bigjay01cobra

Ok here is the update with all info on block cams and everything.

BLOCK
Balanced and Blueprinted 5.1L Stroker
3.750in Stroke, 6.000 Rod
11 to 1 Compression
All Forged

HEADS
01 Cobra Head shaved .010
5 angle valve job
Small amount of hand porting
New Spring and Retainers

CAMS
Comp Cams
Intake
DUR. 234 @.050
Valve Lift .475
@ 112.0 centerline

Exhaust
DUR. 232 @.050
Valve Lift .450
@ 116.0 Centerline


Ignition
Stock
NGK TR6 plugs

INTAKE
K&N Cold Air Intake
BBK Throttle Body
Stock 01 Cobra Intake

EXHAUST
BBK Ceramic Coated Longtubes
BBK off road X-pipe
Flowmaster Cat-back

TUNING
Tuned on dynojet using sniper tuning software
Total Timing set to 26 degrees

DYNO NUMBERS
316rwhp @ 6300rpm
293.85 tq @ 5300rpm
Air Fuel Ratio 13.0-13.3 throughout pull
Curve is nice and flat not bumps just a steady increase to 6300 stays level till 6500 then starts to drop.


The car was broke in on the dyno. To set intial tune, no full throttle pull. The car was driven for approxiately 150-200 miles. It then was strapped to dyno for pulls car put down 309 with 22 degrees of total timing. Car was driven for about 100 more miles then retuned again putting down 310. Finally after driving car another 100 miles timing was up to 26 and the car put down 316.

The car doesnt smoke at all not, no leaks, no nothing.

Ok I just picked up the car. I am going to drive it for a week or so then bring it back for more tuning or whatever. The cars has a very noticeable cam in it. I mean the thing shakes likes crazy.

Currently the cars likes to die at lights on occasion, and the CAI sucks some much air it sounds like I have a turbo on it.

To me the cars runs a little rough, but I was told that was due to the cams.

By my seat of the pants measures, it doesn't feel as good as it did before. Before from a roll at ~15mph I could nail it and it would roast the tires and when I would hit second it would roast them again. Now at 15mph it doesn't spin at all and shifting to second yeilds a small chirp.


Just doesnt make sense that the car would not make more power. Most people with the similar setups make at least 335 where as most are above 350.

I dont see how it is possible to have only gained about 50 hp over stock with all the mods. Just the exhaust and intake should have put me there.

Anyway, any and all help is greatly appreciated.

mfj

Dude. What kind of DA is your car being dynoed in? That could be 100% of the difference. Typically, in the summer heat, it's harder to peel out because the engine is producing less power AND the rubber of the tire sticks a lot better when the ashpalt is soldering hot...
Get it redynod in the winter and see what happens...

bigjay01cobra

I calculated DA to 2900ft that day.

MFJ you have comp stage 3's right. Does you car cam really hard? Mine shakes allot.
Can you feel the cams at all rpms almost like the car is running rough?

This is my first cammed car so I don't know how it is supposed to feel.

Thanks
Jason

P.S.I.cho

even with cams if your car isnt ideling you have a poor tune, they either need to bump your idle up to 900-1,000 rpm or figure out why it wont idle IAC, TPS etc..but i hate to brake it to you the 5.1L motor isnt a HUGE advantage over stock we have noticed minimal gains on turbo and supercharged setups from a 5.1 from stock, the advantage you get with the built motor is durability and the option to run more boost safely. your car might be showing these signs.

bigjay01cobra

But I went with 11 to 1 compression. Isnt that a little high for boost.

Can I run boost on that? If so how much?

Because I am very disappointed in this build, I dropped 9 grand on this build and lost power doesn't make much sense. But If i can turbo it later on it might be worth it.

I had planned on a 150+ shot of nitrous, but I would like boost even better.

The thing I dont understand is I had the heads redone with cams and a better exhaust. So that should have jumped it quite a bit.

Anyway I am going for a retune next week, and I am going to the local 1/8th mile drag friday to see what she runs. Before when I broke my tranny, I ran a 8.96 @ 83 spinning in every gear. It could have easily ran 8.4-5s, the previous owner had it in low 13s. So I hope I at least get back to that. But you never know.

Jason

P.S.I.cho

no i was just saying boost as a comparison, 11:1 motor might like some nitrous tho

bigjay01cobra

To update info. I went to the dragstrip last night. Car ran 9.03@ 78.69mph with quite a bit of tire spin. The funny thing was a 99 Cobra with exhaust, CAI, and tune was running the same times as me, with the sametire spinning problem. That time corressponds to a 14 flat 1/4 mile time. LMAO. I was launching at 3500 slipping the clutch trying to get traction. Shifted at 6800 with wheel hop and tire spin going into second.

Fobra

Yeah, I just dont know what you thought was going to happen, you need to know what cfm the heads are flowing to gauge your gain, the 5.1 is going to do next to nothing for you... maybe +20, other than that seems like you just got better hardware. The good news is that your good to go for some happy gas.

bigjay01cobra

I also got cams, longtubes, offroad xpipe, those alone will give it a substansial increase in power.

So far those things net me no gain. So you are trying to tell me those mods wouldn't give me any power.

Like I stated before the car put down 320 before adding above items.

P.S.I.cho

he is saying what i was saying earliar in your post, your mods or worth very little on a built car, cams can only do so much if the heads and intake wont flow air in. when i built my 5.0 to 331 stroker i used stock intake manifold the first pass and ran 14.2 1/4 mile, i switched to a trick flow track heat-R and ran 13.3. perfect example of CFM airflow restriction