New to me 2.8 KB Cobra. What to expect?

[ScreamingMach46]

Ok, long story short, sold my bolt on 100 shot 04 Screaming Yellow Mach 1 and picked up a KB'd 04 Screaming Yellow Cobra with a dropped valve seat. Have the motor torn apart now and almost ready to go back together. Not sure what to expect or even exactly sure what boost it'll be making or what size belt to get.

Previous owner said it made 635rwhp with just the KB 2.8H w/ 3.75 pulley, JLT HB CAI, o/r x-pipe, catback and BAP on 16psi. That seems high to me for only 16psi but idk.

Mod List:
KB 2.8H w/ 3.75 Pulley
Metco 4lb Lower w/ matching Alt pulley
Billetflow Idler set (3-100mm 1-90mm)
98 Cobra Intake Cams
JLT HB CAI
SCT BA3000 MAF
BBK O/R X-pipe
Magnaflow Catback
D&D 26-spline input shaft
Promotion 750hp Clutch
Pro 5.0 Shifter
IRS Diff Cover/girdle
Welded FLSFCs
SLP Line Lock
Lethal Gen 2 Head Cooling Mod
170° Thermostat
60lb Injectors
Dual GT Pumps w/ dual FPDM harness
Might be missing some things but that should be the majority of the performance mods. Might add killer chiller if my nitrous kit sells soon.

So...
What kinda power should I be expecting on 93 octane?
How much boost should I see?
What size belt will I need?

Can NOT wait to get it running!

Thanks,
Joe

 

[jays03cobra]

All I can tell ya from the mods is that 635 on pump gas at 16 psi seems way high. No correction factor maybe? I'm at 22psi and was only able to put out 630 on pump gas. I honestly would love to know how people get some of there numbers. And I have headers, comp stage 2 cams,springs,pistons. Maybe my tuner sucked lol.

 

[jays03cobra]

I guess at this point I'd like to know what numbers I can expect when I retune the car Tuesday with the new sct xcal 3. I have every supporting mod needed to put up numbers. Not sure why I see guys numbers in the mid 600s running less than me.

 

[03GTGreen]

Theres no reason you shouldn't make at least 630 pushing 20/21#, be cautious with 93 and your tuner though, you need to go E85 or suck it up and run 100, check cobrabobs site for belt combo sizing chart

 

[SRT_2_SVT]

Numbers seem high but it'll make that on more boost. Expect it to spin.

/thread lol

 

[ScreamingMach46]

Theres no reason you shouldn't make at least 630 pushing 20/21#, be cautious with 93 and your tuner though, you need to go E85 or suck it up and run 100, check cobrabobs site for belt combo sizing chart

I might run a bit of 100 in there but have it tuned on 93. We'll see. Maybe if I get the direct hire position at work I'll be able to afford a return E85 setup this winter.

I'll check CobraBobs site meow.

 

[ScreamingMach46]

And yeah, I thought the numbers seemed really high since my buddies whipple 2.3 car made 592rwhp on 20psi. I'm hoping to be at the 630 mark with all the mods I've added.

 

[1S1K]

I guess at this point I'd like to know what numbers I can expect when I retune the car Tuesday with the new sct xcal 3. I have every supporting mod needed to put up numbers. Not sure why I see guys numbers in the mid 600s running less than me.

Jay, where are you getting your tune done? At 22lbs, your hp seems low. I just got a Metco 4lb lower kit and switching my upper pulley to 3.25. I should be around 22 or 23lbs and right around 675hp.

 

[ScreamingMach46]

So using CobraBob's site, it looks like 82.5" belt, that seem right?

 

[mp23]

I have a very very similar set up with the exception of stage 3 cams. I am hitting 635-650 on 18lbs on 93 octane.

 

[jays03cobra]

Jay, where are you getting your tune done? At 22lbs, your hp seems low. I just got a Metco 4lb lower kit and switching my upper pulley to 3.25. I should be around 22 or 23lbs and right around 675hp.

I'm having karls east coast do it. Currently I'm at 22psi which from all the threads I've read is too much on 93. So I'm looking to put it at 18-19. I'm wondering if the new tuner is going to work better. Last time this car was tuned was with an old sct tuner back in 04

 

[rudycobra]

2.8 behemoth here 672 on pump gas and 22 lbs
2 lb lower and 3.5 upper