pull #1 was very similar to my 180 hp pull from last week. it peaked at 178.4 HP and 173 tq. the graph has a 'jump' about 4600ish RPM to 5000 RPM in which horsepower increases roughly 35ish. its like a 'step' in the power curve. nice arc, jump, arcs again. oh yes, the AF curve bottoms out then comes up to 12:1 then settles to 11.4-11.5. this would create the step.

now run #2 was completely different. peak HP was 174.8 and TQ was 188! the curve for HP was damn smooth up to about 5600 where it starts to jig-jag about 10ish HP to redline (spark breakup and an insanely low 11.4:1 AF ratio). AF ratio was a steady 11.5:1 without the sub-10 plunge. torque was also smooth and consistently was 15-20 lb/ft over my other run. BUT! the curve is linear and makes a nice arc, whereas all of my 178-180 hp pulls all exhibit lower torque/more peak HP/the 'jump' in the mid range.

i would like comments from others who have dynoed their MSPs: did you experience similar differences in your pulls? i want to know why my car sometimes yanks fuel and sometimes doesn't. also, read my other thread regarding developing a voltage limiter for creating boost over 10 PSI...

 

the jump in your curve at 4600rpms is the VICS opening up. If you could wire it open you would probably see anincrease across the board...

I have no clue about the second graph. Sounds like a supercharged graph with detonation. I can tell you've got the boost turned up or else your AF's would be in the 8's. These cars are friggin gas-pigs. I'm telling you right now you should SERIOUSLY purchase a Haltech F10X from me and run it's maps. You'll save yourself a lot of headaches and spare us from having to read "Well Matty was right....I blew my motor today"

 

more than likely, you are right about the Haltech! i would like an Autronics tho... MMMmmmMMMMMMmmmmmmmMmMMmmm... but my pride would prevent me from ever posting up about busting a motor.

 

****, thats the first thing I did...


I BLEW IT!!! WOOOHOO!!!

hahaha, but seriously the value of the $999 Haltech will shine the first time you start detonating....trust me.

 

didnt think MSP's had VICS...MP3's didnt....

 

yup mp3's are the only ones who DONT have it.....and what you mean is VTCS....


VICS is the secondary runner system....VTCS is the tumble control that makes the car sound like a diesel when cold.

 

VICS....VTCS....11.14:1 AF....




you lost me.

 

VICS--variable intake control system---dual runners switchable based on rpms...

VTCS--valve tumble control system--helps it warm up faster

11.14 AF--air fuel ratio....the proportion of air to fuel....11.14parts of air to 1 part fuel....stoich is 14.17:1 (I believe). The leaner the mixture the more power but more prone to detonation. 11.17af is pretty good for a street car.

 

14.7:1 is stoichiometric, but more power is made richer. somewhat leaner fuel curves make for nicer emissions.

12.5:1 on pump gas is pretty good.

 

By stoichiometric, do you mean the optimal ratio for combustion? Stoichiometric simply means a scientific calculation of a reactants in a reaction.

Also, I thought that richer mixtures made for better emmissions because the temperatures and dynamics of the combustion, the only leftovers are water vapor and carbon monoxide which can both be handled by the cats.

Leaner mixtures create nitrous oxides with their combustion which are "bad" polutants and aren't very well handled by the catalysts in the converters.

This is likely why when you get a CEL for the Cats, the engine starts running horribly rich losing power and mileage.

How can you get AF readings from the engine btw?

 

ok, that makes a lot more sense. thanks matty. cant you tell im new?

 

Viletster. AFR's can be checked by wideband or narrowband o2 sensors. Forced induction cars (usually turbos) run a 3rd o2 sensor and that sensor is run directly to its own guage. This sniffs the exhaust gas before any cat and determines the pre-combustion mixture based on whats left over.

Ken from p-garage bought one for his turbop5 and it was $440. That is almost half what they retail for. They are very pricey and there is no tuneability with them...just monitoring. If you don't have a chasis dyno with wideband tuning near you though this is an invaluable tool as it will help you save your motor should it run lean.