Next Steps Please!?

[Ihtisham Rauf]

Hi,

I am looking for advice to get more power/torque/better acceleration from a CGA3 on a CG10 gearbox. It has the standard bolt on mods:
Wilder inlet cam, GA16 airbox, Janspeed manifold, 4.2kg light flywheel, CG10 crank pulley, injectors. Current 0-60 is around 7.2 sec and I reckon its around 105bhp.

but unsure what the best next steps are as I want to hit wilder bhp figures (130bhp target?) and also a 0-60 of under 6.5 sec? (too ambitious?!) Please help me!

I do have some ideas but I don't know enough about this so hoping people can help me with gaps in my knowledge.

I know some people on this forum have achieved 130bhp on CGA3's so need some wisdom!

Appreciate any help as always!

 

[.Maarten]

Get it mapped.

Some possible next steps:
Intake manifold, thinner head gasket of a head shave. Higher comp pistons, ITB's Or a turbo. Almost everything will be expensive.

 

[Ihtisham Rauf]

Get it mapped.

Some possible next steps:
Intake manifold, thinner head gasket of a head shave. Higher comp pistons, ITB's Or a turbo. Almost everything will be expensive.

For now, I want to stick with creating an N/A monster! That's some really good ideas so thank you!

Its a shame everything from now on will be expensive.

Any idea which pistons would be the good option to raise compression? (I have seen people use Corsa pistons I think?)
And what could be done regarding the inlet manifold?

 

[SuperUno]

Read my blog (car specs) to see what we run, engine made 126bhp when mapped by Fusion Motorsport. That was old engine which was standard used bottom end, so new/current engine should be about 130bhp.

Running the 4.92 final drive makes a real difference and worth it. http://www.mattendean.co.uk/

 

[.Maarten]

Custom inlet mani. Yes Corsa pistons can be fitted with some engine work. Also A14net pistons can be made to fit.

Cams are also a good upgrade. Like catcams with stiffer valve springs to be able to raise the limiter a bit.

 

[Ihtisham Rauf]

Read my blog (car specs) to see what we run, engine made 126bhp when mapped by Fusion Motorsport. That was old engine which was standard used bottom end, so new/current engine should be about 130bhp.

Running the 4.92 final drive makes a real difference and worth it. http://www.mattendean.co.uk/

Thanks for the reply. Am reading the blog now

 

[Ihtisham Rauf]

Custom inlet mani. Yes Corsa pistons can be fitted with some engine work. Also A14net pistons can be made to fit.

Cams are also a good upgrade. Like catcams with stiffer valve springs to be able to raise the limiter a bit.

Will look into pistons.

Do you know what sort of compression ratio can be achieved with A14net pistons?

 

[Ihtisham Rauf]

Read my blog (car specs) to see what we run, engine made 126bhp when mapped by Fusion Motorsport. That was old engine which was standard used bottom end, so new/current engine should be about 130bhp.

Running the 4.92 final drive makes a real difference and worth it. http://www.mattendean.co.uk/

So I have read through the blog, amazing stuff!

Yes the 1.0 gearbox does indeed make a big difference.

Just 2 questions hope you don't mind answering please:
where did you get your head ported and polished from?
And how much does your lightened flywheel weigh?

Thanks!

 

[SuperUno]

The head came from Matt Humphris in a package of parts I bought from him, I don't think he did the head work but had it done by someone else.

The 1Ltr box is a good improvement with the 4.4 diff, the 4.92 is another big step up again (plus it is semi-helical so sounds ace).

The flywheel I didn't weigh it before fitting (time was very tight at that point before a rally, so nice things like that went out the window!). I would imagine it was about 5kgs, I was lucky and got it cheap (£25 in a rally Micra spares sale I found near me)

 

[SuperUno]

If you haven't make time to read Paul's blog, the whole lot is worth a read. I learnt a lot of Micra advice from it.

Plus of course remove as much weight as you can.....

 

[Ihtisham Rauf]

If you haven't make time to read Paul's blog, the whole lot is worth a read. I learnt a lot of Micra advice from it.

Plus of course remove as much weight as you can.....

Yes I've read a lot more of it as of now!

The lightened battery seems like a good shout so will look into this.

Also what a bargain on the flywheel!

 

[SuperUno]

I am trying an even lighter battery option in the ZR at the moment, one of these which is even lighter and cheap. If it works on the ZR I will fit one to the Micra as well https://www.ebay.co.uk/itm/Lucas-12...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

 

[Ihtisham Rauf]

Thanks for the advice to all, really appreciated.

Currently going to save up but at least I now have an idea of next steps:

1. I'm thinking 2mm headskim to raise compression, this would pair nicely with the Corsa or A14net pistons.
2. Custom inlet manifold - have heard of starlet manifold being welded onto Micra inlet flange and a bored out throttle body? (not sure which throttle body yet though)
3. A remap but just struggling to get any info from Mark
4. Lose weight - light battery seems like a cool idea, its something I just never thought of so thanks to SuperUno!

 

[.Maarten]

A14net pistons would raise cr a bit. Not to much. I don’t know the specific cr. Also depends a lot of the head skim.

you can also ask tornado systems for a remap. They can remap the stock coilpack ecu.

 

[Ihtisham Rauf]

A14net pistons would raise cr a bit. Not to much. I don’t know the specific cr. Also depends a lot of the head skim.

you can also ask tornado systems for a remap. They can remap the stock coilpack ecu.

Yes I emailed to ask to get some info regarding remap but never heard back from them
Might just ring them today.

 

[Scrubworks]

If you're removing the head for a skim you should definitely consider putting aftermarket cams in it. I gather they are worth their weight in gold. I'm building a CG13 in an NA style build very similar to yours, and the two main parts of my build are better cams from catcams, and using CG10 pistons to raise the compression, though since you have a CGA3 I don't think that latter option is one you can do. Also if you do cams a remap will be pretty much mandatory.

As for losing weight, do you take back seat passengers often, or at all? If not, you can lose a considerable amount of weight by binning the back seats. It's free! You can also then replace the front seat with fixed bucket seats to save even more weight, but that unfortunately is not free.

 

[Ihtisham Rauf]

If you're removing the head for a skim you should definitely consider putting aftermarket cams in it. I gather they are worth their weight in gold. I'm building a CG13 in an NA style build very similar to yours, and the two main parts of my build are better cams from catcams, and using CG10 pistons to raise the compression, though since you have a CGA3 I don't think that latter option is one you can do. Also if you do cams a remap will be pretty much mandatory.

As for losing weight, do you take back seat passengers often, or at all? If not, you can lose a considerable amount of weight by binning the back seats. It's free! You can also then replace the front seat with fixed bucket seats to save even more weight, but that unfortunately is not free.

That's some very good advice there Scrubworks!

Yes I already have a slightly wilder inlet cam - its 250deg and 9mm lift. I know its not too extreme but I wanted a torquey car, and yes I 100% agree its one of the best, if not the best mod I did (apart from swapping the engine!).
Didn't change the exhaust cam though as that pushes the powerband far too high for my liking.
I haven't actually got it mapped yet even though it has all these mods - stock ECU is managing well!. Nistune etc aren't an option on my coilpack ECU, and me and Tornado Systems are having communication problems in that they haven't replied to my enquiries and they're the only ones that can remap my coilpack ECU.

Yes I regularly have passengers in the back so unfortunately removing rear seats isn't an option (or maybe I should make people crawl up in the boot lol!)

CG10 pistons are not an option as you say. I've been told A14net pistons do raise the compression slightly, so will be a good mod along with a 2mm head skim. Based on what I have read on the forum, the head skim + pistons will give roughly 11.7:1 compression ratio, although I really need to learn the proper maths behind calculating the compression ratio for a given head skim!

Good luck for your project, do you have a blog?

 

[Scrubworks]

That's some very good advice there Scrubworks!

Yes I already have a slightly wilder inlet cam - its 250deg and 9mm lift. I know its not too extreme but I wanted a torquey car, and yes I 100% agree its one of the best, if not the best mod I did (apart from swapping the engine!).
Didn't change the exhaust cam though as that pushes the powerband far too high for my liking.
I haven't actually got it mapped yet even though it has all these mods - stock ECU is managing well!. Nistune etc aren't an option on my coilpack ECU, and me and Tornado Systems are having communication problems in that they haven't replied to my enquiries and they're the only ones that can remap my coilpack ECU.

Yes I regularly have passengers in the back so unfortunately removing rear seats isn't an option (or maybe I should make people crawl up in the boot lol!)

CG10 pistons are not an option as you say. I've been told A14net pistons do raise the compression slightly, so will be a good mod along with a 2mm head skim. Based on what I have read on the forum, the head skim + pistons will give roughly 11.7:1 compression ratio, although I really need to learn the proper maths behind calculating the compression ratio for a given head skim!

Good luck for your project, do you have a blog?

Yeah my choice of cams is similar. I'm going for 253 duration, but slightly less lift at 8.7mm. That's a matching pair of cams, but are mild enough to still make decent torque, hopefully. Although, I wouldn't mind a high powerband; I'm considering having the rotating assembly properly balanced to help it rev higher.

That's very frustrating that they won't respond, I hate it when companies are crap at communication. I'm going to probably take mine to Fusion Motorsport for a Nistune like you say. I think that 11.7:1 is similar to what compression I'll be achieving.

I do have a blog, but it's still early days, mostly disassembling a donor engine at the moment.

 

[Ihtisham Rauf]

Yeah my choice of cams is similar. I'm going for 253 duration, but slightly less lift at 8.7mm. That's a matching pair of cams, but are mild enough to still make decent torque, hopefully. Although, I wouldn't mind a high powerband; I'm considering having the rotating assembly properly balanced to help it rev higher.

That's very frustrating that they won't respond, I hate it when companies are crap at communication. I'm going to probably take mine to Fusion Motorsport for a Nistune like you say. I think that 11.7:1 is similar to what compression I'll be achieving.

I do have a blog, but it's still early days, mostly disassembling a donor engine at the moment.

Sounds excellent. Do please let me know how the cams feel when in, as I may also consider getting an wilder exhaust cam.

Yes indeed it is annoying, but I am going to ring them within the next few days.

Look forward to reading your blog updates as it seems we both have a very similar project, given the 250deg cams and 11.7 target compression ratio!

 

[John_D]

God all of this brings back memories, I was doing the same sort of thing, over 50 years ago, with an 850 Mini. Block line bored for white metal cam bearings (standard the cam ran in the cast iron block), skimmed, flowed, combustion chamber reshaped , large valve head, with double valve springs. Cam (2A948) from a 997 Cooper, which was much 'sportier' than the 'Cooper S' cam. Replaced the single width timing chain and timing gears with Cooper S duplex ones. Whole engine lightened and balanced and conrods polished. 'Downton' inlet manifold, with a single 1.5" SU carb and Cooper 3 branch manifold.
Sadly dyno's weren't available then , so no idea what the power output was, but suffice to say the car went like something smelly off of a shovel! Bearing in mind that apparently the standard 'A' series engine would suffer a timing chain failure at about 6000rpm and a crank failure at around 6500 if the timing chain hadn't already gone, my engine happily revved to 8000rpm, though in the interest of reliability I kept it down to 7500, but it ran right up to 7000 in top gear, equating to a true 105mph, which in the late 1960's made it faster than the vast majority of cars then around. Wish I still had that engine to put back in a Mini rebuild....

 

[Ihtisham Rauf]

God all of this brings back memories, I was doing the same sort of thing, over 50 years ago, with an 850 Mini. Block line bored for white metal cam bearings (standard the cam ran in the cast iron block), skimmed, flowed, combustion chamber reshaped , large valve head, with double valve springs. Cam (2A948) from a 997 Cooper, which was much 'sportier' than the 'Cooper S' cam. Replaced the single width timing chain and timing gears with Cooper S duplex ones. Whole engine lightened and balanced and conrods polished. 'Downton' inlet manifold, with a single 1.5" SU carb and Cooper 3 branch manifold.
Sadly dyno's weren't available then , so no idea what the power output was, but suffice to say the car went like something smelly off of a shovel! Bearing in mind that apparently the standard 'A' series engine would suffer a timing chain failure at about 6000rpm and a crank failure at around 6500 if the timing chain hadn't already gone, my engine happily revved to 8000rpm, though in the interest of reliability I kept it down to 7500, but it ran right up to 7000 in top gear, equating to a true 105mph, which in the late 1960's made it faster than the vast majority of cars then around. Wish I still had that engine to put back in a Mini rebuild....

Wow what a read!

Back then, I guess the M1 motorway was the dyno...is that where you got it to 105mph?

 

[Ihtisham Rauf]

.

 

[John_D]

Wow what a read!

Back then, I guess the M1 motorway was the dyno...is that where you got it to 105mph?

With the relatively low gearing and very low weight of the car (under 600Kg, which is about 220Kg less than a standard K11!) flat out in top gear was available just about anywhere that there was a mile or two of straight road

 

[Ihtisham Rauf]

With the relatively low gearing and very low weight of the car (under 600Kg, which is about 220Kg less than a standard K11!) flat out in top gear was available just about anywhere that there was a mile or two of straight road

Under 600kg is amazing. What sort of bhp per tonne do you reckon it was?

 

[John_D]

Under 600kg is amazing. What sort of bhp per tonne do you reckon it was?

Probably around 120bhp/ton, quite respectable. I forgot to add to the list of lightened and balanced parts, the flywheel and the valve rockers, which were modified like these:-

And that I fitted an oil cooler and a VERY large oil pressure light on the dash, operated by a 20psi oil pressure switch, to give maximum warning if a drop in oil pressure was detected.
The main limitation of the 848cc engine, and it's ability to rev beyond 7500rpm reliably was the fact that it had pinchbolt conrods, like these (as found in Model T fords!) :-

So no small end bearings, the gudgeon pin was clamped in the con rod and it's bearing surface, for rotation, was the bore in the piston. The addition of fully floating conrods would make 10,000 rpm possible on a well balanced 'A series' engine.
One other piece of historic information is that 105 octane, 5* leaded petrol was available everywhere and you could get four gallons and get change out of £1! (4s/11d a gallon). This however has to be tempered with the knowledge that as an apprentice scientific instrument maker, I was on less than £10 for a 42 hour week.

 

[Ihtisham Rauf]

Probably around 120bhp/ton, quite respectable. I forgot to add to the list of lightened and balanced parts, the flywheel and the valve rockers, which were modified like these:-
View attachment 65852
And that I fitted an oil cooler and a VERY large oil pressure light on the dash, operated by a 20psi oil pressure switch, to give maximum warning if a drop in oil pressure was detected.
The main limitation of the 848cc engine, and it's ability to rev beyond 7500rpm reliably was the fact that it had pinchbolt conrods, like these (as found in Model T fords!) :-
View attachment 65853
So no small end bearings, the gudgeon pin was clamped in the con rod and it's bearing surface, for rotation, was the bore in the piston. The addition of fully floating conrods would make 10,000 rpm possible on a well balanced 'A series' engine.
One other piece of historic information is that 105 octane, 5* leaded petrol was available everywhere and you could get four gallons and get change out of £1! (4s/11d a gallon). This however has to be tempered with the knowledge that as an apprentice scientific instrument maker, I was on less than £10 for a 42 hour week.

I’ve learnt so much in this one post lol!

 

[Scrubworks]

God all of this brings back memories, I was doing the same sort of thing, over 50 years ago, with an 850 Mini. Block line bored for white metal cam bearings (standard the cam ran in the cast iron block), skimmed, flowed, combustion chamber reshaped , large valve head, with double valve springs. Cam (2A948) from a 997 Cooper, which was much 'sportier' than the 'Cooper S' cam. Replaced the single width timing chain and timing gears with Cooper S duplex ones. Whole engine lightened and balanced and conrods polished. 'Downton' inlet manifold, with a single 1.5" SU carb and Cooper 3 branch manifold.
Sadly dyno's weren't available then , so no idea what the power output was, but suffice to say the car went like something smelly off of a shovel! Bearing in mind that apparently the standard 'A' series engine would suffer a timing chain failure at about 6000rpm and a crank failure at around 6500 if the timing chain hadn't already gone, my engine happily revved to 8000rpm, though in the interest of reliability I kept it down to 7500, but it ran right up to 7000 in top gear, equating to a true 105mph, which in the late 1960's made it faster than the vast majority of cars then around. Wish I still had that engine to put back in a Mini rebuild....

I apprenticed on classic cars. I really wanted to build a fast Mini in the old school way, but they're just too expensive now. I spent the same amount of money on my project Micra, and a donor car, as it would have cost me to buy a rebuilt 12G295 cylinder head! Add in the more advanced tech and the slight improvement in build quality over BL, and I think the K11 makes a good spiritual successor to the Mini. I certainly find it more Mini-ish than the BMW Mini.

 

[fuzzy-hair-man]

Wish I still had that engine to put back in a Mini rebuild....

Put a cg13de in a mini, they fit really well and standard equate in performance (butt dyno verified) about the same as a 1310 A series, the cg13de loses a bit of weight to the A series so power to weight can improve again. Cheapest and easiest way to get a twin cam, 16v, 5 bearing crank, 5 speed gearbox running in it's own oil, multi port efi, alloy block 1275 I know of...