1st Dyno run on my KB Cobra

Gixser · Nov 25, 2006

Well, Today I just did my first Dyno tune on a Dynojet Dyno, I was VERY happy with Keith the Guy that performed the work @ AZ Dyno Chip but I wasnt please with my cars output,

Mods- KB 2.1 with 8lb pulley, 42lb Injectors,255 walbro,MAC cold air intake,Shorty headers, SCT chip, BBK underdriver pulleys, and Spintech Side exhaust,Stock MAF(I have a Mafia and Lightning 90mm) but didnt need it with low output

Results, I am putting out 330 RWHP and 360RWT Not happy, All seems to go very well till 5200rpm then it drops off

My tuner is telling me its the Spintechs side system Does this sound rights?

I can see the boost gauge start slowly building more pressure once it hits 8lbs it slowly creeps up, Keith (My tuner) is telling me the back pressure is building,

I am running 2 1/2 exhaust with BBK crossover, into the Spintechs, I was think of doing cutouts in front of my spintechs. Any input will help thanks

I know I am ranting and jumping around but I just dropped 5k on 120 HP and it sucks

OrangeMustangGt · Nov 26, 2006

whell, i assume you have stock heads, cam, intake?

If you do, then you should be happy with that number....
i wouldent expect any more than that with the bottleneck heads.

That is actually about where you would be with a vortech also.

Don 95Vert · Nov 26, 2006

If it is does have stock heads and cam, consider that it would probably put down maybe 190-200. Then figure 15 RWHP for every pound of boost - roughly = 120. 120+200=320. Looks like you are right in the ballpark.

drakesdad · Nov 26, 2006

GreenMustangGt said:
whell, i assume you have stock heads, cam, intake?

If you do, then you should be happy with that number....
i wouldent expect any more than that with the bottleneck heads.

That is actually about where you would be with a vortech also.

Kyle, I was thinking th same thing........higher #'s than my HCI and supporting mods...............I'd be happy with these #'s

drakesdad · Nov 26, 2006

Don 95Vert said:
If it is does have stock heads and cam, consider that it would probably put down maybe 190-200. Then figure 15 RWHP for every pound of boost - roughly = 120. 120+200=320. Looks like you are right in the ballpark.

Don, I'm curious to see what you think about the comments about the exhaust........I know when I took off the factory H and went catless H it "felt" stronger..........I know we can "bottleneck" our motors.....whatcha think....

MattZ281LE · Nov 26, 2006

Ahhh yes....

If you are stock H/C/I those are very good #'s BE HAPPY

I made only 385/415 on my H/C/I KB 2.2 @ 8# But it was very driveable.

IMHO opinion the 2.2 is a bit oversized for the stock 302. Lots of bypassing and they build heat much faster if not moving alot of air.

tmoss · Nov 26, 2006

work that lower intake over - you'll get a nice hit even with stock heads.........I have a before-and-after dyno of a 1.8 on a stock combo on my website in the Photo folders of the Community Section. Instructions are on there on how to do it yourself too..........

Zero Signal · Nov 26, 2006

Maybe off topic, but is it a place you would go to again? I've been considering going there when my combo is all done becuase I've heard good things about those guys. I called them once and they seemed quite professional. OPnly catch is that I have a Tweecer.

Gixser · Nov 26, 2006

Thank guys, I feel abit better now, I am looking into AFR 165 heads right now not sure what cam yet,

I guess I just had bigger expectations,

droptopford 5 0 · Nov 29, 2006

you hafta think though... if you are thinking about aftermaket heads/ cam then you will be on the edge of splitting your block pretty easily, so i would be happy that you arent already putting down 400 rwhp becaus eheads would toast your motor... unless you also have plans for a new block in which case i take back my words. (yes i know many people put lots of power through stock blocks but i personally dont think its very reliable in many cases.)

Black95GTS · Nov 29, 2006

I'm pretty shocked that you are still using a stock maf at 330rw. I've never heard of the stock unit supporting that much HP, you must have pegged it out by now. If I were you, I'd be using that fancy LMAF you got there.

As far as power goes, I bet you have an awesome trq curve with that KB. But with Cobra heads and Intake, I think you could defiantely squeeze out more HP.

I'd take MAF voltage logs, I bet you'll see it peg.

Adam

4Jenna · Nov 29, 2006

Glad shes up and going bro, I agree on the #s also

Don 95Vert · Nov 29, 2006

drakesdad said:
Don, I'm curious to see what you think about the comments about the exhaust........I know when I took off the factory H and went catless H it "felt" stronger..........I know we can "bottleneck" our motors.....whatcha think....

I think the heads and intake are the bottleneck now. The exhaust system he has on it now is more show than go, but it's not the problem at this level.

Something else Gixser should consider, KB's on 5.0's have NEVER been great at making peak power. But take a look at your torque curve, then take a look at a stock torque curve - or even a torque curve from a centrifugal blown car making the same peak power. What you'll see is a HUGE increase in power under the curve - i.e. average power at any given RPM. That's what makes the car go down the track.

My Mustang when it had the KB 5.0 - with aluminum heads and most everything else (except for MAF/fuel) stock - only made 360 RWHP - BUT at a track weight of 3700# went 11.7. The same car with a cam and KB2200/Flowzilla ONLY made 405 RWHP, but went 11.1/123.

If you ARE running a stock MAF, you ARE pegging it - if it made that power on the dyno and was almost pegging it, then for sure on the street/track, it WILL peg it. Even if the tuner did a band-aid and used fuel adders in the tune, you'll eventually hurt something. A 90mm LMAF would work fine - but you'd need a retune.

Good Luck!
Don

AUcobra94 · Nov 29, 2006

I would look for a mechanical problem before I went out and bought heads or exhaust. First it should pull past 5200rpm. I think you should be making more power, my friends 94 lightning with the gt40 heads and intake went from 270 hp to 390 after his blower(centrifical @ 8psi). Do you have dyno numbers before the KB, because my car made 259 hp and 297 torque with pulleys, exhaust, tb, mass air, gears, and fuel pressure/timing adjusted with no dyno tune. I dont know where ya'll are getting such low stock hp(190-200) numbers from?

tmoss · Nov 29, 2006

Don 95Vert said:
But take a look at your torque curve, ...............What you'll see is a HUGE increase in power under the curve - i.e. average power at any given RPM. That's what makes the car go down the track...

Absolutely - look at this torque KB 1500 torque curve .....

smitty_64 · Nov 29, 2006

I think I am going to be sick now...I don't have a supercharger, but I do have 45 more cubes than you and an H/C/I combo and I am only getting 311/345, which I am definitely not happy with (Low for a Stroker). But you're doing pretty good on a 302. And I am familiar with the Dropping Off around 5200 and 5300 RPM. Mine should be well up to 6000. I was told that it was normal for a 302 to drop off at 5200 with a B303 cam though, so I am not surprised that you're dropping off there with a stock cam (if thats what you have).

SVT3183 · Nov 30, 2006

i say the numbers are low. my car made just a few hp and #'s (less than 10) less than that on a day that was over 90 degrees outside with a 7# pulley that was only putting out 6#'s that day and my blowers is a 1.7 kb. my car was just retuned this week and i'll have the new numbers on monday. *supposedly* it made 385 #'s of torque when the motor was hot as hell. i'll have post a graph when i get it, picking the car up monday. both times were on a dyno jet.
what is your a/f and what type of dyno was it?

Guero · Nov 30, 2006

What color is your car??? My cars is getting fixed there! Keith is a cool guy to work with, what year is ur car?

BlackVert · Nov 30, 2006

tmoss said:
Absolutely - look at this torque KB 1500 torque curve .....

lol look at the name of the blower on your dyno graph ... i didn't know kenny brown made twin screw blowers!

BlackVert · Nov 30, 2006

Gixser said:
I know I am ranting and jumping around but I just dropped 5k on 120 HP and it sucks

dang, mine is for sale for $1750, and it's polished!

1st Dyno run on my KB Cobra

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