Big Boost Turbo - Stock Motor & Fueling

[2053.media]

Hello! I'm new to this forum and I wanted to see if anyone had any questions relating to the Big Boost big turbo kit for the Fiesta ST. I've been running it for about 5 months and I have not had any issues relating to the turbo. The car performs very well but the boost lag is extremely noticeable. I'm usually at about 12-15psi by 4,000 RPM... Most of the power from this turbo is near redline but I've gotten used to it. Asides from that, this turbo provides a lot of power for a fairly good price!

I wanted to make this post to get out there and try to answer any questions people may have about this turbo kit since I can't find any other people running this kit.

 

[Stevesims]

Hello! I'm new to this forum and I wanted to see if anyone had any questions relating to the Big Boost big turbo kit for the Fiesta ST. I've been running it for about 5 months and I have not had any issues relating to the turbo. The car performs very well but the boost lag is extremely noticeable. I'm usually at about 12-15psi by 4,000 RPM... Most of the power from this turbo is near redline but I've gotten used to it. Asides from that, this turbo provides a lot of power for a fairly good price!

I wanted to make this post to get out there and try to answer any questions people may have about this turbo kit since I can't find any other people running this kit.

Which turbo are you running? I am looking to upgrade by 2560 and Pumaspeed manifold and am leaning towards the S280. Curious what you have and any other supporting mods with it.

 

[2053.media]

Which turbo are you running? I am looking to upgrade by 2560 and Pumaspeed manifold and am leaning towards the S280. Curious what you have and any other supporting mods with it.

https://bigboostturbo.com/products/bigboost-stage-3-fiesta-st-turbo-kit

This is the exact turbo kit I’m running. I have a itg crossover pipe, ram air intake, whoosh intercooler, HKS BOV, whoosh rear motor mount and a radium PCV catch can. The kit comes with a catless downpipe too. Everything has been holding up great and it’s a very fun option. Also, the kit works with a stock intake system and intercooler.

 

[Mega ST]

I couldn't do a laggy setup on this platform. The low end torque is what makes it fun to me. If I have to wait until 4K rpm for some decent boost she better rev to at least 8K rpm and be making north of 600whp. To each his own of course.

 

[dhminer]

I couldn't do a laggy setup on this platform. The low end torque is what makes it fun to me. If I have to wait until 4K rpm for some decent boost she better rev to at least 8K rpm and be making north of 600whp. To each his own of course.

If you’re revving it out to 7200 or 7500 on a big turbo, as long as boost comes on by 4k you’re never really dropping out of the powerband. This turbo seems like it’s at least as laggy as the 2860 though if not more so

 

[2053.media]

If you’re revving it out to 7200 or 7500 on a big turbo, as long as boost comes on by 4k you’re never really dropping out of the powerband. This turbo seems like it’s at least as laggy as the 2860 though if not more so

The only time I’ve had it drop out on me is on 2nd-3rd shifts. If I don’t rev it all the way out it won’t have enough rpm in 3rd to get back into boost. Then again I haven’t messed around with flat foot shifting yet.

 

[Traceman]

Hello! I'm new to this forum and I wanted to see if anyone had any questions relating to the Big Boost big turbo kit for the Fiesta ST. I've been running it for about 5 months and I have not had any issues relating to the turbo. The car performs very well but the boost lag is extremely noticeable. I'm usually at about 12-15psi by 4,000 RPM... Most of the power from this turbo is near redline but I've gotten used to it. Asides from that, this turbo provides a lot of power for a fairly good price!

I wanted to make this post to get out there and try to answer any questions people may have about this turbo kit since I can't find any other people running this kit.

What kind of power are you making with stock fuel system

 

[dhminer]

What kind of power are you making with stock fuel system

All big turbos make the same power on stock fuel, just different power bands. Hybrids are the only aftermarket that may not max out the stock fuel system (some of them do, though).

275-285whp on 93
290-300whp on Ethanol blends

 

[Traceman]

All big turbos make the same power on stock fuel, just different power bands. Hybrids are the only aftermarket that may not max out the stock fuel system (some of them do, though).

275-285whp on 93
290-300whp on Ethanol blends

I’m just curious because in their yt video of their car it made 411 hp with 4 port aux which is kinda fire but I haven’t seen any other people with 4 port just 2 port but just kinda wanna see more videos of the big boost kit

 

[dhminer]

I’m just curious because in their yt video of their car it made 411 hp with 4 port aux which is kinda fire but I haven’t seen any other people with 4 port just 2 port but just kinda wanna see more videos of the big boost kit

Tons of folks on here running 4 port aux amigo.

 

[Traceman]

Tons of folks on here running 4 port aux amigo.

Sorry my bad I meant videos of yt running 4 port aux

 

[2053.media]

What kind of power are you making with stock fuel system

I haven't had it on a dyno or anything but I would say around 300whp. I'm not running E30 nor will I with the current fuel setup because there wouldn't be any gains since the fuel system is completely maxxed out as is

 

[Traceman]

I haven't had it on a dyno or anything but I would say around 300whp. I'm not running E30 nor will I with the current fuel setup because there wouldn't be any gains since the fuel system is completely maxxed out as is

You got any videos with this turbo I’d love to see some pulls

 

[2053.media]

You got any videos with this turbo I’d love to see some pulls

I'll get some tonight, I just got my 2JRacing intake delivered so i'm going to install that and get some vids after.

 

[Traceman]

Y

I'll get some tonight, I just got my 2JRacing intake delivered so i'm going to install that and get some vids after.

you got a yt channel or something I can look for

 

[2053.media]

Y
you got a yt channel or something I can look for

No, sorry. I've been super busy recently and I haven't really had time to get a good video. I'll try to get one soon tho.

 

[scooter123]

I have to wonder how long it will be before the cast pistons in your stock motor let go. Yeah, that will happen. I suggest you get a Mountune long block to keep in your garage for when the stock motor blows up. BTW, the primary cause is the revs. Ford didn't design these engines with a lot of reserve strength and running past 6 grand is overstressing the pistons. In addition modern DI turbo motors are notorious for holing a piston quickly in a fuel starvation event. IMO when you are looking to really boost your power you need to start with a Mountune MRX long block, get a larger radiator, install a Meth system, and increase the fuel capacity to match the hihger fuel requirements of the new engine.

 

[Traceman]

No, sorry. I've been super busy recently and I haven't really had time to get a good video. I'll try to get one soon tho.

No rush man kinda funny thou I basically was planning on the same setup as you cowl intake with the big boost kit but I’d wanna go 4 port

 

[dhminer]

I have to wonder how long it will be before the cast pistons in your stock motor let go. Yeah, that will happen. I suggest you get a Mountune long block to keep in your garage for when the stock motor blows up. BTW, the primary cause is the revs. Ford didn't design these engines with a lot of reserve strength and running past 6 grand is overstressing the pistons. In addition modern DI turbo motors are notorious for holing a piston quickly in a fuel starvation event. IMO when you are looking to really boost your power you need to start with a Mountune MRX long block, get a larger radiator, install a Meth system, and increase the fuel capacity to match the hihger fuel requirements of the new engine.

Lot of misinformation in this post. This engine has proven highly reliable at 300whp with 7k rpm redlines. Evidence everywhere on this forum. The issues seem to come into play in excess of 350whp but that’s still mostly transmission issues we’ve seen

 

[scooter123]

Over the years we have seen many posts concerning blown engines on this forum. Causes are usually holed pistons, cylinders splitting at the top in that crack between cylinders (a problem Ford has acknowledged and redesigned the 2022 Escape motor for), and the base of the cylinders separating from the crankcase. In almost all cases a larger turbo was in use. For this poster the only thing limiting his engine from approaching 400 WHP is the fuel system and that is not a good method for limiting the power, because it's only a small hiccup away from a lean combustion event. Just one tiny little bit of junk in the ejector can result in a piston with a gaping hole in it. It's one reason why he should have a Meth system in place because they can provide a bit of protection from a lean combustion event.

As for my advice about limiting engine speed, it's real simple. If you enjoy getting a new engine every 15 to 20K miles go ahead and rev the snot out if it. If you want an engine to last for 10 or 15 YEARS, then limit the engine speed to that put in place by Ford.

Seriously the OP now has two choices. One is to go to an engine with forged pistons, premium connecting rods, and a carefully inspected and balanced crankshaft so he can increase the capacity of the fuel system and take full advantage of that Big Turbo. Or step down to one of the hybrid turbos capable of producing 280-300 WHP with the stock fuel system in balance with the output. Personally I would go with the smaller turbo, once you break that 400 HP threshold it really gets expensive. By the time you strengthen the Fiesta to work well with 400+ HP you'll have spent enough to purchase a used Focus RS Rally car in operating condition.