G1en

So I decided to bite the bullet and bought the Redline Oil: I must say, only been out for a 15 minute drive today plus the initial drive back from garage but gears feel much smoother. So new 2nd and 4th Synchros fitted and the "right" oil in. I took it upto about 80 in 3rd (6k revs) and no issues into 4th so will wait now until new season with fingers crossed that its one less thing to worry about. 2nd was always stiff and now feels completely different as well. Obviously too early to recommend this oil over anything else but will update this next year IF it does the business. Who knew too slippy could be bad.

Found an old topic on the site where opie oils recommended just this Redline product So the Gearbox company may have a point, may need to get this?

As some will know, I do a fair bit of track/race stuff in my 350z and one of the big problems this year was 4th gear. Now the gearbox is being re-built for the second time and the company doing it local to me (Its all they do so they know gearboxes in general inside out) have thrown a big spanner in the gearbox so to speak. They rang me today to say the 2nd and 4th synchros i had provided to be swapped, that the existing synchros looked A-ok and only 5th (which i did not do last time) looks like it needs doing, well definately needs doing they said. now i don't have a new 5th synchro to put in and thats not important really as I never use 5th on track, but they also said they think my main issue is the oil i am using. Now I cant remember the last lot i put in, its probably on my build thread, I think it was Fuchs 75/90 titan stuff but that isn't really the point of this as I explained to him I change the gearbox oil twice a year anyhow and every time its something different but I try to get the "best" & "expensive" stuff i can find, This is the problem he explained, I am using oil with too low friction, its basically too slippy and not allowing the synchros to friction and bite! I am trying to understand why the more expensive an oil is, the more it offers "low" friction but the gearbox builder says this is bad and I should be using 10W40 engine oil or a cheap mineral oil (definately not synthetic) which kind of goes against what you would think, BUT does he have a point? does anyone know? Also, the second spanner in the box is that online (i know i know) lots of forums stating DO NOT USE GL5 in a 350z box only use GL4 with some rational behind it stating the GL5 contains additives that degrade the brass Synchros, now I have definately been using lots of oils that state GL4 & GL5 like the one i am about to put in now below: Like above, I thought as the box is being rebuilt again, I would opt for the best i could find, Motorsport use and states suitable for synchromesh gearboxes but is this going to cause more issues than it solves? Does anyone know if this is ok?, i am going to ring Millers tomorrow and ask their technical team. But would also like to know if anyone definetively knows whether a GL4 / GL5 combi oil is no good or a fully synthetic is no good or that we should be using a cheap engine oil / mineral oil for track use (slamming through the gears at high RPM) as they offer a better coefficient of friction required for the synchros then chip in. I may update this with future findings but no doubt the proof of the pudding will be when i do the first event of the season next year and how long it takes for me to swear at the gearbox!

Last event of the year for me and back to Curborough:

I have noticed an improvement in acceleration/gearing going from a 40 profile to a 35 profile rear tyre this year. essentially like dropping a cog on a pushbike so its easier for the drivetrain to turn, thats prob why he says going from a 19-18 inch wheel reaps more benefit than a 10 to 9kg wheel swap. you can improve the gearing by either a final drive swap, smaller wheels or lower profile tyres, it all does the same thing in essense. I am no expert but I think thats what he is getting at without going into the detail of confusing the viewer. Its also probably why lots of sprint/hillclimb cars (that i have seen) fit the smallest but widest wheels they can get away with to clear the brakes/arches. No doubt a lighter wheel is better and we should always opt for that if competing (and strength taken in to consideration) but your not going to be adding 50kg of multiplied weight to the car and adding 5 seconds to your laptime by going a kilo per wheel heavier like the internet would have you believe.

Yeah, it basically confirms what my thoughts were. The wheel weight makes a small difference but nowhere near the 4 times or 5 times unsprung weight multiplier banded about. he doesn't and no one seems to factor in that a lightweight wheel is 9kg say against a 12kg cast wheel but you also have 9kg of brake disc and 10kg of tyre plus rest of calipers and hubs so as a % overall weight reduction its negligible. basically lighter is better but not worth getting hung up about a few pounds/kilos as any non professional driver will not notice or care, buy the wheels you like.

Penultimate event of the season:

At the start of the year I fitted new discs and pads ready for the season. I went for Black Diamond (i think) slotted discs and PBS Comp Pads. I noticed after a few events hairline fractures/cracks in the discs but just ignored them as they didn't seem to get any worse. Well during this weekend at Blyton, they had developed from just a hairline crack to more like the grand canyon. You can see all the hairline ones i mentioned but I think you will agree it might not be advisable to be slamming on the anchors from 110mph to 30mph on track with these. The other side - pic below - crack wend all way through the disc! So with a full weekend at Curborough this weekend coming I thought i better not risk them, Tarmac Sportz to the rescue who only had Pagid "standard" discs in stock but with only today to fit them I couldn't wait to order anything so a trip to Derby in the morning and then got them fitted this afternoon. Thanks Chris. And while I was at Tarmac HQ, I picked up my diff brace I had ordered and fitted that as well, with the abuse I give the car, its a bit of extra reassurance the diff wont part ways with the subframe anytime soon. Video of Blyton to follow below, safe to say, I need a gearbox rebuild asap

Three Sisters 2 Lap Sprint Today

Back from full Weekend at Snetterton Great Sprint track on the inner 100 circuit. 4th gear not happy but new PB

Curborough Sprint from today, only 1 timed run ☹️

This Is Grassroots Motorsport at its most Grassroots Level with lots of Grass Unfortunately I went onto the Grass and hit the roots.... Scammonden Dam

Three Sisters Yesterday was good fun - get your mind out of the gutter people....

Loton Park Today - Glorious Weather

Back to Harewood this weekend .