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Discussion Starter #41
Ah, sorry. I get confused and lose track of what I have or haven't mentioned in each of the forums.
My plan was always for this to be the first car to be followed by a second better car. The only change to that plan is that I was originally going to keep both, but now I decided by retiring the first I can achieve the second one quicker.

I realised earlier this year that my ideas for the second car were all wrong. It was going to have a smaller motor and batteries, but I realised I need all the power of the existing motor and batteries. It was also going to be front wheel drive again. That decision was based on statistics for Motorkhana records showing most records as held by FWD. But I have since realised they are all ICE cars and I am giving up a substantial portion of my torque advantage through wheel spin being FWD. So I am now building a RWD so that under acceleration it will add grip to the driven wheels rather than reduce grip.

The new car will be 100KG lighter (if not even lighter). That represents about 20% weight reduction. It will be mid engined rear wheel drive. I will just take my existing motor/gearbox and mount it behind my seat. I will pay particular attention to my steering as that was a key weakness of the first car. And I will also pay attention to the rear suspension geometry and both roll centres as this was another key weakness of the first car. The new car will be a single seater and with no motor out in front I will be able to streamline the design/aero. It will have a perfectly flat underbody and will sit much lower to the ground. The new car will be about 160mm narrower which will allow quicker times through chicains and slaloms but won't be so much narrower as to compromise the rest of the handling. The batteries will sit on the passenger side of the car (if there was a passenger) and will be mounted as far forward as possible (up against the front firewall. This should keep the weight distribution fairly even although I am expecting the front to be noticably lighter than the back.

I am probably about 15% into the build. I am on track to be ready to retire the first car in November and transfer the key components into the new car. It should be running in Jan and competing in Feb.

Your assessment of that video is excellent. With more rear grip I would have been able to hold the corner speed and I think my times would have been around 1 second quicker (if not better). The terrible rear geometry plus inferior rear tyres were the cause there. You don't normally expect to have massive oversteer in a FWD car. Hitting the correct racing line was near impossible much of the time because I was struggling to hold any particular line. It really was that much of a handful. Plus there are a couple of particularly blind corners. You actually need to pick the entry for the corner perfectly and begin turning before you even see the corner. I need more track time there to really get the hang of it.

I will follow with some progress pics of the next car.

Thanks so much for the support.
 

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Discussion Starter #46
These are the latest photos of my new project car. It is progressing quite well but it is still touch and go whether it will be ready in time for the first event Feb 11.
 

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Discussion Starter #48
No, not just yet. I had some delays getting some custom steering components which have set my schedule back. I only just picked up the components. I am unsure if it will be working in time for the first event Feb 11. But I am going to give a it a good crack. I figure to stand any chance of being ready it needs to be driving by the end of this coming weekend. I have attached the latest pics which give a much better indication of how the finished product will look.


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Awsome! just to clarify a few points from page 1 the N13 was sold as a nissan sunny over here. i take it your using the gearbox from a CA18DE engine? the N14 was also named a sunny over here the N15 and N16 became known as an Almera then they have just released the Pulsar name here with the new C13 chassis based on the Tiida.

The Gearbox housing bolt pattern looks very similar to the SR20 one have you looked into an N15 VZR SR16VE gearbox? you can get a very nice Mfactory LSD for them aswell as a shorter final drive and they come with shorter ratios.
 

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Discussion Starter #51
The brakes have not yet been installed. I will provide some updated photos after this weekend.
Yes the Hydraulic handbrake will be installed this weekend too.
I will have some videos after the test drive....not sure when that will be though.

I have thought about a light weight body but really even a light weight body would still add weight to the total. It also wouldn't look right with the full cage. I am quite partial to the 60s sports car shapes like the Lotus 23.

The N13 here is the same body as the international N13 but the motor here was a locally manufactured GM product (Not the CA18). So I am not sure how the gearbox differs. I certainly have considered the later gearboxes. But I am trying to build the car based on components I already have and trying to keep the budget low. It is still on the cards but it is tricky as the width of the car is dictated by the drive shafts. So the drive shafts would need to be compatible which is tricky.
 

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Discussion Starter #53
Spot on. I missed the first event. I needed an extra few full days of effort to get the car finished. The good news is that the event on Feb 11 was only a test and tune and didn't count towards the season. The down side is I really really needed that test time to understand how the car drives. In particular any understeer.

The first true event is March 4th and unfortunately it is a higher speed event. So I am a bit nervous about driving an untested car. So I will need to ease into it, which will probably mean I won't achieve the points I would like.

As it stands today I just need to fill the brake lines, connect the end of the cable handbrake and connect the batteries/controller to have it running. Then there are a few minor finishing touches, like wheel alignments, before the next event.

The compactness is an important design feature as it allows better times through tight courses like slaloms. Ideally I would have liked it to be even more compact but I don't think it would be achieveable with the components I am using. I haven't got much spare space at all after mounting all my components. For the slower/tighter events I will run the same size wheels front and back. The reduced rear width will allow me to cut corners much tighter without hitting the flags. But for the higher/flowing events I will run my bigger wheels on the back which will make the rear width almost the same as the front and offer more stability through faster corners.

We have/had a similar category here called Aussie Racers.

The look of the car has improved a little since those photos but it is up on stands in my garage at the moment. I'll have it out in the yard for more photos this weekend.
 

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Discussion Starter #54
I got the car running last night. This is a huge releif as it means I am fairly certain of competing in the event this Sunday. I do still have a few things to do but they are fairly minor.

I also weighed the car (As best I can). The car came in at 480Kg with weight distribution of about 44/56 toward the back which isn't too bad.

The first drive felt very good. I think it has promise. I just need to do a wheel alignment, brake bleed and some minor additions to be ready for Sunday. I should have some good videos early next week.
 

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Discussion Starter #55
Well the event was good. But it did reinforce why a practice event would have been an advantage. The car understeers severely and the front brakes lock on anything more than a slight touch. I also blew a fuse part way through my first run.

I went for an extra run after the timing was finished for the day. It was oversteering as normal but then it suddenly gripped and snapped the back around unexpectedly. I over corrected and speared off into a culvert. It made for some gread video though.

I have some work ahead of me to somewhat neutralise the handling.

 

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Discussion Starter #56
I managed 24th place outight. On the surface that isn't too impressive. However that included my first run where my fuse had blown. If I just take that run out of the equation I would have placed 10th outright. So for it's first outing I am fairly happy with those results.

Now I just need to work on the brake bias and understeer to move my way up the standings toward the podium.
 

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Superb :)
It looks like the steering wheel isn`t turning true on the boss or could it be slightly bent even?
I am very impressed,keep up the good work/fun.
Very good result from the first outing too.
 

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Discussion Starter #58 (Edited)
Thanks. I wouldn't doubt the wheel could be bent. Particularly after that last run. I would suspect I braced myself for the impact against the wheel. I don't notice it while driving though. I do have a new wheel to go on. I guess I am just waiting until I get some of the bigger issues sorted out first.
 

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Discussion Starter #59
Just a quick update. During the first outing the new car demonstrated noticable understeer, front brake lockups, slow steering and slightly reduced launch speeds. All of these were expected at this stage in the development.
•The understeer and front brake lockups are due to the lack of weight over the front wheels.
•The reduced launch speed was because I have not yet installed a clutch pedal and master cylinder resulting in the need to launch in a higher gear.
•The slow steering is because I have not yet modified the steering to speed it up.

I can't do too much about the weight distribution, although I have added a second auxillary battery in the nose. This adds another 7kg to the front of the car.

This past wekend I altered the front suspension pivots to substantially soften the front. I added some more caster and some more negative camber to the front both of which should increase front grip during cornering.

I still need to:
•Reinforce the panels around the brake pedal to give a stiffer feel
•Add a brake bias adjustment to send more pressure to the back brakes and eliminate the front brake lockups
•Add a steering quickener to speed the steering rate
•Make and install a hydraulic clutch conversion
•Finish and install the replacement handbrake handle
•Make an adjustment to the ackerman angle

The first 5 of these modifications must be complete before my next event on April 15th. I will provide another update before then.
 

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Good stuff,take some thinner but more grippy tyres for the front with you to fight understeer.
I have found tyre compounds essential to get good set ups/feel for the day/track surface.
You have done very well to keep the weight down.
Watching with much interest,very best of luck.
 
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