1ZZ power limits

[woodypk]

Hi guys. On my road to seeking more from my '2 it got me wondering...

At what power/torque limits do things need changing/upgrading?

I've been looking at getting more power from my '2 to stop me from swapping it for something with a little more oomph. This lead me down the path I've just taken and decided to turbo my 1ZZ roadster.

While looking at figures and reading information on this forum, I see that there are a few turbo 1ZZ roadsters with a range of powers.

Starting with the standard power moving upwards, at what power/torque levels do you have to start to upgrade things such as (and please feel free to add things I've missed. The more information the better!):-

-Clutch
-injectors
-valves
-rods
-pistons
-other engine components?
-induction??
-cooling??
-gearbox
-fuel pump
-other stuff???

For example....: 'I want to turbo my roadster and I'd like to hit the magic figure of 260bhp and 240ft/lbs. What upgrades over standard will I need to be able to make my goal'

I know this is a little bit of an open ended question because you could say with infinite money, any amount of power is possible, but I've decided that I'm going to keep my '2 FOREVER because It's just a great car and I'd like to know what my options are and just generally increase my knowledge of these little beasts.

I know these things will have been mentioned over the years in various posts, but to have all the information in one topic with a title that can easily be searched will be very useful for me and might be useful for other new members who might be thinking about these things.

Cheers guys.

[m1tch]

The stock engine with high compression cast pistons and thin rods are ok for around 220bhp, gearbox should be ok to 250ft/lbs - gears 3 and 4 are weak and the Lotus guys usually break theirs fairly regularly.

I am going for mid 300s with my 1zz, will be running stock crank (think its good for about 600 as its forged), but upgraded rods and pistons. There are 2 options for pistons, either keep the close to stock bore and go to 79.5mm or bore the engine out and run 82mm pistons but then you would need Darton sleeves. I will be upgrading the 3rd and 4th gears in my C64 box to cope with the extra torque/peace of mind.

Other option is the 2zz swap which is quite common, there is also the K swap but not as common over here but is in the states.

My suggestions would be to run a low boost turbo setup, check out leethesparky's thread for a good setup.

Don't forget to also factor in the cost of a standalone ECU and dyno time.

-Clutch - needs upgrading and perhaps run a lighter flywheel
-injectors - run 2zz injectors or I believe VXR injectors fit with a small mod
-valves - Supertech lighter valves with upgraded springs and retainers to increase the RPM
-rods - Need to be upgraded to forged, stock rods are lightweight but can bend under boost
-pistons - Need to be upgraded due to the economy design - they are cast with the top ringland being close to the crown so can crack
-other engine components? ARP head studs, forced induction camshaft
-induction?? - Stock airbox with drop in is good, open cone isn't the best due to engine bay temps
-cooling?? - Mishimoto upgrades available
-gearbox - Weak 3rd and 4th gear, upgrade to E153 box (although heavier, expensive with poor ratios) or upgrade 3rd and 4th with the JUBA or SSR gearset
-fuel pump - Uprated Walbro fuel pump will suffice, best to upgrade to a return fuel system
-other stuff??? - ECU, Dyno time, Better brakes, Wideband O2 gauge

An alternative route is to increase the power to weight by removing weight from the car - its easier to do than modding the engine too much, I have already pulled a fair amount of weight out of my car and it still looks basically stock.

[shnazzle]

The above list need not all be done, remember  s:) s:)
Depends on what you're going for.

You won't need the valves/cams if you're staying 1zz and going turbo. Unless you plan to squeeze out the last 20hp, over the turbo increase, out of aggressive cams.

The SP240 turbo kit runs 230-240hp stable without any engine or gearbox gear work, fuel pumps, increased water cooling, etc. So 260, as long as torque is limited to the magical 250ft/lb, should be achievable on stock (refreshed) parts.

Obviously, the more you do to protect the engine, the more reliable it should be. (if reliability can even be discussed when talking about doubling power output)

[Carolyn]

A few years ago, a young friend brought me a Skyline engine for rebuilding.  He had, of course, managed to blow it up.  When asked 'How much horsepower can you get out of this ?', I replied 'How long do you want it to last?'

[m1tch]

Usually a case of: Cheap, Fast, Reliable - pick 2.

With regards to the valves and cams, I think I would want to run slightly uprated springs if I was going for an RPM increase to avoid valve float but the stock springs and valves should be fine at stock rpms.

[shnazzle]

Usually a case of: Cheap, Fast, Reliable - pick 2.

With regards to the valves and cams, I think I would want to run slightly uprated springs if I was going for an RPM increase to avoid valve float but the stock springs and valves should be fine at stock rpms.

Why would you want an rpm increase with a turbo setup? Surely the redline stock is already well into the very low efficiency margins of the turbo flow map for most suitable turbos.

Unless you run a bigger turbo at low boost maybe.. Dunno

[Ardent]

Can only speak of the tte setup, that mimics precisely what shnaz describes. Out of puff, long before the red line.

[woodypk]

Thanks for the replies guys.

I've started down this winding path to turbo-dom and I just have the figure of 260 bhp in my head. If I can get there with out massively upgrading the engine then I'm happy with that. Currently looking at finding the correct injectors on fuelperformance, the AEM 30-0300 wideband and the ACT HDSS on another site to get me there.

On a side note, I've heard before the Astra VXR injectors fit with a modification... 1) will they get me to 260 bhp without running them to the max 2) does the modification require some plastics shaving and the plug and play EV6 connnectors?

[jvanzyl]

You want to have a look at stupinks build thread regarding the vxr injectors...


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[AmeR]

Lotus Exige 440cc injectors are plug and play. That's what I have on my setup, running just over 270bhp, so am sure they'd suit your intentions.

[jvanzyl]

What's the cost of the lotus Vs the vxrs though?

And where's your build thread??

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[shnazzle]

I wonder if these are the ones in Helen's SP240...

[AmeR]

What's the cost of the lotus Vs the vxrs though?

And where's your build thread??

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Couldn't tell you I'm afraid. The injectors were purchased by the previous owner some years ago. However, if you have to purchase/produce adapters for the VXR ones, factor that in to the cost comparison.

My build thread only has my older HASS setup. I really need to get my act together and update it with the Apexi kit. It's on the list, honest!

[woodypk]

I think I have 440cc lotus ones in mine. There's not a lot of information online on the ones I have but I'm sure they're 440cc. I just thought these wouldn't be capable of putting out more that 240bhp. I've got the apexi FC too.

The past number on the injector is 23250-yw201 and ive already fitted them. They just plugged straight in.

[shnazzle]

MWR rates the 440cc at 235hp (at the wheels) without FPR and fuel return and 265 with FPR and fuel return.

So if you want to achieve 260, you're probably better off going for the vxrs

[woodypk]

Will the VXR make 260 without pushing them too hard?

[1979scotte]

440 injectors will make well over 240 bhp at the crank.
SP would have allowed plenty of head room and their kits made 235 no problem.
I think 400-500cc injectors are as big as you can go on most piggyback ECU.
Any bigger and you need standalone.
A rising rate FPR and a fuel return would be best for high power scenarios.

[woodypk]

I thought the Apexi Power FC was a stand alone?
Sorry, I'm a newb when it comes to this.

I'm after 260 at the wheels and I'd like to make sure they're not maxed out so allowing a little wiggle room.

[shnazzle]

I thought the Apexi Power FC was a stand alone?
Sorry, I'm a newb when it comes to this.

I'm after 260 at the wheels and I'd like to make sure they're not maxed out so allowing a little wiggle room.

Pfc is indeed a standalone. While being very well proven and used, bear in mind it's getting on a bit and there are better alternatives.

260 at the wheels I would go bigger than 440
470 should do absolutely fine long term

[1979scotte]

I thought the Apexi Power FC was a stand alone?
Sorry, I'm a newb when it comes to this.

I'm after 260 at the wheels and I'd like to make sure they're not maxed out so allowing a little wiggle room.

It is.
260 at the wheels that's a lot.

[woodypk]

Does the sp240 kit give a bhp figure quoted at the wheels or is this a crank figure which turns out lower at the wheel once drivetrain losses are taken into consideration?

[ChrisGB]

Does the sp240 kit give a bhp figure quoted at the wheels or is this a crank figure which turns out lower at the wheel once drivetrain losses are taken into consideration?

It's at the flywheel.

[woodypk]

I didn't expect that. I thought that would have been what it would read on the dyno. Which I assume is power measured at the wheel.

[1979scotte]

I didn't expect that. I thought that would have been what it would read on the dyno. Which I assume is power measured at the wheel.

It is rare that a UK power figure is quoted at the wheels.
That is far more common is the USA and Australia.
I prefer whp I believe it to be a more accurate figure.
Fly/crank numbers are all very approximate. No rolling road can get it 100%

[woodypk]

Wow really?

I thought all dyno results showed the power measured at the wheels. Since that's where the power is tested from when they put it on the rolling road.

You learn something new every day...