28 replies to this topic

[Wazzah]

Purchased a modified throttle body from Japan and it arrived today.

Also got an adjustable pressure regulator.

Fitted it all up today with the standard injector.

I don't have a fuel pressure but measured spring heights and added 1mm of adjustment.

Seems to rev more freely and had a small flat spot.

Adjusted the regulator a half  turn and that fixed the flat spot.

I found an injector that flows 810cc and that is on the way from the US.

Out of an SPI shitbox dodge which appeals to me.

I'll fit that when it turns up back the pressure of that half turn and see were I'm at.

The regulator has a vacuum enabled spring chamber that effectively weakens the spring load at idle, off throttle and part throttle situations.

This seems to work nicely.

Runs just like an SPI should.

I have used the heat control flap vacuum supply as my vacuum source.

May not need it with the 810cc injector.

I had been persevering with an SC Delta 400 and their throttle body for the last 12 months and swapped it back for standard SPI gear in frustration.

I'd already paid for the Japanese TB when I recently learned that SC have released firmware that actually caters for a JDM SPI like mine.

I have a dilemma looming and will evaluate both systems ahead of my rebuild.

I have a 5 speed lost on a corona boat somewhere between here and the UK.

I have an SC tough crank and SC rods, MED lightened flywheel, SW5, some 1310cc pistons and a Quaife to fit once the gearbox is here.

I think I can achieve a reliable 90 hp with SPI gear and maybe 95 hp with the SC Delta gear.

My preference is SPI at the moment as I like the load sensing (MAP) of the rover stuff.

At the moment I'm running an LCB, SC Supersport head, K&N filter in the standard airbox, Cooper intake and 1.5 rockers.

I feel I'm making what the Cooper kits say they can except i'm in front of their SPI kit because of the 45mm TB.

Very promising.

Waz

[dmandan]

Let me know if You find yourself holding a spare ECU....

[Pops_Guild]

Thanks Wazzah for the post! Interesting stuff! 

 

I have also got one of those on order from Japan but was on the fence about whether I should or would need the fuel pressure regulator. Seemed a lot of extra £ for something I wasn't sure if it was needed or whether I would be able to work out how to properly set it up. I get why it may be useful but as there's not a lot of info on this side of things for SPI, your post is about it :)

 

What you say about the spring lengths and adjustment makes sense. I assume in the instructions for the regulator it explains how the adjustment it has affects the regulation and fuel pressure? 

 

When you say you adjusted it half a turn, was that restricting or opening up? 

 

You said you've used the heat control flap vacuum supply as the vacuum source for the regulator, that makes sense, but how have you routed that pipe? I can't figure that out in my head with any type of air filter/box.

 

 

Did you by chance try the 45mm throttle body without the adjustable regulator? 

 

 

My mini is pretty much a bog standard SPI Cooper other than the LCB, K&N and MED 1.3 rockers. I'm not expecting much of a difference from using the 45mm body but I do think the Rover SPI setup has a lot of good things about it so I'm doing it for the science of it. I'm changing one thing at a time and seeing what it does :)

 

 

 

Any chance you could share some pictures of the setup, regulator etc? 

Did you by chance try the 45mm throttle body without the adjustable regulator? Do you think it would likely suffer from the flat spot issue?

[Wazzah]

Yeah Pops I reckon it will run too lean with all that extra air and no extra fuel.

From my initial measurement I screwed the adjuster in thus increasing the fuel pressure which should allow more injector squirt in the available pulse width.

When I got home tonight I screwed it in another half turn and it is clearly now over fuelling.

So I went back the half turn and then back another quarter.

Seems to be running sweeter now.

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[Wazzah]

Almost forgot the most important thing. 

The induction noise is louder and way cooler.

[Pops_Guild]

Thanks for the photo and info. Yep that's what I thought too (would be lean).

 

I figured I'd need to ease the vacuum pipe through somewhere!

 

...nice to hear there's a audio benefit too :)

 

I'll keep this thread updated with my adventures too!

[brivinci]

Forget my question on the other thread. This is great info!

 

I would imagine that this is not really a necessary upgrade with a standard car. As its been said for ages, the SPi is really limited to about 85bhp by the ECU, not really any other restrictions. I guess only true rolling road numbers would really tell the full story. 

 

My current setup is a 1310 with Piper BP255 cam timed in, Calver ported head, K&N drop in, LCB, no CAT and twin-box rear section...as far as HP gain is concerned. Car runs/feels nice but when I pulled the plugs, they did look a little lean. That fuel pressure reg is VERY cool and great to see pix as I was not sure where it fitted. Makes total sense now. 

 

I am here in the US should you ever need any parts on this end. I'll have to look into that injector.

 

My worry is always the ECU. If the only way around to get more then around 85bhp is to trick it, I am not sure how comfortable I feel with that. Way too many variables that should not be left to guessing or assuming. With all the work that company is going in Japan, I would love to see some numbers from them. I am going to reach out and see.

[Wazzah]

So the injector Bosch part number is 0280 150 810 and it flows 810 cc/min.

When I receive and fit it I'll report back as to whether it fits and works.

The standard Rover injector is 0280 150 682 ant it flows 680 cc.

It's not really tricking the ECU as such as it only knows to deliver a set pulse width according to throttle position and map load.

The trick is to achieve a larger but balanced amount of fuel that matches the extra air flow.

The adjustable regulator appears to help that balancing act by pulling back on the regulators diaphragm and dumping pressure so there is less squirt when the injector is open.

I honestly thought I would have more trouble.

It took me an hour to fit and Ive probably spent an hour on adjustments.

I have a slightly rich idle but it runs like a good SPI should.

Definitely torquier  when measured through the arse dyno and pulls a lot harder up to red line.

Easily pulled 120 kmh in third and 155 in top before I ran out of road.

I've started an economy run since filling up last night.

I was getting 42 mpg so it will be interesting to see the new figures.

Apart from my cylinder head I rate this 45mm TB and Reg the best upgrade I've done so far.

How many times have we all fiited an LCB for no real improvement.

Same with a K & N.

I am know thinking about the 48mm version of this TB.

[dmandan]

Almost forgot the most important thing. 

The induction noise is louder and way cooler.

 

love the induction noise can't get enough

[bluedragon]

My concern with just upping the fuel pressure is that unless the SPi system adjusts fuel delivery via feedback, it will squirt too much fuel at lower loads. 

 

This means at best poorer fuel economy, at worst, washing oil off the cylinder bores at lower load levels due to excess fuel. I do not know if the SPi's have this level of fuel control beyond that needed for emissions purposes.

 

For sure, the more sophisticated MPi does not, as it has no meter to measure air flow. Ploys such as raising the fuel pressure have caused exactly these types of problems for MPis, and it's hard to believe the SPi is more advanced in this regard (as it doesn't have a airflow meter either.)

 

 

Dave

[IntMilkBrilliant]

I am know thinking about the 48mm version of this TB.

The 48mm version costs quite a bit more, and takes a few weeks but I have spare throttle bodies if required

Edited by IntMilkBrilliant, 07 May 2020 - 02:30 AM.

[sonscar]

As someone who has Efi equipped cars(mgb1800 and mgb3500 v8) with full data logging and mapping with wideband lambda I find tuning like this questionable.Do you know what AFR you are running?do you adjust the timing to suit the new mixtures?
Not running an injected mini I asked on another thread mentioning the ECU "learning" had the ECU the capacity to learn?Just interested,Steve..

[brivinci]

That is what I was thinking. These types of mods should really not be left to guesswork or what "feels" right, in my option. I'd love to see some actual data to back up and confirm things.

 

IntMilkBrilliant, welcome. Is this your company? Really do love the concept and what your aim is. Would love to hear what else you have in the pipeline and if you are looking for ideas.

[IntMilkBrilliant]

IntMilkBrilliant, welcome. Is this your company? Really do love the concept and what your aim is. Would love to hear what else you have in the pipeline and if you are looking for ideas.

This is my company, yes. I've spent years building it, however I'm not here to preach or sell anything, just as a spectator. I've been registered for years but the spike in referrals to my website brought me back. Ideas are always welcome.

[brivinci]

Great to have you here. I found your site from the USA forum under mini mania. There is an ongoing thread about the terrible quality of runner these days. Your site came up as a possible source of some quality items.

Have you run a side by side dyno run with the 45mm throttle vs standard?