Track S15

[Byah! 210]

man, went full circle on the brake setup! you gonna put in ducting for the fronts? Been meaning to do mine for months now but have not got round to it.

[volt_bite 140]

Nice work Mark. So running the Evo brembos on the front and R33 Gtst on the rears?

[datman55 16]

Nice work Mark. So running the Evo brembos on the front and R33 Gtst on the rears?

 

Yes That's right. Evo's still going on the front, Ready to get the dog bones made for those. Once they are done, all the brakes will be bolted up and I can start on the balance bar set-up, master cylinders & plumbing it all up.

[datman55 16]

It's been a couple of weeks since the last update, work has been keeping be occupied! Finally this afternoon, I found a couple of hours to get started on the rear R33 brake upgrade.

Getting the old calliper and rotor off was a little challenging after they had obviously been on there for the best part of 15 years. Once that was achieved, I cut back the guard/backing plate to the rotor (as the stock one fouled on the Skyline rotor). This backing plate will be completely removed when I change the rear upright. Once that was done, the rotor and calliper bolted straight up.

The end result is an upgrade in rotor size from 258mm (solid rotor) to a 297mm ventilated. Additionally the standard calliper was a single piston calliper, and the Skyline one is a twin piston calliper.

The entire hand brake assembly has been removed also.

 

[Byah! 210]

Lookin good Mark!

[datman55 16]

Slowly but surely.

[datman55 16]

Yet another change of plans this week. After it being suggested that the Pedal Ratio on the car may be no good to run un-boosted (Thanks Dalspec), I took some measurements and sure enough the pedal ratio is only around 4.1:1

This means I will have to shelve the balance bar set-up and run a full pedal box.

The research begins now on pedal boxes.........

[datman55 16]

So it's been a while since the last update, and it's been about 6-7 weeks since I have had time to even touch the car.

 

With the rules for Improved Production in limbo at the moment surrounding the use of Floor Mounted Pedal boxes, I have decided to run with the stock Booster and a larger master cylinder until the rules are finalised and I can decide on what type of pedal box to run. The current rules allow for a top mounted (or hung) pedal box, but the new rule will allow for floor mounted pedal boxes. Floor mount is certainly the preference, and will be much easier to fit to the car.

 

So now the list of things to do before the next track day looks like this.....

 

1. Fit bigger Master Cylinder

2. Buy & fit GKtech abs delete kit

3. Get front caliper adaptors made & fitted

4. Machine brake rotors

5. Buy new brake pads

6. Fill & bleed braking system

7. New wheels & tyres (Looking for R33 GTR wheels for the time being - will upgrade to Enkei rpF1's down the track)

8. Buy & fit baffled sump

9. Dyno tune to check engine tune is safe for track work.

 

Still plenty to do, hopefully I can find some time to get it all done sooner rather than later.

[datman55 16]

Everything seems to be going so slowly..... it's good to be busy with work, but it hurts the build time!

 

Anyway..... I should have the caliper brackets in the next couple of days, very excited about that. I'm hoping to have the front end all back together over the Christmas break, and then I'll just have to plumb up the brake lines, fit the master cylinder and bleed the brakes.

 

I have also continued the weight loss effort in the last week or so. I have started stripping the sound deadener out of the car, and have so far pulled 6kg's out, and I'm only about half way through. It leaves a horrid residue behind which I still need to attack with thinners and a heap of rags to get off, it doesn't look like it's going to be much fun. Once that's done, I'll also attack the Dynamat which has been stuck all over the boot. Should be quite a bit of weight there too. The rear wing has been removed also (that was 2.8kg's). I'll be looking at removing the door intrusion bars (car will be caged) - unless there is someone out there with Red S15 JDM doors that wants to swap? Other weight saving areas I'm looking at include swapping the mirrors for smaller lightweight race style ones & removing the SPEC-R factory bracing (once the car is caged). I'm chasing around 100kg's from the last weigh in, which will get me to 1,060kg's. From what I understand, the cage will weigh around 40kg's, so the car should come in at 1,100kg's plus driver...... that's the target at this stage.

 

Still a bit to do, but hopefully some time off over Christmas will help get through some of the list above.

 

For updates, see my Facebook page for the build up..... https://www.facebook.com/fullthrottlemotorsport

Edited December 20, 2016 by datman55

[volt_bite 140]

Why not use dry ice to remove the sound deadener? I think you can get it at BOC gas. I know orange oil works wonders too but probably not very cost effective.

 

Chromoly arms everywhere! That'll save weight too xD

[datman55 16]

I used dry ice to get some of it off, but it doesn't work on the sound deadener that is under the front seats or in the foot well.

 

I have to run standard arms in the car under IPRA rules, so no weight saving there either.........

[datman55 16]

On the issue of weight saving......

 

We know the S15 came in a few different specifications, mine is the Spec-R. The Spec-R received a few nice trim things (i believe), completely useless to a race car, but it did also receive some extra chassis bracing from the factory. I've been wondering two things....

1. Will this extra bracing be required when the car is caged (probably not - but maybe some of it)
2. How much does it weigh? (yes I am obsessed)

So tonight, I pulled each piece of bracing off the car and weighed it... here's what I found.

A) Boot brace - rear of boot = 1.9kg's (interestingly, when I unbolted it, you could see how much the brace was under tension. Probably due to the car sitting on car stands at the moment, and not on it's wheels (not sure if this will be needed when caged - but probably not)
B.) Boot corner braces (front of boot) = 1kg (wont be needed when caged)
C) B Pillar lower braces = 3.3kg's (wont be needed when caged)
D) Roof Brace - 1.8kg's (wont be needed when caged)
E) Front chassis brace (under car) = 1.5kg's (Probably not required when caged)

That's a total of 9.5kg's that can come out of the car!

There is also one more on the car which braces between where the rear cradle mounts to the chassis. I forgot about that one, but it looks like it will be just under 1kg (guessing based on others). (Not sure if that will be required when caged)

Next up is to look at the door trims, and possibly relocate the Power window switches to the centre of the dash so that I can do away with the standard door trim and replace with a sheet of carbon fibre. Will also make fitting the cage easier when the time comes. While the door trims are off, I can also tackle the removal of the side intrusion bars from the doors.

So much weight to take out, I feel like I've been to Jenny Craig!

 

On a side note, One of the things I was surprised about when I first got the car, was how stiff the chassis was when being jacked up from one side, it had very little flex. Almost like a fully caged race car. I believe, that part of that is down to the Spec-R chassis bracing. For a street car being used on track days etc, I believe it would make a difference for sure. On a caged race car, it's just extra weight.

Edited December 21, 2016 by datman55

[Byah! 210]

yeah thats pretty obsessive!!!! but if you are going to do it, guess its good to do it properly!!!

[datman55 16]

Trying to get the car down to 1,050 kg's before we stick the cage in it.

[kyle_340 527]

guess you need carbon fibre everything

[Byah! 210]

s15's like 12-1300kg?

 

that's a lot to drop if so...like I could easily identify 100-150kg in my head....that's bout it hahaha

[datman55 16]

It's amazing how all the little bits add up. We can't use lightweight body panels or glass. Not allowed to drill lots of holes etc either. It's certainly a challenge, but one I hope to win.

[datman55 16]

Picked up the dog bones today, and they look great. I have a little bit of work to do to the callipers to add some clearances in a couple of spots, plus I need to source some bolts to bolt it all together, but at least I've got what I need now and it will all work a treat!

[Dalspec 10]

Good job Mark. Look forward to seeing it all bolted up.

[datman55 16]

I got most of it bolted up as a Dummy Fit, and it's looking good. Ran into a small problem, which can be easily rectified. The top bolt for the calipers is directly in-line with the lower bolt of the strut, and there's not enough clearance for both. Luckily, there seems to be plenty of meat in the adapter at that point, so we should be able to recess the bolt enough to clear the strut bolt.

 

Pics will be up on Facebook soon.

[Ungodlyfreak 67]

Looking good!

Just curious, will you be doing much aero development on this car? I've been looking into aero for the wtac car i hope to build someday. It seems to be a very interesting "black art" as some people call it.

[datman55 16]

G'day Israel.

It will get some aero, but we are constrained by the IPRA rules to a degree.

A new wing with adjustable element will be made for the back. Front end will most likely see a different front bar with an under tray incorporated into it. Final option has not been decided upon, but looking at the Aero bar with an under tray fitted to it. I am allowed to run after market front & rear bars, as long as they don't protrude further than the stock ones when looking from above. This also means I can run Carbon Fibre, but not sure if I want to do that or not?

[Ungodlyfreak 67]

Ahh ok, cool. What about engine bay ducting, a rear Diffuser or front splitter? Are there any options for those? Sounds like you're fairly limited there though.

As for carbon parts, what are your options for getting those? Would you make them, buy premade or get something custom made up? I imagine it would be expensive any way you approached it.

[datman55 16]

Engine Bay ducting - Must run the standard bonnet

Rear diffuser - only if it's standard on that model

Front Splitter - This is ok, as long as it does not protrude past the bumper, and the bumper can not protrude any further than the original bumper when viewed from above. An under tray can also be fitted to the front bumper, but must be flat - no venturi.

 

The guys who made the Calliper adaptors also make carbon fibre parts. He would need a mould though, and I'm not sure how much it would cost. My other concern is flexibility & repairability. Without doubt, at some point, both the front & rear bars are likely to get "touched up" on track. Fibreglass id probably going to be a better option than CF in this respect.

[Ungodlyfreak 67]

Ahh ok. So your aero package is extremely limited. I'm looking into all of the above, trying to find the best options.

Not sure if i want to go to the extent of getting carbon parts. I think I'll leave that till last.