turbo and carby questions

[81pw]

im run a turbo tr efi setup atm it leans out all the time so i want to swap it to carby.
1st question wat is a good carby to use for blowthough setup. i read ppl use 32/34 webers but the might leak under boost and i dont really wana put it in a pressureised box.
2nd question can i use a 2.0 turbo dizzy on a 2.6l
cheers.

[Cottees]

If you have the EFI and Turbo set up, why not just mod the EFI to stop leaning out? Are you using a stock ECU? If you are, that is why it is leaning out. Why not try an after market ECU?

[81pw]

Yea it's got the stock ecu. I've been quoted about 4000 for a after market computer and tune, don't really have that kinda of money atm. But if I can get a blow though set up for less then 1000 that's more in my price range.

[turbosigma]

Old Microtech for the win.

Just be sure its setup for a 4 cylinder. eg, if its for an sr20 - you will have to use all sr20 sensors air/water/timing etc.
Don't get one setup for a 6 or rotar - would need to be sent back to Microtech to change config. And you can only send LT's not MT's for a re-config (MT's to old).

[DanTurboLancer]

You wont get a Blow through carb set up and tuned properly for $1000.
It would only be a backward step from what you have now.

How much boost are you running?

Back the boost right off,
Play with your timing to get it running nice aslong as its not leaning off or pinging, and be happy with it until you can afford an after market Computer.

Microtech is a cheap option.
But i would advise a computer with closed loop, it has lower emissions output.
Easier to get passed for engineering.

Unless you can do alot of it yourself,
$4000 is about what you would expect to pay

[LEE]

ok I will put in my two cents , this should help you out,
find an apexi afc
run 450cc injectors (modified falcon ones do the trick Tuff car parts do them for 200 a set) cut the groove with a hacksaw for the clip
1.9 to 1 malpassi fuel reg
set fuel pressure at 35psi , use wide band to set apexi below 25% throttle
use a hob switch set at 4psi that will change the fuel pressure reg from vacuum from the booster side of the vac one way valve to manifold pressure via a 3 way vacuum switch
I run 12 psi and light up 255/50 with ease and have a AF at WOT of 11 to 1 , its rich but all up it cost me 400 bucks in parts I cant complain If i set it up to run 6psi and use 330 cc injectors its ultra smooth and cheap to run with a AF at WOT of 13 to 1 a tad lean but doesnt ping and the plugs look good when base timing set at 2 deg and thats without hobs and vac switch fuel at 43psi , but honestly you can get an Adaptronic ecu fitted and tuned for 2500 and it has the same functions as a MOTEC, autronic and haltec without the blown out price tags and full back up made in Australia

[HEMI26]

hey im just putting out there (mod/admin u can delete if u dont like) i just rebuilt my friends 304 top half with some good's and used blue tops when it the computer was tuned for black tops and it was runnin way to rich so i had to put the smaller injectors back in (the black tops) and it went great after that,

and a dck head tuner tuned my friends r31t with a micro tech wrong , its running rich at idile (fowling out plugs) and good in the high rev range after 2.7/3k,

and also do blue tops flow more than yellow tops as there all used in the holdens yellow tops were used in the vn grpa 304, blue tops in the 355s, and vt 355's used diff injectors aswell, also u can use ls1 injectors in 304/355 builds but im unsure if there the same size or bigger than the blue tops,

im just woundering if the magna ecu will run a little richer with bigger injectors, what injectors are u running blue tops yellow tops,

just putting it up as it might be a cheap way to help a little with the stock magna ecu when its on boost with the timing, Spark plugs n stuff are done right and a little tune (most places cost about $200 for a 304 tune, timing etc on the dyno with a stock computer)

as im goin blo thro aswell untill i have the $$$ for the after market ecu, but i can see my self trying this some time later this year lol and see how i go as i got more than enuff parts to do it

just my cents anyway

[leoca]

Just something you could try disconnecting your airflow meter and letting us know if it improves ,maybe fuel economy will be out the window/....Also yes I agree with hemi ...upsizing your fuel injectors should improve the situation.

What does your fuel system consist of?.

[HEMI26]

just another spanner in the work im new to the sigi turbo engine but as far as i know there is a relay to tern the 2nd fuel pump on when it hits boost corect me if im wrong please

if so can u run extra injectors that tern on with the relay some how? as i know with micro tech u can run 2 injectors of the same out put to them

which has givin me an idea for a set up in the future

[LEE]

thats the whole idea with the hobs switch , it changes the fuel reg from vac to boost but at the point when it starts to lean out ,same as the sigma turbo. beige tops and blue top injectors are 275 at 45psi , xr6 are 300 at 45 psi early commodores are rated at 260 , modified xr6(42lb) are 450 at 45 psi , the ev 6 style injector has 4 holes and atomises better than the single squirter ev1,the problem with the std ecu/inj set up can handle up to 4psi , then leans out badly thats why i ran a rising rate 2 to 1 reg but found its only good to 6 psi with 300cc injectors, when you use the same set up but with bigger injectors soon as the afm hits max reading(2psi) it will dump max fuel and cause it to stumble badly, you need a way of trimming back the fuel thats why I used the hob switch and a 3 way vac valve to give max fuel another 2psi above max reading that stops the stumble it will be rich up to 12psi but its driveable ,and torquey, the only hick up it gets is when you release throttle and it gives a small hunt on the down rev, but running big injectors you need to control the lower rpm settings so I used an apexi safc, pick them up these days for 100 bucks 2nd hand, these are easy to wire in ( just realised i could use vtec output to control vac switch , Damn)

[leoca]

...so whats going on 81pw...try those things I recommended yet mate?

[HEMI26]

...so whats going on 81pw...try those things I recommended yet mate?

cheers for that lee

???? im going to

[81pw]

That's for the advice mate I'll put bigger injectors in and a wideband sensor in to see how it goes. I've seen some guy on a magna putting 4 more injectors into the plenum champer running a piggyback ecu to run them when it hits boost. I've been ringing alot of tuning places they all say go with stand alone. Cheapest I've got was 2400 for install and tune. So I might try saving for that. I'm only running 6 psi ATM so I'll put the bigger injectors in to get me through till I go aftermarket. Where can I buy apexi afc? Cheers boys

[MitsiMitch]

hey im just putting out there (mod/admin u can delete if u dont like) i just rebuilt my friends 304 top half with some good's and used blue tops when it the computer was tuned for black tops and it was runnin way to rich so i had to put the smaller injectors back in (the black tops) and it went great after that,

and a dck head tuner tuned my friends r31t with a micro tech wrong , its running rich at idile (fowling out plugs) and good in the high rev range after 2.7/3k,

and also do blue tops flow more than yellow tops as there all used in the holdens yellow tops were used in the vn grpa 304, blue tops in the 355s, and vt 355's used diff injectors aswell, also u can use ls1 injectors in 304/355 builds but im unsure if there the same size or bigger than the blue tops,

im just woundering if the magna ecu will run a little richer with bigger injectors, what injectors are u running blue tops yellow tops,

just putting it up as it might be a cheap way to help a little with the stock magna ecu when its on boost with the timing, Spark plugs n stuff are done right and a little tune (most places cost about $200 for a 304 tune, timing etc on the dyno with a stock computer)

as im goin blo thro aswell untill i have the $$$ for the after market ecu, but i can see my self trying this some time later this year lol and see how i go as i got more than enuff parts to do it

just my cents anyway

lot of things to do mate...

Where to buy apexi afc? ..try to visit this site..http://www.alamomotorsports.com/apexi/safc.html or http://motors.shop.ebay.com/i.html?_nkw=apexi+afc ...i know you already aware of this site..just suggesting..

[HEMI26]

cheers for that mitsimitch

just another spanner in the work im new to the sigi turbo engine but as far as i know there is a relay to tern the 2nd fuel pump on when it hits boost corect me if im wrong please

if so can u run extra injectors that tern on with a relay brigged into the loom some how? as i know with micro tech u can run 2 injectors of the same out put to them

Dave Mitchell

ps i wired the micro tech in my friends rb30t r31

[DanTurboLancer]

That's for the advice mate I'll put bigger injectors in and a wideband sensor in to see how it goes. I've seen some guy on a magna putting 4 more injectors into the plenum champer running a piggyback ecu to run them when it hits boost. I've been ringing alot of tuning places they all say go with stand alone. Cheapest I've got was 2400 for install and tune.

Just be careful with the 'Cheapest' option,
they may not know what they are doing and blow it up on you.

Also double check as i fell for this one.
They quoted me a price for install and tune.

What they meant was a basic tune just to get it running.

A proper full tune is extra!


Also do you need to upgrade your fuel system?
BTW in N.S.W adjustable fuel pressure regulators are not legal.
I am going through this with the EPA at the moment

[TR11KY]

Yea it's got the stock ecu. I've been quoted about 4000 for a after market computer and tune, don't really have that kinda of money atm. But if I can get a blow though set up for less then 1000 that's more in my price range.

my adaptronic installed and dyno tuned cost me $1500 all up.

speak to adaptronic dealer and go from there mate, the ecu is around 1K with most basic sensors and tune is $350. Granted he also did other work for me like alarm and cooler piping plus added additional sensors for me.

[81pw]

just rang one of the adaptronic dealers and they said 2800-3200 for full install and tune. the cheapest i got so far was eculink g4 extreme ecu one of the dealers near me said 2200 full install and tune. ill just have to start saving more money never stops if u own a sigma lol. thanks for the help boys

[TR11KY]

looks like even adaptronics are goin up... they are well worth the spend mate