Andrew's Gemini KOOP

[Alistair]

Sweet man, itb'd 6 with auto attached would be rank though. Would cost fockall more to pop a w box behind it while you're doing it.

Also, get another lambo.

[Guest]

Epic plans but don't make this another deafrattle supra by going auto. That kind of engine needs a manual box, W58s come cheap enough

[mikuni]

Awesome, I like the plans! Surprised to see 2JZ written in there to be honest, I was expecting something in a V configuration. Good stuff though, I've measured them up before and pretty certain one would go in without too much trouble, just moving the radiator forward under the radiator support panel, like I've done in my Chevette. Heaps of room either side for manifolds and throttles too.

I'm even not too worried about the auto, will make for an awesome little coupe cruiser. Though if you are doing a 2JZ on throttles, with an electronically controlled auto, how do you control the gearbox? Just use the existing gearbox ecu and send it what ever signals it needs from the link (megsquirt etc)?

[R100]

Yeah i have a couple of W boxes in my shed. Not to worry. It will get a manual befor cert time. Just need to keep my eye out for a bellhousing, clutch and flywheel.

Have the 2JZ ready to go in with auto attached, main priority is to get it drivable.

Will be attacking this project in two weeks.

[R100]

Awesome, I like the plans! Surprised to see 2JZ written in there to be honest, I was expecting something in a V configuration. Good stuff though, I've measured them up before and pretty certain one would go in without too much trouble, just moving the radiator forward under the radiator support panel, like I've done in my Chevette. Heaps of room either side for manifolds and throttles too.

I'm even not too worried about the auto, will make for an awesome little coupe cruiser. Though if you are doing a 2JZ on throttles, with an electronically controlled auto, how do you control the gearbox? Just use the existing gearbox ecu and send it what ever signals it needs from the link (megsquirt etc)?

The itbs will go on when i fit the manual. Im going to see if i can run the factory ECU with the 6 ITB's first. The 2JZ doesnt run a airflow meter, just a MAP. Will be interesting to see if it works, in theory it should providing the map sensor gets the same readings as it did with the factory manifold.

I will be removing the factory gemini heater box, cutting the firewall back to allow the 2JZ to fit. Heaters are very impoertant to me so ill source another header box from something to fit under the glovebox.

Below is a piccy of cutlow's JZ engine in a gem from ozzy.

http://i179.photobucket.com/albums/w297 ... e001-4.jpg

[mikuni]

Holy crap. Are you going to cut that much out to fit it? It might handle semi-decent with the engine sitting that far back, but its a little bit of an undertaking compared to just dropping it in where it fits. Would also mean selector from a big gearbox like the W55 would be quite far back too.

[lowlancer]

Auto would be fucking cool.

[Jase]

thanks for giving it a good home Andy,

had some mean flash backs with you following me along the motorway.

i think it still looks good slightly rat,

I also have CDT flares if you want to paint it and fit more rim

[CUL8R]

Nice work, if Hunted doesnt want my Cobra rear springs they can be yours for cheaps, uprated & lowered... (although probably not low enough for your liking)

Auto would be sweet in something that doesnt in reality weigh that much..

[Jase]

lol have another look chris

i set it fairly low from the outset

[Spencer]

The itbs will go on when i fit the manual. Im going to see if i can run the factory ECU with the 6 ITB's first. The 2JZ doesnt run a airflow meter, just a MAP. Will be interesting to see if it works, in theory it should providing the map sensor gets the same readings as it did with the factory manifold.

The pressure map from ITB's is way different to single throttle with plenum. It will only work OK at WOT and even then not so hot, It WILL bog horribly everywhere else

[R100]

The itbs will go on when i fit the manual. Im going to see if i can run the factory ECU with the 6 ITB's first. The 2JZ doesnt run a airflow meter, just a MAP. Will be interesting to see if it works, in theory it should providing the map sensor gets the same readings as it did with the factory manifold.

The pressure map from ITB's is way different to single throttle with plenum. It will only work OK at WOT and even then not so hot, It WILL bog horribly everywhere else

Oh kool someones tried it. What engine have you seen or done this too ? Its great getting knowledge from people who have tried things first hand as most people just talk out there ass when they have opinions on things.

How did you hook up the MAP vacum lines ? I was thinking of running six 5-6mm lines off each throttle and connecting to a small plenum (500mls) then taking the MAP off that. If all else fails i can go aftermarket which will give me the best outcome at the end of the day.

[R100]

Would also mean selector from a big gearbox like the W55 would be quite far back too.

Good point, something i hadnt thought much about. Gear lever must come out as close as possible to the factory location or it wont look right. Mmmm will cross this bridge when i come to it.

[mikuni]

I was thinking of running six 5-6mm lines off each throttle and connecting to a small plenum (500mls) then taking the MAP off that. If all else fails i can go aftermarket which will give me the best outcome at the end of the day.

We tried that on my chevette and it still didn't give a decent pressure reading, it just dropped away as soon as the throttles opened. This is with a link g3 ecu too, but we could get no linear rate of pressure change from any kind of vacuum accumulator.

I have considered trying to run throttles on a factory ecu again but I think it would actually be easier if you DID have an airflow meter, because then you can run the throttles with a plenum style sealed airbox and have the air coming into it through the afm, rather than a map trying to get precise pressure readings. Would also need to fit the factory throttle position sensor to the throttles too and hope that it was vaguely accurate.

All in all, its very unlikely to work but the worst you can do it try, and have the backup of just chucking an after market ecu on there when it all turns pear shaped.

[Spencer]

I tried on a smallport 4age, a long time ago now! tapped each runner into a accumulator, the accumulator makes no difference. Once you've sat and tuned a few cars, you will realise it will never work, the map readings from individual throttles to single + plenum are just too different. Manifold pressure is not a direct relationship to airflow, you can use it to measure airflow for a given engine. But as soon as the intake design is changed as dramatically as going to throttles, or installing cams etc it is useless. On the other hand a AFM or MAF measures actual airflow into the engine and fuels accordinly, so as brad said individual throttles with a plenum and AFM will work on a factory ECU

[KKtrips]

Rock a log style manifold with 6 x ITB's - LOL

[BobbyBreeze]

2jz on throttles in this would be the tits.

Log manifold ITB FTW.

[KKtrips]

Log Manifold with 6 butterflys is indeed the way of the future/past

[R100]

Cheers Spencer and Mikuni. Some real helpfull info there. Alot of work would be put into fabricating a 6 throttle manifold to make it look nice. After reading what you have said i am having second thoughts now. No point going down the same road you have only to end up with the same result. Will think on this for a while.. 3x twin throat sidedrafts would do the trick But for the cost, time and effort its not worth it.

[mikuni]

For me, carbing is always the other option to be considered, especially into a carburetted car already, because it saves mucking around putting a high pressure fuel system in, with a return. Its not a huge difficulty, but just another thing to take into consideration.

3 x any carb for a car will instantly blow things out of the water and I think you'd find that the expense to put dellortos or webbers on would out weight the cost for an aftermarket ecu anyway. Combine that with carb rebuild and rejetting costs, which aren't applicable with FI and also the difficulty to tune carbs in comparison to FI.

Cheapest option would be bike carbs, but this introduces other issues, especially for a big capacity straight 6, as it would need a lot of air/fuel.

Next problem is spark. Might end up needing an ecu just for ignition, or a big ugly old dizzy on there thats less than ideal.

Just keep it factory? Boring