'94 mtx results

[jayro]

Just got back from a Dyno Day here locally. Let me know what you think

203 hp
193 tq

My a/f ratio seemed a little lean. It was between 13-13.5 for the whole run. I have a Ted B LPM that I was going to get redone at SHOsource...hoping there maybe some some tuning HP there. Its a 3.0L with 170k miles on it. My mods are:
Catted y-pipe
bbb, P+P intake
pmass 75mm maf
udp

HP was over 200 from about 5500 to 6500 rpm and was still making about 180 at 7K. TQ started dropping about 5600 rpms.

Jeremy

 

[SuperHO]

seems pretty damn healthy to me.

 

[Sho Amo]

yeah. it also sounds very accurate. Id bet taking that chip out would lose some power.

 

[jayro]

yeah. it also sounds very accurate. Id bet taking that chip out would lose some power.

With the drop in MAF I was a little worried about the A/F ratio. I thought I remembered reading that in the 12 range was where SHO's made there best power. I was going to keep the chip, but send it in with the dyno data to try and get a little bit closer. Am I mistaken about the A/F ratio?

Jeremy

 

[1993MTXSHO]

Sounds just about right, my 93 mtx ran 205hp and 195 ft tq with the same mod (I had a bone stock intake though no BBB or ported runners) and a lot less miles, give or take dyno erros and id say you have a decently healthy engine for the mileage.

 

[Sho Amo]

12 range was where SHO's made there best power

Imo 12 is pretty rich. i would think 13 is not too bad. The stock commanded a/f is 14.6 so your definitely safe where your at.

 

[jayro]

Imo 12 is pretty rich. i would think 13 is not too bad. The stock commanded a/f is 14.6 so your definitely safe where your at.

Thanks for the info. I'll just keep it as is for now.

 

[38SHO]

14.64 is the chemically correct number, this is when all air and all fuel is used in the combustion process equally... as in everything is used and there are no leftovers of the other substance

I've been reading on higher rpm N/A engine that 12 to 12.5 is a good number

but all things can be different, not one number works for all engines, or any car with a particular engine even.... the more I learn about this, the more I realize I had no clue what was going on....... like I bet you thought air is always sucked through the intake manifold into the combustion chamber... boy did I find it wierd that air also comes out of the combustion chamber, back into the intake, and returns back to the combustion chamber, and good engineers figure this out, the length of a runner, and bring that air back into the CC just before the valve closes... thats some trick shit there and do you know where the source of that air pressure comes from that brings air out of the CC and back into the intake manifold, then back into the CC? exhaust exiting your tail pipe...... people talk about tuned exhaust systems that help scavenge out exhaust fumes from the CC... but it is 10x more involved then that...... there are other factors that help this "tuned" effect....

 

[1993MTXSHO]

12-12.5 is where you want to be on a n/a sho I would THINK but who knows maybe stock isn't as bad as peopel think it is. Commanded is 14.64 yes, but the sho runs 10's in the upper rpm's. FWIW area 91 dynoed his car with a 13:1 ratio vs stock and the 13:1 lost power across the board.

 

[jayro]

12-12.5 is where you want to be on a n/a sho I would THINK but who knows maybe stock isn't as bad as peopel think it is. Commanded is 14.64 yes, but the sho runs 10's in the upper rpm's. FWIW area 91 dynoed his car with a 13:1 ratio vs stock and the 13:1 lost power across the board.

I may have a little tuning done and then rerun it. My A/F ranged from about 13.1 to 13.8 depending on the RPMs. Then it dropped from 13 to 12.5 between 6500 and 7000. The problem is that if it is adjusted and I rerun it I won't know 100% if it was the tuning that changed the output or if it was the daily conditions. If only I had a tweecer I could tune on the dyno and know for sure.

 

[bubba]

Nice numbers... I wish I could have made it up there! Was tried from the trip to Indy the day before!

 

[jayro]

Nice numbers... I wish I could have made it up there! Was tried from the trip to Indy the day before!

THe guy said he was thinking of having another one in a couple month. I'll let you know when.

Jeremy