MORE POWER

[MPGmustang]

okay okay, I think I agree with you guys, the economy has gone down, the response has gone down, warmup time has gone beserk so obiously the controlled (although it's actually constant) vacuum leak helps... alot more than just blocking it off. but it was cool to see...

next air filter replaced, 61jets replace the 58 jets... needs more gas... also think I need to retard the initiall timing. and see what that helps... think 15 is too much, I'll try 12 for a tank or two with the 61 jets.

otherwise very intresting. should be able to hit the dyno agian in 2 weeks I'll try to grab a really cold day.

 

[MPGmustang]

man do I have this all wrong... I thought I needed more gas before and less initial timing but I was wrong... and the dyno showed me up...

anyways little update, and hp record!!!

143hp
156tq

Okay okay.. lets not get too excited. Time for some bad news. I lost avg 5hp and 10tq for the entire range from 1800rpm to 4000rpm. I'll post a graph monday. it's kinda a win loose day for me. main changes were carb rebuild, and 1.6 rockers installed. can the 1.6 rockers really loose low end tq?

well I'll be heading back to my dyno shop this time to try it again, swap the 1.6 rockers with the 1.5 rockers and see the difference. the carb is jetter better now, but still little rich. and I would like my DUI recurved. all will happen after I drop in the 4.11 rear axle I have waiting for it. so much I want to do and so little time.

besides the rockers what else could cause such drastic loss? 5hp and 1tq lost for 2000+rpm (1800-4000rpm) is kinda big. top end came alive little more but that's only 200rpm range and I can't use that. anyways much thanks guys.

 

[170-3tree]

I bet that if you have that DUI curved and then re-tune it all around that you will hit your 150 mark next time. It will just pull all of that great stuff into a unified system rather than a semiunified mess. You didn't toy with cam timing this time did you?

 

[MPGmustang]

I bet that if you have that DUI curved and then re-tune it all around that you will hit your 150 mark next time. It will just pull all of that great stuff into a unified system rather than a semiunified mess. You didn't toy with cam timing this time did you?

No I didn't change the cam timing, I'll be keeping it at 4* advanced I think it's good there. the timing can absolutely improve, I had 3 runs 132, 139, 143 (my computer shows 145hp due to settings but it is the same file) the first change was 61 jets to 59 jets in teh carb, it was awefully rich (11.5 first run) the jets helped it to 12.4, then on the 3rd run I advanced timing to from 8* to 14*, in the end I ended up with 11hp gain from the tunning.

http://i897.photobucket.com/albums/ac17 ... vsnew2.jpg

This shows my runs, Red is old best, and blue is new best, as you can see I lost alot of bottom end to gain that tad bit of top end.
the carb rebuild helped, as before I was riching up at the end now it's consistent for the whole range. (it looks wavy but it's zoomed in between 12 and 14)

I think I have an issue with this dyno place. they can improve engine performance by running them at temp. my original dyno place would do 2-3 runs before changing something to get an "at temp" baseline. by getting a great at temp dyno in, they are able to show what the HP is at proper running temps, not sitting cool temps. I'm going to go back to my dyno place and run it again as is with the current setup just to get a better "at temp" run. I have see in the past runs, sometimes the power goes up and other times the power goes down, and everyone once in a while there is a "OMG a 15hp jump" moment that I can't repeat how ever hard I try but I remember it was cold on that try.

 

[bubba22349]

I'm going to go back to my dyno place and run it again as is with the current setup just to get a better "at temp" run. I have see in the past runs, sometimes the power goes up and other times the power goes down, and everyone once in a while there is a "OMG a 15hp jump" moment that I can't repeat how ever hard I try but I remember it was cold on that try.

Good idea going back to first Dyno place sounds like they would be more careful and more accurate. Even if you had two identical Dyno's in locations close to each other they won't read exactly the same than add in the different operators and can make it hard to see if you are making progress sometimes. Would be good to keep a master log of conditions for each run time date etc. temp. Humd. etc. and mods that were done this can sometimes help with tuning decisions at the races too.