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Higher stall, slower ET

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Old 10-06-2015 | 08:27 PM
  #21  
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Thanks for the reply prostock John.

I am not logging nor do I have my own tuning software. The car was tuned after the cam install, but was not retuned after I bumped the stall up.

If I remember correctly the shift points are set around 6200-6400.

I tried not to idle to much in the lanes if I could help it and I was running the fans while I waited. I will look into the high IAT and that ram air you mentioned.

Do you think it would be worth getting the tune double checked?
Old 10-08-2015 | 12:06 PM
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Yeah I would.

Ideally if your tuner could hit the track with you, you could log and see what it's doing. Those shift points might be low, plus if you log you will know for sure where it's shifting.

Converter lockup is useful to look at too.

I've seen folks with your mods go anywhere from 11.4 to 11.7 dialed in and with some weight reduction.

-----

We did a lot of track tuning with my 2010 last Thursday and it made a big difference. Went higher on the shift points than I would have expected, but also a surprise, we keep raising the TC lockup RPM because that's what it wants. I would have thought opposite from what I've read.
Old 10-09-2015 | 06:41 AM
  #23  
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Thanks again John. Those are the type of numbers I was hoping for once I got the suspension all dialed int.

I will talk to my tuner about looking at the tune and I would love to have him at the track with me , but don't think that will happen.

I may just have to finally buy HP tuners and start learning my self how to use it.

I am planing on hitting the track tomorrow and it seems I have my IAT issue worked out so hopefully it will do a little better. I will post my results.
Old 10-09-2015 | 11:10 PM
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Good luck.

HPT is pretty easy to use. I have changed my own shift points.
Old 10-10-2015 | 04:51 PM
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curious how you made out today and what was causing the iat issue ?
Old 10-13-2015 | 07:01 AM
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All I did to the IAT was removed it and cleaned it and the IAT's seem to be fine now.

I went to the track on Saturday and made 2 good passes. First was 12.02 and second was 11.98. The DA was between 1150 and 1200. I will upload the slips after work. I am close to where I was before the stall change, but my ET has not benefited from the stall change or the better 60 ft.

I talked with the tuner and he seems to think that my shift points should be fine and I am losing on the big end due to converter efficiency. He told me when he tuned the car that the stall was good and not to raise it.

I talked with Precision Industries and they said we that small increase in stall and at 3600 the efficiency should not be that different from when it was at 3200. And 3600 is not even that high of a stall compared to what some people run.

I doubt the stall is too high, I see people with higher stalls all the time that do not complain about efficiency. In fact when I was at the track there was a bolt on Camaro running a Yank 4000 stall, I forget which model and a bolt on GTO running a FTI 3600 stall.

Any thoughts would be great and I will load up those slips as soon as I get a chance.
Old 10-13-2015 | 04:10 PM
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This is Brian from the track. First, it was nice meet you! Second, I have a SS4000. Third, I'm not sure what is going on with your car.

You run a full tenth faster 60' than your previous best, but show no ET drop. Your MPH should stay the same as you didn't add power or take weight out and assuming the converter is just as efficient.

Our last passes have basically the same ET so I'm sure it can't hurt to compare slips to narrow down the issue:

60': I went 1.71 and you went 1.65(?)
1/8: 7.632 @ 90.37 (I'm not sure what you ran)
1/4: 11.979 @ 112.92 11.98 @ 114.5

It doesn't make sense that you left quicker by .06 but we ended the same with you trapping higher.

Imagine this: We have the same reaction time. You would pull ahead right away, but I would pull head probably shifting into second. By the end of the track, you have 1.5 mph on me and catch up to dead even.

Basically, something isn't as efficient as it should be between the start and finish. I really believe you should be shifting at at least 6500 with your cam and not your current 6200-6300 like you said. I'm shifting at 6200 with the stock cam. I believe you are shifting short of the ideal shift point for your cam and those couple hundred rpm aren't being carried from the 1-2 and 2-3 shifts through the run. I really think you have a few more mph in your setup.

How does your trans feel? Shift quick and hard? If it's slipping any, then I can see how you are getting mixed results. If it's good, then it's probably in your tune. Here's my last pass if you want to see how my rebuilt trans shifts with the Yank converter and Frost tune:

Last edited by Hardtop Brian; 10-13-2015 at 04:20 PM.
Old 10-13-2015 | 10:39 PM
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Ur iat's should never get up to 178 degrees especially checking right after a run. With my hood closed running a/c letting the car heat soak my iat's only got up to 120s, turned the engine off and they only went up to 140. I was specifically testing iat's when I did this. I let the car run for awhile so it got really hot.
Old 10-14-2015 | 06:53 PM
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178 IAT is a sign of a failing sensor. 6,200 rpm is way too low of a shift point.
Old 10-19-2015 | 08:50 PM
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Thanks Brian for the input and it was nice to meet u too man. I watched the video and my car does shift firm, maybe not as quick, but hasn't realy changed since I had the car.

I emailed Geoff at EPS to ask his opinion and missed his call but will call him back tomorrow.

Also here are the two good passes time slips that I mentioned earlier.
Old 10-21-2015 | 09:45 AM
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IAT's are way too high and your shifting the car way too low. Needs to be up around 65-6600rpm minimum.
Old 10-25-2015 | 02:13 PM
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Id shift 6800 ish. I have an f14 cam and i slowed a 10th by shifting 6600 instead of 7000 rpms efi live data logged.
1 mph as.well.
Old 10-25-2015 | 02:18 PM
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Originally Posted by AINT SKEERED
Id shift 6800 ish.
easy for you to say , you AINT SKEERED lol
Old 10-25-2015 | 03:12 PM
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Originally Posted by murphinator
easy for you to say , you AINT SKEERED lol
Drive it like i stole it but pamper it like a baby in appearance
Old 10-26-2015 | 11:23 AM
  #35  
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I will definitely have to buy HP tuners or have the tuner adjust my shift points. I think that's where I am losing it on the big end. Thanks everyone for the info and I will update any changes.
Old 10-30-2015 | 04:06 PM
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Really handy to have your own copy of HPT.

We have tune the bejeezus out of my car the last 2 times we have been at the track, almost in the 10's.



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