12-15 PSI on a 420A

[SoCalK61000]

Ok so I'm going turbo on the 420A and I need some advice.....I'm looking to run 12-15 psi of boost and this is what I got so far

Eagle rods
Weisco pistons 8.5:1
Ported head
Crower turbo cams
FMU
Dual springs w/ ti retainers
SS valves
Turbo mani
T3T4 turbo
Safc
Bov
Wastegate
6 puck clutch
Intercooler

What else will I need? I'm thinking,
Gates blue timing belt
Arp head studs
255 pump
Wideband
Fuel pressure gauge?
Bigger injectors? What size can I use with the safc?
Ms? Do I need it @ only 12ish psi

Any and all help is apreciated I wanna get the rest of the parts I need so I can get this thing boosted

 

[Fotowntalon]

why such low compression pistons?

 

[96 420a-t]

What rate fmu? The injectors may become an issue.

I ran 275cc in place of my stock 190's and my safc was at 24% to get my fuel trims in line so i think roughly 350cc would be about pushing it.

Also what rate fmu are you pooking at?

Side. Note if you are putting this much work into this car why not just go megasquirt?

 

[99gst_racer]

lbs ≠ PSI

'lbs' is weight. 'PSI' is pressure per volume. I hate to nitpick, but it's worth saying right.

 

[Diamond Star Werks]

why such low compression pistons?

Low compression? 8.5 is standard on 2g turbo engines. If he's turboing that isn't bad.

 

[SoCalK61000]

What rate fmu? The injectors may become an issue.

I ran 275cc in place of my stock 190's and my safc was at 24% to get my fuel trims in line so i think roughly 350cc would be about pushing it.

Also what rate fmu are you pooking at?

Side. Note if you are putting this much work into this car why not just go megasquirt?

I believe its a 12:1 fmu honestly I'm not sure tho, I've been looking at the sfmu as well. I'm debating on going with Ms but if I don't have to id rather not, unless it turns out to be more cost effective that way. And I've heard that with Ms its hard to get the the stock iac to work and the gauges in the dash are a pita to get working right as well

 

[Fotowntalon]

Low compression? 8.5 is standard on 2g turbo engines. If he's turboing that isn't bad.

True, but he is turboing a 420a, which stock CR is 9.6, and can handle 10psi on a stock block, I just don't see the point of dropping CR unless he is going to pushing a lot more than 12 psi.

 

[SoCalK61000]

True, but he is turboing a 420a, which stock CR is 9.6, and can handle 10psi on a stock block, I just don't see the point of dropping CR unless he is going to pushing a lot more than 12 psi.

Becouse unless you have custom pistons made that's the compression ratio they come in.

lbs ≠ PSI

'lbs' is weight. 'PSI' is pressure per volume. I hate to nitpick, but it's worth saying right.

Your right, can you change the title for me please?

 

[Fotowntalon]

Wiseco makes an 8.8, you could also get away with a 10.5 with that low of boost if you tune properly.

 

[Slo2gen]

Yep, off the shelf pistons are 8.8, 10.5 and 12.5:1 for the 420a. The biggest i think I remember someone running on a SFMU and SAFC(which was a WHILE back) was 550cc injectors. With an FMU you are limited to what you can run as far as injector size. Your list is right for what you need extra and you need to add either a missing link or FCD.

 

[bryanwheat]

Wiseco makes an 8.8, you could also get away with a 10.5 with that low of boost if you tune properly.

Running a 10.5:1 engine with boost on pump gas and stock timing maps is just asking for detonation. Even running the engine n/a with that much compression will detonate like crazy on pump gas and stock maps. The 8.5's will allow for more power on pump gas and stock timing maps.

 

[bullettdsm]

Running a 10.5:1 engine with boost on pump gas and stock timing maps is just asking for detonation. Even running the engine n/a with that much compression will detonate like crazy on pump gas and stock maps. The 8.5's will allow for more power on pump gas and stock timing maps.

This is not true. Sorry, its been proven repeatedly. I also believe that you can run NA on 12.5 comp, on stock ECU. If I could get my Crane 28's to work properly, I could have already tested it. Unfortunately (like everything else race car related lately), they are giving me a hard time

MB

 

[scottyhops]

i wish our car had more tuning abilities, i have the hahn port fueler, no one know anything about it, megasquirt is the best, and people know how to tune them at shops

 

[SoCalK61000]

Yep, off the shelf pistons are 8.8, 10.5 and 12.5:1 for the 420a. The biggest i think I remember someone running on a SFMU and SAFC(which was a WHILE back) was 550cc injectors. With an FMU you are limited to what you can run as far as injector size. Your list is right for what you need extra and you need to add either a missing link or FCD.

yeah sorry the pistons are 8.8:1

And yeah the FM is killing me Im leaning towards running Ms BIG TIME, but I still think its overkill for a 12-15 psi set up....and with Ms i can see myself pushing more like 20-25 psi and i dont wanna .

And yeah a missing link i forgot about that one thank you

 

[Fotowntalon]

They could be 8.5:1 not 8.8:1 if there JE's. Just to throw that out there, if you really plan on eventually going to the 20+ psi range, than the lower compression would be a safer bet.

 

[Slo2gen]

A friend of mines car was built with 8.8:1 and standard build like yours, he made 210whp on a S16g with MSnS on 10psi. MS is great but it does require some effort on your part.

 

[CODE4]

to the OP - psi is not a measurement of power. You do not plan a build around a target psi level.

You need to examine your power goal and subsequently select a compressor map that suits your needs.

It is about lbs/min. NOT PSI.

 

[SoCalK61000]

to the OP - psi is not a measurement of power. You do not plan a build around a target psi level.

You need to examine your power goal and subsequently select a compressor map that suits your needs.

It is about lbs/min. NOT PSI.

im not planning the build based on what psi and that statement really only applies to selecting the turbo and your 100% correct.

the power goal is about 250-300hp @ 10psi for right now, just trying to get an idea of what everyone is running at this boost level so i dont buy things twice

 

[necrotopsy]

Personally....

I like the 8 injector setup. only tune for when you're in boost, and keep stock reliability and fuel maps for when you're not.

Not that i'm saying you should go buy an 8 injector setup, but this is just my option.

for the car in my sig, it had the 8. stock primaries and 60# secondaries (which is somewhere around 640cc if i remember right)

 

[Slo2gen]

Personally....

I like the 8 injector setup. only tune for when you're in boost, and keep stock reliability and fuel maps for when you're not.

Not that i'm saying you should go buy an 8 injector setup, but this is just my option.

for the car in my sig, it had the 8. stock primaries and 60# secondaries (which is somewhere around 640cc if i remember right)

The biggest thing about the 8 injector set up is that its easy. If you do go with MS you will most likely be able to get a better MPG out of the car than using the stock injector for out of boost driving. If you go with something like MS you can also switch to E85 or race fuel and have a better tune as well. I know you can use race gas(Q16 etc.) on the stock map but it will never run as well if you could adjust it out of boost.

 

[99 gs iowa]

defintly go with hahn portfueler, easy to soon, an get close to stock hp if you can stay out of boost

 

[HadesOmega]

I think you will be fine but the fuel system is going to be the problem. If your using the plain FMU your fuel pressures will be too high. You will need something like that (which I'm selling ) SFMU

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I was running the 30lb ford motorsports injectors with SFMU and running 10 psi. Could probably run 12. You could probably get to 15 psi if you bought some bigger injectors and lowered the base fuel pressure even more. with the 30lb injectors I was running 22psi FP already so you can go bigger. Then run a SAFC to fine tune it on a dyno.

Its crazy what you can do with tuning, on my GST I'm approaching 20psi and the car looks stockish still. I made 210WHP untuned with my 420A, I'm sure if you do some dyno tuning you can get it close to the 250HP area, if you go with bigger injectors and and up it to 12ish psi you should be good. Its sad the turbos we're using on these 420A are seeing just a fraction of their true potential though, but I love the weight balance and handling of the 2GNTs.

 

[GSTurbo1]

I'm running everything you are on 15 psi. It's stout, check out everything I have done to mine. I'm running 8.8:1 ratio, I need to replace my valve stem seals... head keeps pressurizing

A friend of mines car was built with 8.8:1 and standard build like yours, he made 210whp on a S16g with MSnS on 10psi. MS is great but it does require some effort on your part.

Would that be my car? Dyno on 5psi was 233 whp, i'm running it on fifteen so closer to three hundred.