7A block transplant need ECU reflash or piggy?

[NA_Lover]

I'm about to dive in to my first 7A mod.
My engine is currently a 4A 20V BT auto...

The ori settings for 4A might not provide sufficient fuel to the engine rite..
Just wondering if I need to do anything to the ECU?
And if so.. whats the most budget conscious way to go about it?

 

[normality78]

I dont think so. As the power hike figure is not much hence im very sure your injector will be fine. But of course if you do have kind of piggyback will be better result

 

[azuaneman]

what injector that u'll using bro?
if using std 20v, i thinks it might be suitable 4u to go for upgrade ...
after that u can manage well using piggy ... control fuel lean / rich at different RPM ..

ECU flash might be not 100% working perfect.. unless u do a study research...
but for me, flashing ECU not much worth...
later on if u hv some upgrade, it would be different already ...

unless u go for Stand Alone, it would be different story ...

you may ask the sifu, some of them know well & some of them r using 7A mod already


* correct me if i'm wrong, just a newbie ... thanks

 

[NA_Lover]

Hmm.. I'll be using the stock fueling system..

I heard from taiko EG9 in another thread tat if I could manage with stock ECU if I just increased the fuel pressure till I get the desired AFR..

I'll need an adjustable fuel pressure regulator for this rite?

 

[azuaneman]

Hmm.. I'll be using the stock fueling system..

I heard from taiko EG9 in another thread tat if I could manage with stock ECU if I just increased the fuel pressure till I get the desired AFR..

I'll need an adjustable fuel pressure regulator for this rite?

increase fuel pressure will also increase the performance, for fueling system ..
just make sure your fuel pump good enuf to use AFR, if not it will heat up ur fuel pump ...
i think then current standard internal 20v fuel pump already 7 bar full, if not mistaken la ...

but i did prefer u go for piggy back also, simple 5 button afc might be ok.. :)
why not u face with the taiko EG9, maybe he can gv help some ...

 

[NA_Lover]

Wow.. this is more complicated then I thought...
Really must do more research on AFR and Fuel Pressure...

 

[normality78]

basically if you're just bolting on 7a block, i seriously dun see issue utilising stock fuel system but as AFR is a wise move.

 

[EG9]

put it in this way. 20V stock ecu will still provide proper AFR to 7AGE and it won't cause any problem to your engine, the stock injector which is about 290cc is still manage to provide more then enough fueling for NA engine.
You'll get the additional torque from the increament of engine capacity but not necessary you'll get the higher HP figure comparing on stock 20V blacktop engine because 20V blacktop have slightly peak power due to more balance rotation mass.
Overall you'll feel the power has increase on 7A bloack because of the additional torque. If you continue to run on auto tranny, the power increament is even more visible.

BUT if you want additional power, then you'll need something that can manage the fuel and ignition of your engine but not necessary if you already satisfied with the stock ecu +7A block setup. As normal, you'll alway get "poison" from other members and friends. hehe
Alway remember what is the purpose of the build up.

 

[NA_Lover]

Thanks a lot for the ideas taiko EG9.

Its a comforting because I was thinking of refaining from the piggy first..
Just worried earlier that after the 7A transplant suddenly discover tat my car would be in terrible condition because of insufficient fueling..

Oh.. one more question though.. I'm unsure if I should reuse the BT high comp pistons or just use the pistons from the 7A block...

After getting a ride in my friends car with 7A mod with BT piston.. Seems that the engine produces some worrying knocking..

Any thoughts?

 

[normality78]

go with BT piston.

 

[EG9]

Thanks a lot for the ideas taiko EG9.

Its a comforting because I was thinking of refaining from the piggy first..
Just worried earlier that after the 7A transplant suddenly discover tat my car would be in terrible condition because of insufficient fueling..

Oh.. one more question though.. I'm unsure if I should reuse the BT high comp pistons or just use the pistons from the 7A block...

After getting a ride in my friends car with 7A mod with BT piston.. Seems that the engine produces some worrying knocking..

Any thoughts?

Piston?...this is very tricky part for 7AGE build. If you use original 7AFE piston, no power due to very low CR and it's defeat the purpose of the engine build. With Backtop piston, you need to use stock gasket which is about 1.1mm or 1.2mm, maybe you can try slightly ticker one and try to avoid using 7AFE gasket because it's only 0.5mm and it's too thin and the CR will be more then 11:1.
With high CR in 7AGE, you'll lose top end power, it mean your max power will be at 6.8K or 7K compared to the stock 20V which is some where 7.5K -8.5K RPM.
If you're able to look for slightly lower compression pistons compared to the Blacktop 20V is even better, but u need to make sure it will clear the valves from the 4AGE 20V. The middle valve of the intake valve is the one that need more clearance.
My advice is stick with 20V BT piston with thicker gasket.

 

[20V Quard Cam]

i m BT auto oso..just wondering if i use Dastek Unichip will increase the response or not. Or just not so much different.

 

[EG9]

As long as you can alter the fuel mapping at some certain RPM range and the ignition timing properly, the respond will increase.

 

[NA_Lover]

Piston?...this is very tricky part for 7AGE build. If you use original 7AFE piston, no power due to very low CR and it's defeat the purpose of the engine build. With Backtop piston, you need to use stock gasket which is about 1.1mm or 1.2mm, maybe you can try slightly ticker one and try to avoid using 7AFE gasket because it's only 0.5mm and it's too thin and the CR will be more then 11:1.
With high CR in 7AGE, you'll lose top end power, it mean your max power will be at 6.8K or 7K compared to the stock 20V which is some where 7.5K -8.5K RPM.
If you're able to look for slightly lower compression pistons compared to the Blacktop 20V is even better, but u need to make sure it will clear the valves from the 4AGE 20V. The middle valve of the intake valve is the one that need more clearance.
My advice is stick with 20V BT piston with thicker gasket.

Wow.. I'm really learning a lot here.
Gasket thickness to balance out the compression ratio..

But just wondering.. is it possible to use twin layers to increase the thickness?
Anyways.. I'm just going for the build because my BT is really underpowered for my car weight... dragging along oni.. so really need the extra torque..