16 replies to this topic

[nouniard]

Thought I'd get some group feedback on a final drive ratio. My SPi is currently undergoing a swap from automatic to manual and we're rebuilding the new engine and gearbox. I'm looking to get a car that's suitable for daily duties (whether or not that continues...it was my only car for 5 years) and long distance with lots of highway driving here in the US. I've specifically been looking at the 2.95 & 2.76 final drives. My old auto was a 3.27 and got pretty loud while I was in Germany on the autobahn...engine was getting pretty tired too. I intend to line the interior with plenty of sound deadening to lower the road noise as well as make my planned I.C.E. worth the effort.

 

To hopefully compensate for the loss in acceleration with the taller drives I'm building it up with some upgraded bits. This is what I have planned out thus far:

 

- 1275cc bored +0.20" to 1293

- 'Stage 3' Head, (likely from Calver [Sport Spec - 35.7/29.5 valves])

- Swift Sw5 Cam

- SPi 'Cooper' (MNE101070) ECU

- Standard Rockers

- Simplex with IWISS Chain

- Maniflow Exhaust (perhaps a complete system)

- K&N Air Filter (direct replacement)

- 12" wheels (145/70R12)

- Smiffy's Bits (should add a few BHP...)

 

 

Anyone run these final drives in their standard/upgraded Minis?

Edited by nouniard, 03 April 2015 - 02:44 AM.

[IainStallard]

Sounds like a good engine spec there for an spi. I'd however buy a maniflow lcb and complete the whole exhaust system with maniflow parts. K&N element filter in the airbox may also help.

I have used my mini every day for the past 2 and a half years and have done about 30,000 miles in it! I have a 3.1 final drive in mine with all the factory sound deadening and its not too loud. Can cruise at 75mph at 4000rpm quite happily all day

[lawrie124]

2.95 or 3.1 is great for long journeys. We take cars on a 1,000 mile round trip to the Nurburgring each year and they cruise nicely at motorway speeds.

[brivinci]

That sounds exactly like my setup. Might be good to thinking about an adjustable timing set to get the most out of the cam.

 

What is standard in these? 2.95 right? I was thinking of going with a 3.44 to add some punch but left it stock on the last build. Go here if you want see the differences from Guesswork. VERY helpful information.

 

http://www.guess-wor.../Tech/ratio.htm

[brivinci]

Wait, what tires are you running is that size??? If your planning on making your car a bit faster, perhaps some tires with a bit more bite are in order. Yoko A539 are the sensible option and are 165/60-12

[nouniard]

It still has on it's winter Nankang tires. I always sourced tires locally while I was overseas. That won't be the case here in the US.

[brivinci]

Well, we are in the same boat as I'm here in the US as well. I still source me tires overseas though:-)

[nouniard]

Sounds like a good engine spec there for an spi. I'd however buy a maniflow lcb and complete the whole exhaust system with maniflow parts. K&N element filter in the airbox may also help.

I'm now leaning towards a complete system from Maniflow. A K&N is part of the current spec. The plan is just the replacement element in the air box. I had the cone K&N on the auto and it was fine except for the drone of the induction which wears on you on longer journeys...

[Fossy313]

Noun,

If your spi has the same airbox as the mpi, mod it like this with the filter element...lots of tests done and it rises above the cone filter :)

http://www.cloud-nin...tech_airbox.htm

Good luck with your mods!

Current spec I'm heading towards with an engine build in July with my mpi is

Currently

Maniflow injection stage one twin box exhaust
LCB manifold
Keith calver GT spec cylinder head
(Runs very nice)

After rebuild
3.2 FD (a compromise on 3.1 as it's what I have managed to get hold of in my donor box)
Calver forged 1:4 rocker set
Piper255 injection cam
Uprated simplex chain and timing gears
Uprated turbo clutch
Lightened and balanced flywheel

Should make a nice cruising daily drive with bags of torque for the fun country lanes in the summer.

Edited by Fossy313, 06 April 2015 - 07:04 PM.

[nouniard]

Thanks Fossy. They're similar so I should be able to modify it. I've just placed an order with Calver for the GT spec head. He said the 'Sport Spec' head is overkill for my needs.

 

Look forward to seeing how your build turns out. Once the head and all other required parts arrive mine should be built around the same time.

 

Any reason for the Piper 255 over Swift's Sw5 or the Kent MD274?

[Fossy313]

Awesome mate,

I spoke to Keith on the subject and he is pretty adamant that because of he ECU issues the cam is one of the best he has used keeping it under the ECU capabilities, mines a daily drive so I wanted a nice idle and torque through the Rev range, it's what he suggested and swares by it

If you can mate he did suggest I went into zinio(good it) and get his mini expert issue 1 it's 4.99 and you read it online of/iPad its his very first issue in the mini magazine and goes through the whole tuning rebuild of the engine and gearbox, it's what the Haynes doesn't tell you and for 4.99 it's probably the best thing I have bought to date, he talks about the " stage 3" injection there and the 255 piper.

He also is very much against 1:5 roller rockers and so are a few of the old timers on here so I'm getting a set of his forged 1:4 as above

Be good to message you mate as it sounds like we could be taking the same things at the same time..

Are you rebuilding yourself??? First time??

Apologise I'm on my phone for the typos

Craig

Edited by Fossy313, 09 April 2015 - 08:39 PM.

[brivinci]

Is there only one issue of Mini Experts? That sounds REALLY great.

[nouniard]

I'll have to grab that issue! I've read similar things about the 1:5 rockers so I'm keeping away as well. Interesting info on the Piper cam...I've heard little about to up to this point and mostly great things about the Sw5 cam.

 

I took the engine apart at Steve Gibbs' (of Cooper Tune Racing) garage but he'll be doing most of the rebuilding (with me watching/learning/jotting down/helping). He's been at it for decades with a racing history as well.

 

Like I said, I've had the Mini as a daily for 5 years and have done a lot of regular maintenance and upkeep but this is quite a steep jump for me so I'd rather not mess it up. Is yours a DIY?

 

We'll definitely have to message each other. I'll likely make a build thread on the forums.

[Fossy313]

Yes mate total DIY for me, whether it goes well or not will be another matter! I hate putting my cars into the garage and the mini is something great to learn on,

No there are more mini expert issues mate but that's the first one Keith wrote and it's probably one of the best!!

Nice to know you have some help noun! Our club over here is pretty handy too and the chairman is a mini wizz so that's where my help will be coming from :)!

[brivinci]

Hate to be a pain but can you post a pic of the cover of that mag? I only see one when I search.

Keith told me the same thing about the 1.5s, especially with the sw5 cam. He prefers the piper or Kent but says the Sw5, particularly the SW5-07 cam is really nice and works well in the SPi cars.