1994 Mustang GT 5.0 5-speed,stock engine,K&N air filter,BBK shorty headers,Summit o/r h-pipe,Flowmaster American Thunder Exhaust. good first run,driveshaft vibration.(will look into it over the thanksgiving weekend) second run aborted,started to ping. 12*BTDC,87 octane.should have put 91 in. guess thats what i get for being cheap on the gas the idea was to run the way i drive it,i dont see those rpms too often. next time it will have 91. heres the graph. and the video. Dyno Shootout :: DSCN1813.flv video by hdavis3_bucket - Photobucket Thoughts? i'll post up some pics and videos the other cars later.
Hmm...I'm sure more intelligent people will chime in here soon but, to run 91 octane wouldn't timing be at 10*? Also, would your car benefit from a cold-air intake? Also, your driveshaft vibration could be from a bad dampner or loose bolts? I had a problem with mine backin out. Overall impressive run for a stock, exhaust only car!
thank's. when i installed the alum driveshaft,i replaced one u joint.the other looked good but i'm gonna replace that one next week. balancer is good and bolt is torqued to spec. also,my car is very low,i played with the pinion angle alittle,i got an angle gauge,need to check that too.
If you are going to run an advance in timing at all, you should not be running bottom grade. That's really just kinda asking for trouble. I have also found that 94-95s do not allow the same 'window' for timing advance as a fox when using the lower grade fuel. Might be from a faster ramp rate in the maps idk, but rule of thumb is it seems to be a 2 degree offset from ping to no ping. It should like 14 degrees on good gas. However and what makes a good point, is that IF the balancer IS going bad (which the do as mine **** the bed) they will not only cause the vibration you are experiencing but it will be slightly spun from center and the actual base timing might not be correct from what you can see. In otherwords on a stock balancer 10BTDC is at 10BTDC. On one that is bad it might read you are at 10BTDC but is really closer to 16BTDC. Just something to think about. FWIW CIA's don't show much on a dyno, but they do help in real life. Nice baseline at least. Now you gotta get some real mods at it! They get alot more fun with @300whp and another 50+ lb ft tq. Then add some boost
Looks Good Harvey I agree about making sure the hb is not hosed :Word: That way you can go max spark with good gas and You will know for sure what you got Pulleys & Intake (not pipe) would be good next mods Grady
Harvey...does your car still have the damper on the rear end?? Sometimes that can also cause driveshaft vibrations IIRC.
hi Grady. thanks. i've got the explorer intake and some gt40p's. i'm looking at the trick flow valve spring upgrade,tfs stage 1 cam,and a fresh valve job. prolly not til next year,though. over my 4 day weekend coming up.i'll sort out the vibration. after i get rid of the vibration,and have some good fuel,i was thinking about going for a couple more pulls. not sure if thats worth the $110 for 3 pulls and air/fuel readings
The aluminum driveshafts should have new and very high strength universals on the yoke and carrier end? Was yours not a ford racing one? Are you sure the balancer is good?
its ford racing,but i got it used. car had light front end damage,one headlight busted and a dented up fender. the u joint at the yolk did not move freely. i thought i read somewhere that an improper pinoin angle can cause a vibration. what could cause a high speed vibration? happens at 115+ mph.
Roush 427R. 385hp,340tq Dyno Shootout :: DSCN1817.flv video by hdavis3_bucket - Photobucket A nova,i think. 74hp,121tq(at least some made less than me) Dyno Shootout :: DSCN1822.flv video by hdavis3_bucket - Photobucket
Damn Harvey, sorry I couldn't be there. I was stuck at work until 3:30pm. I will however get out to your pad for those seats tomorrow Also finally give you those valve covers I cleaned up LONG AGO! LOL... Anyhow, I'll see ya soon man!
That's a little on the week end even for 87' Octane. The car should do 190rwhp+ bone stock. I would go ahead and change the U-joints on it. You can get the really strong ones from the Autoparts store, the Brute Force ones, or whatever that particular store calls them. The driveshaft might have thrown a weight. It should be around $35 to get it rebalanced at a driveline shop. Kurt
Of course the second run would suck, no time to let the motor cool down, the second run was worthless. It's fun seeing your car on the dyno, but I always get nervous that something catastrophic is going to happen!
ok guys. i got rid of ALOT of the vibrations. pinion angle was way off. measuring at the pinion flange,with car even and supported at the suspension(front wheel ramps,rear jack stands under axle)the angle was +1. with another set of stands,i raised the rear and supported it by the body,allowing the axle to drop down. next i disconnected the upper control arms and shortened them 2 turns. then i reassembled everything,and placed the axle back on the stands. checked the angle again and it was -1 1/2. double checked all my bolts were tight,lowered the rear. i took a run down the highway(clear,no traffic,of coarse) i hit 132mph in 5th gear and it felt really good(remembered i had 87 in so i let off) before at 115mph,the vibration was so bad it was scary. notice in the video he only went to 121mph. i still plan on replacing that u joint and having the driveshaft balanced.
i know. but the only time the vibrations occur is at those speeds. how else could i verify if it was corrected?
Hey Harv, when you're ready... I might want to do the 3.73s with ya! Let me know! We can do them both at the same time. Thanks for the seats again man! Now to hit the yards looking for a black rear and black carpet.
got all the video's i took uploaded to youtube. some are with my little nikon,other are with my cell you can tell which by the poor quality. heres the link. YouTube - davis3xiong's Channel
