StatoJase

Hi I am currently running a gt4776 (a diesel turbo) on my 408 l92 forged stroker, power level flat lined at 630rwhp and torque dropped sharply from 800ftlb at 3000rpm. Got told I am in blown head gasket territory running this turbo. So after saving up I have a gt5588 to fit now. Would like to know if the rest of my setup will keep up with the turbo swap and what I can expect.

80lb injectors running 58psi base 1to1 referenced aeromotive reg.
single a1000 pump -8 lines
cam is a small turbo cam around the 228 230 region.
twin 38mm turbosmart gates, 5" dump to twin 3.5" to twin 3" out the back.
Turbo 400 trans with 3000rpm converter
9" spooled diff with 3.25 ratio.
Currently tuned to 15 psi boost nice and safe low 11afr.
Eboost 2 for boost control
Also have an aem progressive meth injection kit fitted which I haven't tuned or set up fully yet running single nozzle 50/50 after intercooler.

Any info would be greatly appreciated.

StatoJase

Does anyone have any opinions on my set up? Basically I am looking to stay at same boost maybe 17psi, still run the ebay 4" intercooler, and the meth injection will be a safety margin rather than power source but I know the 5588 will be a lot more efficient and move a lot more air. Worried about the 80 lb injectors and pump flow. How much of a jump is this turbo going to give

Forcefed86

iTrader: (4)

It's not matched properly to your engine/cam IMO. Why buy a 1500hp big money turbo if your not going to be making that kind of power? Anything will make boost...but I think that will be a lag monster and a poor choice for your setup. You'd be much better off with a turbo matched to your engine/setup. Call up one of the turbo vendors on this site and they can suggest one for you. Forcedinductions.com would be a good place to look IMO.

StatoJase

It was one of the vendors that recommended the gt55 with the opinion that my gt47 would blow head gaskets and obviously choke my 408 forcefed. The reason I posted this was to find the holes in my setup and get some opinions so I can optimize my setup a bit better for this turbo. I have read the gt55 turbine recommended a fair bit for a 408, I did read a lot and asked a few of the vendors prior to buying.
I know i will probably not use this turbo to its full potential but it came up so here I am. I started off building the kit around a small wheel gt42. Hobby stuff.

Forcefed86

iTrader: (4)

What kind of power do you want and when do you want it? IMO it just seemed a little excessive and expensive for what sounds like a low rpm mild cam combo.

What size wheel and AR housing was on your GT47? I'd think something in the $900 S400SX-80 range would work well.

StatoJase

To be honest with u I guess it was built for more of a low rpm street monster. But things always end up evolving. The 47 was a second hand diesel turbo. With a 76/108 front and 84/92 rear with 1.32 turbine a/r. Probably could have gotten something like u mentioned but I kept getting told it was more the turbine I needed to step up. I have the 55 now and goal is 800 through the t400 and 9".

Forcefed86

iTrader: (4)

Any of the S480 series with the big 1.51AR would hit that goal and then some IMO. Also something seems odd with your power falling off that rapidly. Id put a gauge on your hotside and measure the actual back pressure. I bet its not as bad as u think. Can u turn the boost down and make power at higher rpm?

StatoJase

It really struggled making more grunt on dyno. Boost timing and fuel adjustments didn't do much.I did install fittings in my exhaust pre and post turbo for testing but I haven't tested as I had a pump fail on dyno luckily between runs. To me it looks like turbo runs out of legs. I have the 55 now as recommended, got it for a good price so it's going on. Back to original post 80 lb injectors get me to 800whp?

Forcefed86

iTrader: (4)

Very nice turbo don't get me wrong... Hope it works for ya. A 408 isn't that huge of a motor. A 1.32 84/92 wheel shouldn't be choking it at 3k IMO. Make sure to report back and let us know what happens.

You can pick up a cheap peak hold tire pressure gauge and plumb it into the exh for a back pressure reading. Works great on my rig. I needed to put a few copper coils and a fuel filter inline to keep soot and crap out of the gauge though. Been working for awhile now. I get the peak pressure reading after every pull "saved" on the gauge.

LT1PWRD

iTrader: (2)

You can pick up a cheap peak hold tire pressure gauge and plumb it into the exh for a back pressure reading. Works great on my rig. I needed to put a few copper coils and a fuel filter inline to keep soot and crap out of the gauge though. Been working for awhile now. I get the peak pressure reading after every pull "saved" on the gauge.[/QUOTE]

Such a great idea! Stealin that!