Dyno #'s

[jay97lt1]

I got my car dynoed and is dissappointed in my #'s I started with a base main oder tune at 267 hp and 339tq ended up with 322hp @5350 rpm and 347tq @ 4350 My tuner says I have a good setup its just running out of air what can I do to get my #'s up
383 11:1 comp. comp cam XFI 292 cam ported stock heads intake and TB 1.6 roller rockers Moroso CAI

[jaysz2893]

Auto or 6 speed? Gears? My bolt on 6 speed (3.23 rear) was 305/351 without the new intake and exhaust. Dyno's are good for dissapointing you. was the base line and tune all done on the same dyno at the same time? If so 55 more hp in a tweaked tune is good. How did he know it was running out of air? WideBand 02 readings? lean or rich can make a big diff.

[jay97lt1]

My tuner told me it was falling on its face after 5400 rpm M6 car
same dyno same time

[popo8]

is your set up NA????

I had the same issue on the dyno when we first got mine together, turned out the procharger was sucking the inlet hose shut...

If you are NA, ignore what I wrote above....

[jaysz2893]

"falling on its face" could be drop in Fuel Pressure. Mine did it once @ a Dyno Day. My FPR was on the way out. That being said it could be a lot of things on a cammed car. Maybe someone else has some more insight.

[thumpinglt1]

is it a mustang dyno?

[jay97lt1]

fuel perssure is good he checked it dynocom dyno

[Joker Z28]

God, I would think you should be closer to 400hp with that set up.
I am not sure whats wrong with the car or how to get more air.

[jay97lt1]

I know I need a 58mm TB

[Fastbird]

How big is that XFI 292 cam??

Here's my initial thought: Find another dyno. My first thought after reading your posts is that either the dyno is calibrated wrong, or you've got serious issues with the motor. The first is more likely IMO.

[jay97lt1]

RPM range 2200-6200 Duration @50 242/248 lift 584/579 113 lsa

[95.383.z28]

how do you like that cam? i was thinking about getting that same one for my car.

[jay97lt1]

I love the cam it sounds great

[AChotrod]

What kinda exhaust and who ported the heads??

[jay97lt1]

Carolina Speed shop did the heads . Pacesitter long tubes ORY Corsa 3 inch

[Flyinz]

Do you have a dyno graph? I wonder, how the tuner can tell, the engine is running out of air..or is it an ignition, or valvetrain problem?

[jay97lt1]

2425dyno sheet

[blackbird1084]

It looks like it very well might be running out of air. What do the heads flow? What's the tb size? And is you intake ported?

[jay97lt1]

some ppl r saying Iam way to lean but I have no clue

[jaysz2893]

some ppl r saying Iam way to lean but I have no clue


AFR
The Air fuel ratio is the most common reference term used for mixtures in internal combustion engines.
http://upload.wikimedia.org/math/f/8/b/f8bd4be2520724da4a3de13a03796be8.pngIt is the ratio between the mass of air and the mass of fuel in the fuel-air mix at any given moment.
For pure octane (http://\"http://\\"http://ltxtech.com/forums/wiki/Octane\\"\") the stoichiometric mixture is approximately 14.7:1 or λ of 1.00 exactly.
In naturally aspirated engines powered by octane, maximum power is frequently reached at AFRs ranging from 12.5 - 13.3:1 or λ of 0.850 - 0.901.

Your AFR is showing levels of 20:1 @ 2500 and then again at 5000. It bearly hits 15:1 under load.


Any mixture less than 14.7 to 1 is considered to be a rich mixture (http://\"http://\\"http://ltxtech.com/forums/w/index.php?title=Rich_burn&action=edit&redlink=1\\"\"), any more than 14.7 to 1 is a lean mixture (http://\"http://\\"http://ltxtech.com/forums/wiki/Lean_burn\\"\") . Lean mixtures produce hotter combustion gases than does a stoichiometric mixture, so much so that pistons can melt as a result. Rich mixtures produces cooler combustion gases than does a stoichiometric mixture, primarily due to the excessive amount of carbon which oxidises to form carbon monoxide, rather than carbon dioxide. The chemical reaction oxidizing carbon to form carbon monoxide releases significantly less heat than the similar reaction to form carbon dioxide. (Carbon monoxide retains significant potential chemical energy. It is itself a fuel whereas carbon dioxide is not.) Lean mixtures, when consumed in an internal combustion engine, produce less power than does the stoichiometric mixture. Similarly, rich mixtures return poorer fuel efficiency than the stoichiometric mixture. (The mixture for the best fuel efficiency is slightly different from the stoichiometric mixture.)

Your's sure looks like it is not getting enough air or fuel. It could be a simple a s a clogged Fuel Filter or undersized injectors. You shoudl not need a 58mm TB. A 52 shoud be enough.

[jay97lt1]

Thinks for clearing that up I had it backwards Iam running 30lb svo injectors and filter is brand new. Could I have a air leak in my CAI system causeing it to be lean

[jaysz2893]

maybe an Intake or CAI leak after the MAF, but more importantly does the tuner have the Lean vs Rich thing right and adjusting the Fuel tables accordingly? I was talking to a friend last night who DIY tunes his car and he said 20:1 is BAD. 15:1 under load is not too bad, but would rather see 13.8:1 at the least to be "safe". Too rich can cause "wash down" where the fuel washes the cylinders and that can make big problems. any more lean and you will melt or pop something.

[jay97lt1]

I borrowed a snap-on scanner from work and scanned my car my AFR is 12.7 at 850 rpm's and 14.7 @ 2600 rpm's and my timimg advance is 37 @ 850 and 45@ 2600 rpm's

[jaysz2893]

well then the dyno you were on was off on it's A/F readings for sure.

[jay97lt1]

I did notice he used a scanner to check my AFR on the first dyno run but I had to leave after that

[badfnta]

those are low #'s for a cammed car.