Tuning turbo time!

[fingers99]

Or what you put into it.

J333EVO has 15", recons they are better. I don't sometimes call him Ayrton for nothing!

Oddly enough, he's not using low profile. I'll be trying 15/195/45 which isn't radical at all.The point about blade types is that you can adjust them from within the cockpit -- and that the adjustment is theoretically infinite. It's what, 40 year old F1 technology, 25 year old in Touring Cars. Simple, basic engineering. An ARB can only be "right" with respect to a number of other factors -- circuit, track conditions, dampness, condition of tyres, etc.

 

[craigb244]

yeah... recons... im not the type of person who goes out and does something because someone i dont know "recons"

but people i do know and from all kinds of motorsport (not track day users)say that id be better of running 13s



with the arb yes sounds like simple engineering... i looked at them. but id be very impressed if you ever pull it off.

having something fully adjustable is usually not a good thing unless you have lots of practice time on a track and a team behind you... not something you get when sprinting or any sport ever done in a cento

its better/easier to learn how the car handles with the same setup in all conditions rather then tweak.
you will more then likely make the car handle worse and you will learn to compensate and have to relearn every time you tweak

same with coilovers/adjustable dampers best to just set them to what feels/knowen good and stick with it.

 

[Munkul]

I'd tend to agree with you Craig. Except an adjustable ARB is a VERY useful thing, and you can get relatively simple and cheap setups (Not in-car adjustable, though!) - just need to find someone with a bit of motivation to do it not me, I'm way too lazy!

Also, a blade ARB is one of those things where you go to a track day, adjust it for a few laps,adjust it again, etc etc. I've done this on the road with the geometry on the punto (played with camber and toe quite a lot) and also dampening and brake bias on my s14, not on track yet though.

But aye, on the whole, Fingers you tend to complicate things for no good reason. We're talking fiats, not formula 1, not even formula 3000....

 

[J333EVO]

I suppose as my name has been taken in vane I should point out I worked for Abarth UK last year in the Trofeo 500 series with the father in law (UK 1976 under 1600cc rally champion, chief mechanic Nissan Europe WRC, development engineer Tickford, Cosworth & Mahle) & Andy Dawson who those with knowledge from within motorsport needs no introduction, Nissan Europe team boss, Manx Rally winner Lancia Stratos, 555 Audi Quattro Asia team boss etc etc long term family friend. I've learned from some of the best, but don't pretend to know more than I do, lots of very knowledgeable people out there who have forgotten more than I know.

I use 15" at present as Toyo produce the 888 in 165/50 15 (as per Daihatsu Copen & other small Jap cars) as nothing really suits in 14" & 13" is too small for my brakes which for trackwork perform better as dissipate heat better. It gives much better steering feel & a better turn in than the previous 185/50 14.

I'm not saying a 13" can't work, but would either reduce gearing way too much for my car, or have much taller sidewalks were the only form of motorsport to effectively use the sidewall flex of the tyre as part of the suspension action is F1, a reason that Michelin said they would not return unless they switched to 18" wheels like LMS to reflect mote what is produced on the road.

Adjustable anti-roll bars are brilliant especially for different conditions, wet/damp soften it off, dry stiffen it up, same fir damping & even camber & toe should be adjusted. Or if you take tyre temps you can change toe to increase speed of tyres heating etc it's a black art that not many can perfect.

There's no right & wrong only an objective & a route to an outcome.

 

[craigb244]

well yes if your doing a lot of laps but sprints are usually 4 runs and that's all. not enough to tweek.

making my arb adjustable is simple. change my normal rubber bushes drop links to rose joints (I don't have any big enough) and drill extra holes in the lever on the arm (already done that) which simply changes the tention. but like you I'm to lazy. my rear arb works brilliantly and ill leave it at that.

 

[craigb244]

J333EVO, sorry if you took my comment personally or it seemed offensive.
just trying to say that because one person says somthing worked don't mean everyone should go and do it without a second thought.
and that if someone seemed better don't meen it is or is optimal.
how many boy racers fit ultra low stiff suspension. fit an induction kit and say the car is much better handling and a lot quicker when most the time its not and can have infact the oposite effect.

as for tyre walls I think it depends. my mate is a VERY skilled autotest driver. he recently started doing it in a panda 100HP (used a mk2 8v 1.2 punto before) and was having a lot of trouble. he was then told to fit smaller wheels with higher profile tyre (overall the wheel is the same size) since doing that he's yet to be beat and says the car is MUCH better

 

[J333EVO]

Not at all Craig, what works for one discipline does not neccessary work for another, & in fact it's the young guys like you in grass roots Motorsport who learn, develop & grow in experience who are the guys in the future the youngsters look to.

Suspension as said is a black art, even the dampers Andy is building for an historic Nissan 240RS rally car are all individually dyno'd, springs rates developed to suit the vastly different pick up points from OEM to ensure minimum or no bump steer. When you see true engineers like these guys really opens your eyes to how much work has to go in to make sometimes the smallest but biggest impact changes.

Cinqs are simple & agree there's no need to overcomplicate things.

 

[ycming]

Am in trouble here, i run no ARB and 13" wheels in auto-test!

Ming

 

[fingers99]

Am in trouble here, i run no ARB and 13" wheels in auto-test!

Probably not. If you think about it, no front ARB is half a step to running a rear ARB.

But you can't adjust for skew, diagonal roll. For a fair bit of competition stuff (but not for road stuff) suitable tyres are only available in 13".

And auto-test is really, really specialised stuff, where you'd expect a lot of road/race/rally logic to fly out of the window.

 

[fingers99]

yeah... recons... im not the type of person who goes out and does something because someone i dont know "recons"

Actually I got the 15" tyres and wheels long before J333EVO did, (see the pics in my gallery) in response to the dreaded Cento tub torque steer/boost spike issue. I recon I can tune a suspension to eradicate the extra unsprung weight.

 

[Whiley]

I found wider wheels actually helped with torque steer/putting power down tbh, would love to go out in one of your cars with a rear arb to see how different the handling is tho definately and would love to see any pics anyones got as its something id be looking into when i eventually decide to buy another cento.

gaz

 

[craigb244]

i uploaded photos a while back. i might take some more of under the car when i get it on the lift to do the tracking

 

[blu73]

theres some good pics of Aarons in his build thread.. modified MGF front arb iirc - looks very pretty and i want one! lol

Your thread could do with an update Aaron

 

[craigb244]

think you mean rear mgf arb...



updates a bit slow cos ive been busy working.
ive ground out the ports on the flange and got one of the guys to tig the center of the pistons. they look great and now back to the original thickness (he reckoned they would be strong enough as it was anyway.)

the collector is just waiting to be welded on

 

[fingers99]

You welded up the pistons?

 

[craigb244]

i mentioned it a couple of weeks back. tested on scrap pistons (16 and 8) cut and checked.
was going to use strips of scrap piston but we found out what they are actually made from and used matching filler.

 

[blu73]

think you mean rear mgf arb...

I'm pretty sure it was a front arb - they not as bulky/stiff being that mgf are mid-engined. I maybe wrong but sure i read that a front arb from a mid-engined car is better suited due to there being little weight over them. But i may remember wrong, my memory isn't my strong point lol.

 

[craigb244]

I checked after.

even aaron said front arb but it is infact the rear arb.

the front is nothing like the rear arb (front actually looks very similar to the centos front arb iirc)

 

[blu73]

so remembered right then at least

 

[craigb244]

progress