Goal= Tens

[pneumo]

Hi all! It's me again, the guy who went 11.98 @114.9 on a 14b with stock sidemount IC, stock injectors, and stock IC pipes. Now I have some real mods on the car and I'm shooting for a ten second timeslip, most likely deep tens.

Normally I wouldn't be so bold and make predictions like this except that something GOOD happened just the other day and I wanted to pass it along to see if it holds water.

First a little background: I had a total of 2 runs this season on the new setup, not much driving time under my belt. Here's the vid of the second, successful run. 11.3 @ 130 mph http://video.google.com/videoplay?docid=3123757668280571397 If you listen to the sound of my motor you can hear me back off the throttle in the middle of first gear. I did this to make sure the tires were hooked up. It's a good thing I did since the logger showed rpm drop back down at that point, indicating the wheels were spinning. It also took too long to get through first gear. The second thing you can hear is how slow I was shifting, the revs spike up at each shift. Obviously I wasn't pushing for my best time. Everything came to a halt at the end of the return lane when the tech inspector kicked me off the track for not having the proper safety gear. I didn't get a chance to really flog the car yet.

A few days ago I took the opporitunity to do a few baseline dyno pulls at the local and growing AWD dyno shop at Full Function Technology ( www.FFtec.com )
This was a VERY good thing!
The first pull was with the same tune I used to run 11.3@130, which netted 439Whp on a Mustang dyno. See first pic below. I read the log and poked the SAFC a few times between runs. The second pull netted 435Whp, but with a broader, flatter powerband. I was very pleased with the power gains at 6k and 8500rpms. I didn't mind seeing a few peak HP dissapear since the dyno room was getting hotter with my car idling in it. I didn't make any adjustments at 7k rpm, so I figure the slight loss was due to the heat. It was soo nice to see an immediate difference from slight changes in the tune. I'm definately going back again for more dyno pulls, and next time I'm bringing my laptop and Ostrich!

The other reason I'm really excited about this is because my datalogs show I was shifting around 7800rpm during the 11.3 run! My car is holding near peak power all the way up to 8500! Holycrapolie I had no idea my mods were flowing so good.

So where should I shift?

A quick trip to www.f-body.org/gears/ allowed me to see how low the rpms fall at each shift. Here's a quick copy-paste of a speed-in-gear chart for a 1G AWD. For the gear ratios and final drive ratios of other model DSM's, goto www.VFAQ.com/mods/Trannies.html

rpm 1st 2nd 3rd 4th

4500 22 40 61 81
4600 22 41 62 83
4700 23 42 63 85
4800 23 43 65 87
4900 24 44 66 88
5000 24 45 67 90
5100 25 46 69 92
5200 25 46 70 94
5300 26 47 71 96
5400 26 48 73 97
5500 27 49 74 99
5600 27 50 75 101
5700 28 51 77 103
5800 28 52 78 105
5900 29 53 80 106
6000 29 54 81 108
6100 30 54 82 110
6200 30 55 84 112
6300 31 56 85 114
6400 31 57 86 115
6500 32 58 88 117
6600 32 59 89 119
6700 33 60 90 121
6800 33 61 92 123
6900 34 62 93 124
7000 34 62 94 126
7100 35 63 96 128
7200 35 64 97 130
7300 36 65 98 132
7400 36 66 100 134
7500 37 67 101 135
7600 37 68 102 137
7700 38 69 104 139
7800 38 70 105 141
7900 39 71 106 143
8000 39 71 108 144
8100 39 72 109 146
8200 40 73 111 148
8300 40 74 112 150
8400 41 75 113 152
8500 41 76 115 153

To figure it out just look at how fast the car is going in first gear at 8k rpm (39mph) then look at the same mph in the second gear column. answer- 4500rpm. I shifted from 2nd to 3rd at 7800rpm and the rpms droped to 5200. Looking at the dyno chart at 5200rpm the turbo is just barely spooled up! I was loosing power, speed, and time by shifting so early. Next time out I'm going to shift much higher.

Here's where I could use some input. Based on my dyno charts, where should I shift? I plan to try shifting 1>2 at 9k (rpms drop to 5200), 2>3 at 8700 (rpm drops to 5800), and 3>4 at 8k (rpm drop to 6k). The reason I'm asking is because the speed-in-gear chart doesn't take into account the torque multiplication of different gear ratios, so the power getting to the ground will decrease with higher gears. Anyone know how to factor that in?
Any other input is welcome!

 

[unlmtdndeavor]

wow dave, those are some nice numbers? what kinda gas was this on? also, what kind of head work, cams, and intake manifold do you have? i'm having trouble making peak power over 6800rpm, although i am still on a stock intake manifold and throttle body. i'd definately like my 30r making power up at 8k+rpm.

 

[SBstar]

So what is this new setup? Your mod list still sits as the same old stuff haha.

 

[super95awd]

Your A/F graph looks like butt, I'm sure that could be ironed out a lot. Other than that it seems like the car makes good power. I'm assuming c16?

 

[tstkl]

435, nice, how much boost were you pushing, and what gas?

super95awd, if he was using c16, I doubt it was pure c16, since he never really gets a chance to drain his tank. I believe he said he ran 50/50 for that 11.3 run, and I'm guessing it was something similar for the dyno too. Most cars come out of this mustang dyno with really low numbers, so that 435 is a big deal. IIRC, the highest hp car to come off that dyno was a 2.3 liter gt35r with a twin scroll t3 turbine housing .78 a/r. http://www.fftec.com/articles.php?article_id=159

thats the car I'm talking about.

its kinda weird to think that your car has run almost as fast, and can run faster, than a 2008 ferrari 599 gtb. Even though its rwd, it only has 1 mph on you, and thats assuming your tuning/new shift points don't change anything, .

 

[super95awd]

Oh those are definitely good numbers. I'm just saying with the a/f graph looking like that there's even more power left on the table. I'm sure he'll iron it all out.

 

[MyBlack94GST]

Hey Dave, check this site out if you haven't already:

http://www.welltall.com/ymc/discovery/car/shiftpt.html

 

[wortdog]

Here's where I could use some input. Based on my dyno charts, where should I shift? I plan to try shifting 1>2 at 9k (rpms drop to 5200), 2>3 at 8700 (rpm drops to 5800), and 3>4 at 8k (rpm drop to 6k). The reason I'm asking is because the speed-in-gear chart doesn't take into account the torque multiplication of different gear ratios, so the power getting to the ground will decrease with higher gears. Anyone know how to factor that in?
Any other input is welcome!

First off, your new shift points look just about perfect.

Second, when you base your shift points off of a horsepower graph, you don't care about the torque multiplication of the trans. If you pick the shift points to get the maximum horsepower under the curve between the start and end of each gear, starting with 1st gear and working your way up, then you guarantee that you're getting as much torque multiplication out of the transmission as possible.

For example, one way to find a good shiftpoint for 1-2 is to follow the horsepower curve through the RPM range until the horsepower you get in 1st gear at a certain RPM matches the horsepower you get when you shift to the next gear. Unfortunately, your dyno chart doesn't go out far enough to find it.

The largest compromise with the AWD cars is setting the 1-2 shift(due to the huge ratio difference), so sometimes you end up revving 1st gear out a little farther than ideal to make sure the turbo stays spooled in 2nd, as you've already done in your theoretical shiftpoints.

 

[pneumo]

Oh yeah, I forgot that I haven't updated my profile in a while. The motor and drivetrain are up to date in my profile, but I've added FP2 cams, JM smim, Q45 TB, 3" uicp, GT35 journal bearings with T3 .63AR hotside, tubular ex manifold, custom Newlogics O2 housing, 44mm external wastegate, custom 12x3.5x28 ETS fmic, 1k injectors and a very hacked 2G maf. I ported the head with some mild street porting, a little smoothing in the combustion chamber, and a little valve unshrouding. I used 100 unleaded gas for the dyno runs. 29psi of boost.

About the AF graph, I'm not exactly sure what's up with it, but I think we're looking at accel enrichment. I'm using the stock TPS sensor from the Q45 TB which isn't exactly compatible with the ecu. I had to change the code in the EPROM so the car would still drive normally. Which means I bumped up the accel enrich timer, thresholds, and multiplier by about 30%. Then I added a rubber throttle stop under the pedal to keep from overextending the throttle plate. Together it's easy to twitch the TPS just enough to trigger enrichment. At least that's my theory. I haven't had a chance to look into maf overrun yet. Either way I'm going to take out the rubber throttle stop and make one out of metal.

Mahesh, thanks for the link to the shiftpoint finder. I haven't crunched the numbers yet, but it looks like I'll need to shift even higher?! I'm not sure if my motor can take much more than 9k rpm. Nice find!

 

[diambo4life]

For the 1-2, if you can, don't lift. It makes a big difference in how the turbo responds after that shift especially. Everything looks good otherwise and that speed chart is dead on. I see 114-115mph in the logs at 8,500rpm when I lift after making 3rd gear pulls. This is on 215/45/17 tires which are slightly smaller than stock - diameter wise.

 

[pneumo]

For the 1-2, if you can, don't lift. It makes a big difference in how the turbo responds after that shift especially. Everything looks good otherwise and that speed chart is dead on. I see 114-115mph in the logs at 8,500rpm when I lift after making 3rd gear pulls. This is on 215/45/17 tires which are slightly smaller than stock - diameter wise.

I have no trouble with NLTS, I've used it for years and really like it!

It looks like I'll have to raise the revlimit and do a few more dyno pulls to see how the power holds (or not) up at 9k. Dam, I can't wait to take my car to the track and see how this works!

 

[T9S1i]

Nice numbers Dave! I finally got the 4-bolt in my car yesterday and I'm ready to hit the track whenever you are! Good luck with 10's. Are you going to change your tires/rims to DR's/15's or just try out the new shift points and put the throttle control that you've practiced with your laser into play?

 

[pneumo]

Nice numbers Dave! I finally got the 4-bolt in my car yesterday and I'm ready to hit the track whenever you are! Good luck with 10's. Are you going to change your tires/rims to DR's/15's or just try out the new shift points and put the throttle control that you've practiced with your laser into play?

I'll keep my Kumho MX's and see how they stick now that the weather is warming up. I'll still have to nurse it off the line, it's way too easy to blow the launch with wheelspin. A new set of DR with light rims would be awesome, but it's still a lot of money. I'm hoping to get into the tens consistantly with raised shiftpoints and better driving. I've only done a few runs so I don't have much experience launching the car with this setup. A little more practice should do the trick.

 

[T9S1i]

A little more practice should do the trick.

yes it should!

have you put the roll cage in yet? Let me know when you are going to roll to the track. Im going to be doing some tuning and whatnot soon so hopefully i can get the car up to at least 18psi on 91 octane and be able to roll with ya. Hell i'll even go if im on 12psi! It'll be fun to watch a local dsm'r run 10s!

 

[pneumo]

It's been a few weeks since I started this thread.
I just got back from the track. Here's how it went.

My first run was a total failure. I had a decent 60' time of 1.71, when I shifted into 2nd gear the clutch wouldn't grab and the revs spiked up to redline. I backed off the throttle a few times to see if it would grab, but no luck. Shifting to 3rd didn't help, it still slipped. Ran a 13.0@94mph.

I wanted more power so I did a little more tuning last week. I juggled the A/F ratios around 3k to 5krpm range, increased the scalar value in the eprom to reduce timing at high airflow, added a second spring to the wastegate to keep it from blowing open (it's a 46mm gate, wondered why the turbo spooled at 6k) Then when I got to the track I added a couple gallons of 116 octane, upped the boost to somewhere around 32? My gage only goes up to 30. I was worried that I still wouldn't have enough power to get into the tens. Going from 11.3 to 10.9 is a big jump! Could raised shiftpoints alone get the job done?

For the second run I made sure I didn't slip the clutch at all. I just hit the stutterbox and dumped the clutch. That worked- I got my best 60' time at 1.61! I nailed the 1>2 shift quick and let the clutch out quick. That worked too- second gear pulled so hard the tires broke loose and the car got a little sideways! yehaa! Having a Quaife front diff is awesome! But then the clutch slipped in 3rd and ruined the run. Luckily I rode out 2nd until 8900 rpm, so my time was good enough for a new personal best. 11.289@114.

I made sure to keep the hood open in the staging lanes to help cool off the clutch as much as possible. Being aggressive with the clutch was working for me, for the next run I just gotta do more of the same.

Run #3
another 1.61 60' time
clutch held in second
more rally drifting action in second gear
nailed the 2>3 shift at 8800rpm
clutch held in third!
nailed the 3>4 shift at 8300
clutch didn't grab at all in 4th!
It's OK I still went REALLY fast without 4th.

 

[pneumo]

who hit the submit button, I wasn't done!

Here's the slip. I'm so proud BTW I'm car #64, right lane. I wonder what mph it could've hit if the clutch held all the way through 4th? Stay tuned!

 

[silver bullit]

I think i smell a new clutch being on your order list. But nice times

 

[rhamlinii]

Nice setup. What clutch do you have and what weight have you taken out of the car?

 

[T9S1i]

haha, nice run dave!!! Congrats on the 10 second slip! I wish you would have given more advanced notice so that i could have went up there with ya! Even if my car isnt ready im down to go with ya so you can have some video taped runs for your collection!!

New clutch eh...And you just had the trans off to put on the scattershield too. time for the PTT twin disk or what? more seat time maybe?

What kind of car did you race against in your timeslip... they were right there with ya at the 60ft mark... almost. and then dave gave him the 1 finger salute and said goodbye!

Damn thats a nice mph for your 10 second run! haha, i wonder what it would have been if 4th only held...13x???

 

[MyBlack94GST]

Congratulations, you've earned it. Nice freakin runs!

Edit: Who called it?! 10.8! haha

 

[T9S1i]

yah ya did damn it mahesh!!!

 

[pneumo]

"I think i smell a new clutch being on your order list"
Yeah, 'smell' is the right word. Dam clutch, I think I found the limits of a Spec stage 3. I'm thinking of keeping the disc and just throwing on an ACT2600 pressure plate.

I've taken about 400 pounds out of the car. The rollbar didn't add much weight. Everyone says they're around 80 pounds, but I got a cromoly bar, which is lighter for the same strength. I felt the weight of one bar while it was being fabbed at FFtec.com and it wasn't heavy at all. I'm thinking with all the bars, plates and bolts the complete rollbar is maybe 40 pounds. Taking out the passengers seat made up for it easily.

Wow, I just noticed I broke into the 6's in the 1/8th! Sweet, 106mph aint bad either.

 

[silver bullit]

"I think i smell a new clutch being on your order list"
Yeah, 'smell' is the right word. Dam clutch, I think I found the limits of a Spec stage 3. I'm thinking of keeping the disc and just throwing on an ACT2600 pressure plate.

I've taken about 400 pounds out of the car. The rollbar didn't add much weight. Everyone says they're around 80 pounds, but I got a cromoly bar, which is lighter for the same strength. I felt the weight of one bar while it was being fabbed at FFtec.com and it wasn't heavy at all. I'm thinking with all the bars, plates and bolts the complete rollbar is maybe 40 pounds. Taking out the passengers seat made up for it easily.

Wow, I just noticed I broke into the 6's in the 1/8th! Sweet, 106mph aint bad either.

Got any pics of the car? Are you gonna try to get 9's?

 

[pneumo]

Got any pics of the car? Are you gonna try to get 9's?

9's? that seems so freakin fast at this point. I'm still giddy from the rush of going tens. For now I'm going to enjoy the car and try not to work on it too much. Well, except for a new clutch, but that's all I need! yeah, right. There's always more!

Here's a couple pics of the car and rollbar. From the outside the car looks very ordinary, nothing going on here, officer.

On the inside it's all business. The upper seat bracket makes the seat feel very solid. The 5 point harness gives me a secure, locked in feel. SAFC is in easy reach for some last minute fine tuning. It's a great platform to drive.

 

[silver bullit]

More pics please, it looks almost like the one i used to have.