rthackwray79

C5 rear mount turbo question?
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I have a 1998 C5 corvette with 232/234-112 lsa futral f14 camshaft,low lift..I believe 585 lift on each side.The car is 4l60 with Circle D 3600 stall and 3.90 geared.I recently added a rear mount 76mm turbocharger with intercooler.I am using stock manifolds with vbands welded on and entire turbo build is fabricated.My heads are stock and unmolested.I believe 806 castings but do have the valvetrain upgraded with dual springs,etc.Intake is a stock ls1 and TB is a bbk 85mm with spacer..My question is..Will I be able to achieve over 550 rwhp with this combo and rev it to 6k even with the positive overlap of the camshaft?My car is at the tuners at the moment..The car is dropping off drastically on power @ 5k rpm at only 5lbs of boost.The fueling,afr, and pressures are ideal as my tuner tells me.Any and all info is appreciated.I just want my car to at least rev to 5700 before dropping off.I believe the cam is rated for 6500 rpm.Its being tuned on E85 and has walbro 450lph e85 pump with hotwire and siemens deka 80lb high impedence injectors.Thanks guys

rthackwray79

Somebody,anybody?

gtfoxy

What does your fuel system consist of?

What are the specs on the turbo system?

rthackwray79

The specs of fuel and turbo are in first post.

rthackwray79

76mm with .81ar exhaust..450lph e85 pump with hotwire and 80lb injectors.

gtfoxy

What are the specs on the turbine & piping size feeding it?

Are you data logging?

rthackwray79

3.0" single on exhaust going into turbo.Charge piping to intercooler is 2.5..After intercooler into the TB is 3.0

rthackwray79

I got pics but dont know how to share.

rthackwray79

And im not datalogging.Its at the tuners shop.

stevieturbo

Yes it should rev better that what you're suggesting it does at present. What does your tuner say, he has all the info to hand ?

Orr89rocz

iTrader: (13)

Valvetrain issue? What springs? They old? Plugs? Plug gap?

Junkie

Did you make any changes to the longblock since it ran well N/A? When did it drop off then?

rthackwray79

Im not sure on tuning and dont have details on parameters,etc.I have dual springs that support .650 lift,no float or issues there as far as I know.Plugs are new,br17's and spark is optimal.No changes to longblock.

rthackwray79

I wish I had more to tell you..I find it funny that power just drops off at 5k with that camshaft.I mean its not even in the meat of the peak powerband yet.

rthackwray79

Lots left on the table..Plus I want my car back.I miss her..lol

Forcefed86

iTrader: (4)

I don't see anything that should be limiting your ability to rev. What "76mm" turbo? Exh. housing size? exh wheel size?

Pop the turbo off and make a pull and see if the power drop "goes away".Or install a pressure gauge on the manifolds to measure back pressure levels.

Manifolds glowing during a pull? (Have him shut off the lights to look.)

Any flex joints in the system with braided material on the inside? like these?





Could one have come apart internally?



Did you do a pressure test on the cold side to ensure you have no leaks?

Import stuff... but the idea is the same...



Good luck!