cheap way of doing it is spinning the bottom section of the airbox round 180° so the inlet sits towards your vent. It does look a bit crap though with the mounting lugs sticking up.

 

[LiamP]

I will force myself to test all three next time I am out, no feed, feed and upside down. My only concern is the heat from the rad as I imagine it’s pointing directly at/above it.

 

[EthanMenace]

I decided this was the cheap/quick option but might go down the air feed through the light if this works, not a fan of no lights though tbh.

Yep, I was going to photoshop you both out

we have ruined what would have been a very clean photo

 

[LiamP]

Last minute booking at Snetterton with MSV last Thursday, decided the drive was worth the £200 saving over Brands and I needed some practice. Pleasant surprise to bump into @Helpimonfire as I was pulling the car off the trailer.

I think it was about 90% race cars who all had the same idea including what seemed like half the hot hatch grid. Not sure we can be blamed when testing is double the price and you get a lot less track time.



Started the day off with dunlops and RPX to bed in, was having weird battery issues (usual theme) so changed the regulator to try and isolate it as I waited for the brakes to cool. Next session and the car started to develop a slight misfire during acceleration, double checked all wiring and fault codes but nothing showed.



Went out for another session and the car completely died on pit exit, it then came back alive, I realised at the point that it must be power related to the ECU. Somehow limped it back to the pits at about 30MPH without causing a red. After checking earths / power I opened up the UPC box to find the ECU connector not fully pushed in, facepalm as I had removed this last week when changing a buzzing relay.

I could finally started pushing the car and tbh wasn’t very happy, the RPX don’t have the same bite as ds1.11. However the big issues is the way they trigger the front ABS when trailing, it’s as if they continue to try and bite on the disk right when you want the car settled. The Dunlop’s were not that impressive either although admittedly I was running old rears on the front (backwards) which Martin told me others have said is not great.

Over lunch I switched the pads back to the old ds1.11 and the car felt considerably better even with how worn they are. To be fair to the RPX for the price they are a good pad although not for ABS / you get what you pay for.



I tried switching the air box around and looking at the data it doesn’t look like it has made any difference however I think this is because the temp sensor is just recording the temp of the manifold.

A few reds in the afternoon slowed the day down before I put the AO52’s back on and immediately started pushing faster times. Stiffened the front and rear up a few clicks and finally got the car moving again, I guess it makes sense that a grippier tyre requires a stiffer car.



Had a great final session with a few of the hot hatch grid, probably the most fun I have had in the car this year, really enjoyed having space on the track compared to Brands.





Reviewing the data I am currently a few seconds off where I want to be so started looking at others videos to see where I am losing time. One thing I have started doing is using iMovie to step through my lap against others. It’s not perfect but you can graph a rough delta corner by corner by just comparing a time stamp / location (corner exit curb).

Here I have compared Mike Epps lap and current lap record from Matt (insane time / lap) I had assumed I was losing time in the slow corners but it’s actually the fast corners (1/3) and the final part of the lap. You can see I actually gain a fair chunk in the mid section and I am only 5 tenths off by the back straight before bleeding time through Brundle/Bomb/Coram.



Going into more depth I am actually braking later but this is costing me, Matt brakes earlier, gets the car loaded up / settled and is then on full throttle before and through the apex. This is something I need to work on, struggle to have the confidence on the throttle through a corner.

Goodwood on Thursday with my Dad which is likely to be some fun / testing a few things and then racing Saturday with what seems like some good weather although it keeps changing.

 

[R20BTG]

This is something I need to work on, struggle to have the confidence on the throttle through a corner

This is entirely understandable given the shunt you had in the white shell

 

[av4625]

Last minute booking at Snetterton with MSV last Thursday, decided the drive was worth the £200 saving over Brands and I needed some practice. Pleasant surprise to bump into @Helpimonfire as I was pulling the car off the trailer.

I think it was about 90% race cars who all had the same idea including what seemed like half the hot hatch grid. Not sure we can be blamed when testing is double the price and you get a lot less track time.

View attachment 157773

Started the day off with dunlops and RPX to bed in, was having weird battery issues (usual theme) so changed the regulator to try and isolate it as I waited for the brakes to cool. Next session and the car started to develop a slight misfire during acceleration, double checked all wiring and fault codes but nothing showed.

View attachment 157774

Went out for another session and the car completely died on pit exit, it then came back alive, I realised at the point that it must be power related to the ECU. Somehow limped it back to the pits at about 30MPH without causing a red. After checking earths / power I opened up the UPC box to find the ECU connector not fully pushed in, facepalm as I had removed this last week when changing a buzzing relay.

I could finally started pushing the car and tbh wasn’t very happy, the RPX don’t have the same bite as ds1.11. However the big issues is the way they trigger the front ABS when trailing, it’s as if they continue to try and bite on the disk right when you want the car settled. The Dunlop’s were not that impressive either although admittedly I was running old rears on the front (backwards) which Martin told me others have said is not great.

Over lunch I switched the pads back to the old ds1.11 and the car felt considerably better even with how worn they are. To be fair to the RPX for the price they are a good pad although not for ABS / you get what you pay for.

View attachment 157777

I tried switching the air box around and looking at the data it doesn’t look like it has made any difference however I think this is because the temp sensor is just recording the temp of the manifold.

A few reds in the afternoon slowed the day down before I put the AO52’s back on and immediately started pushing faster times. Stiffened the front and rear up a few clicks and finally got the car moving again, I guess it makes sense that a grippier tyre requires a stiffer car.

View attachment 157775

Had a great final session with a few of the hot hatch grid, probably the most fun I have had in the car this year, really enjoyed having space on the track compared to Brands.

View attachment 157776



Reviewing the data I am currently a few seconds off where I want to be so started looking at others videos to see where I am losing time. One thing I have started doing is using iMovie to step through my lap against others. It’s not perfect but you can graph a rough delta corner by corner by just comparing a time stamp / location (corner exit curb).

Here I have compared Mike Epps lap and current lap record from Matt (insane time / lap) I had assumed I was losing time in the slow corners but it’s actually the fast corners (1/3) and the final part of the lap. You can see I actually gain a fair chunk in the mid section and I am only 5 tenths off by the back straight before bleeding time through Brundle/Bomb/Coram.

View attachment 157778

Going into more depth I am actually braking later but this is costing me, Matt brakes earlier, gets the car loaded up / settled and is then on full throttle before and through the apex. This is something I need to work on, struggle to have the confidence on the throttle through a corner.

Goodwood on Thursday with my Dad which is likely to be some fun / testing a few things and then racing Saturday with what seems like some good weather although it keeps changing.

What you say here about RPX pads is very interesting. I have them in my M3 and thought they were very good for the price but I have at times suffered ABS issues. I wonder is it the pads!

The way you say about getting slowed up and on the throttle early, I found that really worked in the Clio especially if you have a good diff. You could be quite aggressive with a well setup clio. I have also found it doesn’t work as well in the M3 (unless sideways is the goal) and I’m trying to break the habit of it and get better at trail braking in.

 

[LiamP]

This is entirely understandable given the shunt you had in the white shell

Agreed, I think seat time is the answer.

What you say here about RPX pads is very interesting. I have them in my M3 and thought they were very good for the price but I have at times suffered ABS issues. I wonder is it the pads!

The way you say about getting slowed up and on the throttle early, I found that really worked in the Clio especially if you have a good diff. You could be quite aggressive with a well setup clio. I have also found it doesn’t work as well in the M3 (unless sideways is the goal) and I’m trying to break the habit of it and get better at trail braking in.

In my case it was 100% the pads as the issue went when I switched back.

Yeah clios do like an aggressive driver, braking late / over braking and the momentum just dies.

 

[LiamP]

Finally bolted on the splitter I have been working on for a while, car looked awesome.





Fell off on lap 1, luckily just one side so was able to get back to the pits with the smell of burning ply.



I severely underestimated the amount of downforce it would create having bolted it to the weeder rad mount. This has bent the mount and then pulled the spot welds apart! Version 2 might have a few splitter rods involved.

After that the day was great, started really pushing the car again and was getting loads of confidence in the high speed corners. The car is about 1.5s faster than last time I was here but I think that might be driver / setup as I am actually losing 4/5 tenths per straight due to lack of top speed. This could potentially be drag from the rear wing, certainly something I need to test as I am not convinced it is worth it.

Managed to get the car/trailer on my drive for an early start tomorrow.

 

[R20BTG]

Looks quick! Sounds good too. What exhaust are you running again?
Love the little smack on the steering wheel at the end, was that in frustration or celebration?

 

[R20BTG]

I see you blanked off the brake cooling, is that because Goodwood is a bit faster without as many braking zones?

 

[LiamP]

Looks quick! Sounds good too. What exhaust are you running again?
Love the little smack on the steering wheel at the end, was that in frustration or celebration?

Its pure manifold attached to an Akra with a 200 cell cat welded in between.

The smack was annoyance for having to lift slightly on the exit as I went in a bit too hot

I see you blanked off the brake cooling, is that because Goodwood is a bit faster without as many braking zones?

Ah no, I was bedding in some new DS1.11 which I forgot to mention.

 

[LiamP]

Snetterton Round 6/7

Left the house at 4:30 to find myself talking to the police 5 minutes later when I came across a 4 year old in the next village on the pavement in her pj’s in the rain/dark, somehow had escaped from her house and was very confused / scared. This obviously delayed me so arrived 5 minutes before scrutineering with a very very busy paddock, took the easy option and parked on the grass about a million miles from the paddock.

Got through scrutineering without any issues which they always seem annoyed about. 30 minutes later called for qualifying in a relatively quiet grid size of 23 cars with 5 in class B.



Back on the AO52’s and the car felt good, was struggling with front roll in the mid corner but it was workable. The track felt slow and it was the general consensus in the paddock that the new tarmac is slower along with mixed conditions meant it was hard work to try and get the car turned in.

Set a 2:16.8 early on and then improved to 2:16.3 before my final lap was ruined by coolant/oil on Oggies which was scary. Was frustrated as it would have been a low 15 but was pleased to be able to get straight onto fast laps as it’s something I have struggled with. This got me pole by 1s ahead of an FN2 that had joined from Roadsports series, Dave (BH civic winner on the left) has moved up a class so the competition was less compared to previous rounds.



Q: P1 Class 2:16.341

Gave the car a check over and bumped front dampers up one click and rears by two clicks to try and remove the roll and get the rears working. I also changed the regulator as I could see the voltage drop below 13v when waiting in assembly area which scared the shit out of me.

Race 1

Delayed start as the FN2 snapped a driveshaft during the green flag lap, the marshals were a bit slow to realise and they almost started the race.

After another green flag lap I got a poor start meaning I was in amongst the Class C BMW’s which are silly fast off the line, got squeezed and took a hit on both alloys into T1. Very cautiously approached the following corners as I confirmed nothing was broken but things felt good. Overtook out of Nelson after being neck and neck down the back straight which is concerning considering he is supposed to be the class below. Got a good gap before a SC due to a C1 on fire on the back straight, race finished behind SC.







P1 Class 2:17.361 (FL)

Got to watch some racing in-between including the Roadsports race which was just awesome to see the grid, the quality of the cars is ridiculous. Darkside TT’s / TCR / motorsport spec M2 CS etc. strongly recommend going to watch if you like seeing very expensive race cars.

Race 2

Got a great start and was with the class A’s into T1, this didn’t stop Josh in the BMW going for a mega dive on the inside, he apologised and his excuse was ‘I forgot to brake’. Kept onto the back of the Class A train and started pushing the KA before my coolant and oil temp started rising. The oil then got to 120 deg before I let off to try and cool it down, slowed to 2m20s laps and the temp dropped down to 107. Luckily I had a decent gap so I could afford to not blow the engine and keep the position but was frustrated as I knew I could get a 2:14 lap with the optimal confirming. I am assuming the temp was due to the thermostat although testing on Sunday and it opened when idling so not 100% sure what caused it as I can’t see any leaks or anything obvious.





P1 Class 2:15.952 (FL)

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Fastest lap from R2, very scrappy and plenty on the table for next time.

Overall really happy with the day, confidence back up, car is super fast and I really enjoyed it.



Next race would be Silverstone Int in August but it’s Sat/Sun and I have been offered a seat to race with my Dad in the 2CV 24hr race the following weekend which I am going to do instead. The next race after that isn’t until September at Oulton Park which is a track I really want to do. Few things to fix and improve including splitter v2 which will keep me busy and probably a track day to test.

 

[LiamP]

Priority since Snett has been to improve cooling, having confirmed thermostat was working and no leaks the general consensus on insta was that my radiator was past its best. Easy fix with a replacement from frogjam.





I then got carried away and made some ali ducting to go around the radiator, likely to be overkill but it looks good.



Downforce

The next stage was splitter v2, I had been very lazy on how I attached it as well as assuming that the rad mount could take the force. It obviously wasn’t as it bent the mount and pulled the spot welds apart, new mount ordered from wheeler which has a slightly different (stronger) design with proper welds.



I know a few off the shelf splitters use spacers and share the bolt from the rad mount but I wanted something adjustable so designed something similar but using Ali right / T angle. This allows about 30mm adjustment whilst helpfully being strong enough to withstand 80kg? of downforce.







I currently have it set at 65mm at its lowest which gives should be a good balance between downforce and usability, regs state a minimum of 50mm at its lowest.





Drag Reduction

A few pages back I blamed my lack of top speed on the clutch but I am now thinking its actually just drag, from both the front and rear. For some context I am losing about 6 tenths+ at Goodwood just from the two straights vs the white car. First focus was on trying to remove the holes/gaps in the front bumper to further direct air to the radiator and increase the pressure at the front.





The current project is the rear, I have removed the rear wing and making a very rudimentary rear spoiler with the aim of cleaning up the airflow at the hatch. Although it looks like it will just remove drag it should also remove rear lift and help the splitter/diffuser work better as the current wing is in the worst place possible as the air becomes turbulent when leaving the hatch.









This video was the inspiration:

I have managed to convince the wife to let me race next weekend at Silverstone although just on the Sunday, so will be testing all of this in Club Enduro practice before racing from the back in HotHatch 30 minutes later...

 

[Zuban]

interested in your results with that style of drag wing. this was my preferred style of wing from the CFD I did a while back, does depend what your trying to achieve though.

If my memory is correct, then it will certainly reduce drag, it will also decrease the effect of the diffuser if you use one which is something to consider, I'd need to look back at the data, but have a feeling that a low drag wing went a fair way to negating the effect of the diffuser, which is small anyway, and is the reason my Clio no longer carries the 10kg of Diffuser and mounting kit. but my use case is different to yours. I'd need to revisit the data and maybe do some fresh run's to confirm.

Closing up the front to a minimum is a good idea Imo, I've done similar, and have gone from an uncomfortably light feeling front end at speed to a planted front end with only a minimal splitter.

 

[LiamP]

Awesome, what are you using? I started setting up openfoam but soon realised it was going to take a long time to get something working so have parked it for now.

I would be interested in the data, my understanding is that cleaning the air at the rear would help the diffuser but maybe not. As well as reducing drag I am after a more planted front end so looking forward to testing it.

 

[Zuban]

Yeah I use openfoam, easiest thing to do is take a copy of the motorbike tutorial and alter things like the frontal area and centre, speed etc, then swap out the geometry for your own. I don’t have a machine setup to run it currently but should have a backup of either the files or the Ubuntu machine I used if it would be useful. Not going to produce super accurate figures but will allow you to see the effect of different changes pretty well.

 

[Zuban]

have a bit more time to reply so I looked back at the last set of runs I did that led me to remove the diffuser. I've posted previously on this forum about how the diffuser does work, and you can show it, but the effect is small because the diffuser volume is small, and being so small, the 197 diffuser may be slightly better but no great amount, external factors can soon overtake it such as the type or rear wing or spoiler.

The airflow of the diffuser and the airflow above it is an important interaction from what I can see, on race cars, that can have large diffuser volumes, and aggressive wings, they work in tandem to create downforce, for our Clio's the interaction is between the air flowing through the diffuser, and the air flowing over the roof. The area behind the car is low velocity high pressure air, and the plan is the diffuser will speed airflow going under the car into that high pressure zone, an aggressive wing will help because it will be pulling air up out of that high pressure zone, lowering the pressure and increasing diffuser efficiency.

A drag style wing will effectively extend that high pressure zone behind the car, and therefore reducing the efficiency of the diffuser, albeit reducing drag because its extending the low pressure high speed airflow over the top of the car.

Here is the numbers from my last set of runs, my focus is for sprints with max speed in the 80-100mph area, so I prioritise weight over aero, but its still relevant. Ignore the Cd figure that will change a lot with resolution etc but differences in value are valid, what I took from the results was opening up the rear bumper to let air out was worth more than having the diffuser. And using a mix of drag wing ( more or less what your making ) or race wing (more or less what you had), you can change the balance between the aerodynamic centre, drag, and how much lift/downforce the rear generates.

The video that was linked, did not cover diffusers, but did note how an area cut-out of the rear bumper did improve things.

My conclusion was that unless I specifically needed some rear downforce, which I don't as I needed more front end stability, that a drag style wing with no diffuser was the best combination. I don't have a set of results run under the same parameters as the rest for a Race wing with diffuser, I do have a backup of the parameters so that's something I could do if it was of interest to others.



Baseline :

forceCoeffs forces write:
Cm = -0.125014
Cd = 0.263471
Cl = 0.0101454
Cl(f) = -0.119941
Cl(r) = 0.130087


No Diffuser :

forceCoeffs forces write:
Cm = -0.0418755
Cd = 0.247334
Cl = 0.0374798
Cl(f) = -0.0231356
Cl(r) = 0.0606154


Drag wing No Diffuser :

forceCoeffs forces write:
Cm = -0.01468
Cd = 0.236635
Cl = -0.0569357
Cl(f) = -0.0431478
Cl(r) = -0.0137878


Drag wing with flick no Diffuser :

forceCoeffs forces write:
Cm = 0.00866701
Cd = 0.265121
Cl = -0.10355
Cl(f) = -0.043108
Cl(r) = -0.0604421


Race wing no diffuser :

forceCoeffs forces write:
Cm = -0.0317931
Cd = 0.256511
Cl = -0.0644121
Cl(f) = -0.0639991
Cl(r) = -0.00041293

 

[LiamP]

Really interesting, thanks for sharing!

It’s pretty much what I expected in terms of reduction in drag / lift, the ~10% reduction in drag and a reasonable drop in lift at the rear although I see what you are saying regarding the diffuser.

Have you experimented in using these numbers in a program like OptimumLap?