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Skinners Sprint Micra

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Skinner_87

Skinner_87

Club Member
Putting the new bearings in the gearbox tonight and spotted something with the diff:

Gripper LSD Micra Race spec says 40/60 on the box re ramp angles but looking at the side of the diff I can see 40 on one side and 30 on the other.

Am I missing something or is it possible the wrong ramps are in there?
 

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Antony

Ex. Club Member
Silly question paul....

Is there any good reason why i cant do a reverse flow cylinder head on the cga3?

Mich like the old janspeed btcc primera.

So you can run throttle bodies with long runners out the bonnet without removing the brake booster and a straight enough exhaust routing out the back?

I know the exhaust valves would need to be increased in size and hardened (two lots of exhaust valves?) Also cams would be 180deg out... and lots of porting required. But i really cant see a downside.

Can you?

Sent from my SM-G920F using Tapatalk
 

pollyp

Club Member
Putting the new bearings in the gearbox tonight and spotted something with the diff:

Gripper LSD Micra Race spec says 40/60 on the box re ramp angles but looking at the side of the diff I can see 40 on one side and 30 on the other.

Am I missing something or is it possible the wrong ramps are in there?
someone mis-labelled the box? so that's 30deg acc / 40deg dec (angle relative to the direction of rotation. lower the angle, more wedging ramp force acting on the LSD clutch stack, more locking force per torque input)
perhaps verify details with gripper?
 
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Skinner_87

Skinner_87

Club Member
someone mis-labelled the box? so that's 30deg acc / 40deg dec (angle relative to the direction of rotation. lower the angle, more wedging ramp force acting on the LSD clutch stack, more locking force per torque input)
perhaps verify details with gripper?
Yep all sorted with Gripper before it went in Paul :) Im very happy with the diff but no power steering an Manx Roads makes for an interesting drive!
 
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Skinner_87

Skinner_87

Club Member
Silly question paul....

Is there any good reason why i cant do a reverse flow cylinder head on the cga3?

Mich like the old janspeed btcc primera.

So you can run throttle bodies with long runners out the bonnet without removing the brake booster and a straight enough exhaust routing out the back?

I know the exhaust valves would need to be increased in size and hardened (two lots of exhaust valves?) Also cams would be 180deg out... and lots of porting required. But i really cant see a downside.

Can you?

Sent from my SM-G920F using Tapatalk
That is way above me engineering ability or knowledge TBH Anthony but interesting though!
 
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Skinner_87

Skinner_87

Club Member
You ready for the Sprint this week Paul? Am looking forward to my IoM visit this week.
Nearly prepped Matt.

New suspensions on im just playing with damping rates at the moment & tyre pressures. R888R's 185/60/14 are scrubbing in well & im impressed with the grip.

The LSD is taking some getting used to :) its a bit of a hand full.

I've hired a HANS device as well so im keen to see how that fits and get ready for scrut on Wed night or Thurs Morning
 
Silly question paul....

Is there any good reason why i cant do a reverse flow cylinder head on the cga3?

Mich like the old janspeed btcc primera.

So you can run throttle bodies with long runners out the bonnet without removing the brake booster and a straight enough exhaust routing out the back?

I know the exhaust valves would need to be increased in size and hardened (two lots of exhaust valves?) Also cams would be 180deg out... and lots of porting required. But i really cant see a downside.

Can you?

Sent from my SM-G920F using Tapatalk
Interesting idea

I can't see why it wouldn't work, you'd have to swap the cams over and do a fair bit of porting. You would probably have to run a Standalone ECU and either ditch the cam sensor or relocate it.
 

Antony

Ex. Club Member
If im going to the trouble of maching the head to take 300deg cams and bigger valves.....why not eh?

It will be stand alone with throttle bodies.

Sent from my SM-G920F using Tapatalk
 

frank

Club Member
you would have to rephase the cams eh, turn 1 about 120deg clockwise and the other 120deg anticlock, i doubt if you would have room for 4 inlet valves tho
 

pollyp

Club Member
Yep all sorted with Gripper before it went in Paul :) Im very happy with the diff but no power steering an Manx Roads makes for an interesting drive!
lol I bet with no PAS the diff now tries to rip the steering wheel off ur hands exiting junctions/corners.
 

Low Rider

Poindexter
Moderator
Club Member
lol I bet with no PAS the diff now tries to rip the steering wheel off ur hands exiting junctions/corners.
They're arm breakers without PAS. I very much like the AP Suretrac in comparison. It's essentially invisible until you're under power.
 
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Skinner_87

Skinner_87

Club Member
They're arm breakers without PAS. I very much like the AP Suretrac in comparison. It's essentially invisible until you're under power.
I imagine the PAS will be going back on at some point Dave. I kept the rack & system from a spare car i broke last year just incase this sort of situation arose.

Either that or il have to mann up :)
 
Which alternator are you using? Suzuki swift ones are nice and small and light, I'm running one in my mini conversion and it's working fine so far.

There are various mounting arrangements so it may be possible to mount it using your new bracketry.
 
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Skinner_87

Skinner_87

Club Member
Which alternator are you using? Suzuki swift ones are nice and small and light, I'm running one in my mini conversion and it's working fine so far.

There are various mounting arrangements so it may be possible to mount it using your new bracketry.
It's not something I'd looked at to be honest, iv not weighed the factory one but they are weighty!
 
To be honest niether have I but the suzuki one is much smaller and in your hand it feels like it weighs a lot less, Brise make a light weight alternator that looks like a suzuki item.
I'll get you a weight for both as I have them both here somewhere.
 
To be honest niether have I but the suzuki one is much smaller and in your hand it feels like it weighs a lot less, Brise make a light weight alternator that looks like a suzuki item.
I'll get you a weight for both as I have them both here somewhere.
4.7kg for the micra alternator and 3.3 for the suzuki alternator if I remember rightly the suzuki one puts out less but it's running fine in my micra engined mini.
 
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Skinner_87

Skinner_87

Club Member
It's been a good while since iv updated anything on here. Not much to report really, winter rebuild ahead and a lot of body bracing and welding vs cutting out the none structural parts.

Alloy rad to go in as well....

Engine wise I'm still undecided
 

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Skinner_87

Skinner_87

Club Member
Bit of research and chat today about specing the car up. It's been untouched really bar the suspension and diff.

72.12mm bore forged pistons and rods to go into the CGA3 block.

A slight skin on the head as the bloc has 20thou removed already.

Aiming for 12.3:1 compression ratio.

An updated pump is sat in the garage and the injectors will go for a clean and test.

Also looking at options for a 200mm clutch or a beefier 180mm.

Engine to come out this month to be machines for the above. I can set to port matching the inlet mani to the head as well as that is standard shape at the moment.

Lots to do but I'm sure April will come around quickly
 

Low Rider

Poindexter
Moderator
Club Member
Very similar sized rad to what I'm using Paul. Ignore the slight angle, it was a WIP shot. Twin fans drop temps down much more efficiently and free up a good deal of extra room at the front of the bay for work in.

20160917_120115.jpg


Will be interesting to see how much machining work is needed on the pistons. Design may have changed since I last looked but there's some additional meat on the crowns for setting the comp ratio.
 

pollyp

Club Member
adding from my exp with high engine output,
the 180mm clutch had limited capacity and durability.
although my 200mm helix clutch can definately handle the torque reliably with durability, the PP is very!! heavy and long throw, which means the cable wears out faster and requires frequent oiling and maybe reinforcements.
another option would be like sirchris's multiplate clutches?
 

Low Rider

Poindexter
Moderator
Club Member
A single plate is more than enough.

Your typical 184mm Helix/Tilton unit with a run of the mill 300kg cover will handle ~160lb/ft on an organic plate.

My 200mm Helix has a 335kg cover and is fine on a cable. Should have tried yours at JAE Paul...
 
adding from my exp with high engine output,
the 180mm clutch had limited capacity and durability.
although my 200mm helix clutch can definately handle the torque reliably with durability, the PP is very!! heavy and long throw, which means the cable wears out faster and requires frequent oiling and maybe reinforcements.
another option would be like sirchris's multiplate clutches?
Convert to hydraulic might be an option?
 

pollyp

Club Member
Your clutch is crazy!
One press and I had cramp in my leg haha
lol tis a good work out driving it daily. just about the only sort of exercise I get these days :D

when I used to have the helix paddle clutch yrs ago and the cable was really sticking (this was before I found out about oiling the cable) the pedal was twice as heavy to push down so you can imagine how my leg was shaking during a long traffic jam going home (I almost couldn't drive it) and how the cable rivet eventually sheared off.
 
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Skinner_87

Skinner_87

Club Member
Very similar sized rad to what I'm using Paul. Ignore the slight angle, it was a WIP shot. Twin fans drop temps down much more efficiently and free up a good deal of extra room at the front of the bay for work in.

View attachment 51496

Will be interesting to see how much machining work is needed on the pistons. Design may have changed since I last looked but there's some additional meat on the crowns for setting the comp ratio.
One thing I have noticed Dave is that the fans on my rad are on the bumper side so I imagine they push hot air back into the bay? I need to power one up to test
 

Antony

Ex. Club Member
As the cga3 box is used in other nissans with hydro clutches. It shouldnt be that much of an issue.

Chris gets round the heavy pedal with an extended arm. Youd need to lengthen the lever on the pedal too to make the throw manageable.

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Low Rider

Poindexter
Moderator
Club Member
As the cga3 box is used in other nissans with hydro clutches. It shouldnt be that much of an issue.

Chris gets round the heavy pedal with an extended arm. Youd need to lengthen the lever on the pedal too to make the throw manageable.

Sent from my SM-G920F using Tapatalk
Stock clutch, stock cable, 335kg clutch cover = fine

Modern cars are turning people soft :p
 
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Skinner_87

Skinner_87

Club Member
Jesus iv not updated this or really touched the car in 5 month.

There's spacers and brakes to go on but it will be a press for time before April!

Porting the inlet mani / injector clean to do as well. A week of work should help :)
 

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pollyp

Club Member
A single plate is more than enough.

Your typical 184mm Helix/Tilton unit with a run of the mill 300kg cover will handle ~160lb/ft on an organic plate.

My 200mm Helix has a 335kg cover and is fine on a cable. Should have tried yours at JAE Paul...
next time we meet, you could try my clutch
 
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