Low mph? 9.8 @ 138mph
11-07-2013, 09:28 PM
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Low mph? 9.8 @ 138mph So last month my 3800lbs TA went 9.8 @ 138mph with a 1.45 60ft.
Now there was a 27mph head wind but I don't think that had a huge effect.
The car put down around 850 875 whp but I was having issues with it starting to drop off at 5400rpm.
Same exact setup on a differant dyno 10 months ago was pulling to 6300rpm.
I swapped out springs, shimmed the new dual prc to 185 seat pressure, closed the gap on the tr8s to .022, went with a fatter pushrod. Went back to the dyno with the same results.
Now there was a 27mph head wind but I don't think that had a huge effect.
The car put down around 850 875 whp but I was having issues with it starting to drop off at 5400rpm.
Same exact setup on a differant dyno 10 months ago was pulling to 6300rpm.
I swapped out springs, shimmed the new dual prc to 185 seat pressure, closed the gap on the tr8s to .022, went with a fatter pushrod. Went back to the dyno with the same results.
11-07-2013, 09:31 PM
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I was running out of time for the season so I went to the track like that and went 9.8 @138. At 20psi
Last year on a weaker launch and 100whp less (smaller turbo) it went 10.1@138 on a little less boost (18psi)
What am I missing? Is that a normal mph? My turbo is a comp t4 88 billet comp wheel 94/88 turbine. Very similar to a pt88 which i see people knocking at 150mph all the time.
Last year on a weaker launch and 100whp less (smaller turbo) it went 10.1@138 on a little less boost (18psi)
What am I missing? Is that a normal mph? My turbo is a comp t4 88 billet comp wheel 94/88 turbine. Very similar to a pt88 which i see people knocking at 150mph all the time.
11-07-2013, 09:40 PM
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I also swapped back to stock rockers, no change. I think with more seat time and tuning it will go 9.5 so I'm happy with the et just wondering how much faster it can go with my issue fixed.
11-08-2013, 08:36 AM
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I did log but not verter slip. I have a vig triple disc so maybe i can experiment with locking it in 3rd. I just that with a peak of almost 900whp the car would go faster.
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11-08-2013, 09:29 AM
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Cam,232/236 .595/.601 115+4lsa xer lobes
I can send the tune but its 18 degrees pasy 5500, its 19 20 in spool up then 16 at peak torque.
Exhaust is 4 inch dp to a boost activated cutout then connected to a 3inch. The 4 inch boost cutout opens every time and dumps right to the ground.
I do run a smaller k&n style cone filter right on the turbo. Its about 6 inchs long.
What's odd is that I've had it on the dyno(a different dynojet) and its made power and not dropped off till about 6300. The only thing that changed was about 10 months and the dyno. I did add meth but i tried the meth at 11.3 afr and 20 degrees with same result.
I can send the tune but its 18 degrees pasy 5500, its 19 20 in spool up then 16 at peak torque.
Exhaust is 4 inch dp to a boost activated cutout then connected to a 3inch. The 4 inch boost cutout opens every time and dumps right to the ground.
I do run a smaller k&n style cone filter right on the turbo. Its about 6 inchs long.
What's odd is that I've had it on the dyno(a different dynojet) and its made power and not dropped off till about 6300. The only thing that changed was about 10 months and the dyno. I did add meth but i tried the meth at 11.3 afr and 20 degrees with same result.
11-08-2013, 09:37 AM
#13
20 psi should have gotten you more MPH without a doubt as you know. The filter is small but that shouldnt restrict you that much. Try taking it off and taking it for a ride see what the difference is. 18 deg timing 20 psi on an 88mm should be enough for 160 depending on the trans/gear/converter combo
11-08-2013, 09:47 AM
#15
Your ET will all depend on a bunch of other factors, how fast does it spool, rear gear, timing curve...etc. Log it, see what RPM you go through the traps, see your RPM drop between shifts, your converter might be efficient but just too tight? Then again you could loosen the converter up and lose efficiency but gain ET by losing the RPM drop between shifts..? So many factors.
11-08-2013, 11:03 AM
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Here are some dyno graphs, the first graph is the first time I went to this other dyno and did some meth tuning. Thats when I saw a huge drop off so I changed the springs, pushrods, put stock rockers on and gapped the plugs at .022. The graphs after that are with all the new valvetrain stuff.
