went to the track in the formula
09-29-2015, 01:11 PM
#21
TECH Resident
MPH in the 1/8 looks better. How many miles on it? I would be willing to bet a valve spring change would give you better numbers if there are a lot of miles on the motor.
Last edited by ACE1252; 10-01-2015 at 06:46 AM.
09-29-2015, 01:17 PM
#22
TECH Resident
I'm not sure if they still do this, but Piedmont Dragway here in NC used to do that.....
I would let them go as well. I just didn't want them coming into my lane if something went wrong. Granted, I'd have time to see it given how fast they are, but if I screwed up I'd be plowing into them.
It's impressive they way those cars shake the ground, but unless mine is shaking the ground too....just let'em go.
09-30-2015, 08:46 AM
#24
12 Second Club
Thread Starter
You want to shift where the torque of the current gear * that gear ratio falls below the torque of the next gear at the new shifted rpm * that new gears ratio. What hits the tire is the torque * the transmission gear, and lower gears have higher ratio, so even though you may make 350lb ft at 4000 and 250 at 6000, if 250* old gear is greater than 350* new gear you shifted to early. It's been found, by myself and others, that the stock cam and heads with boltons goes fastest shifted at 6300. It may go faster shifting higher, but stock rod bolts start getting iffy.
Agreed.
I'm not sure if they still do this, but Piedmont Dragway here in NC used to do that.....
I would let them go as well. I just didn't want them coming into my lane if something went wrong. Granted, I'd have time to see it given how fast they are, but if I screwed up I'd be plowing into them.
It's impressive they way those cars shake the ground, but unless mine is shaking the ground too....just let'em go.
I'm not sure if they still do this, but Piedmont Dragway here in NC used to do that.....
I would let them go as well. I just didn't want them coming into my lane if something went wrong. Granted, I'd have time to see it given how fast they are, but if I screwed up I'd be plowing into them.
It's impressive they way those cars shake the ground, but unless mine is shaking the ground too....just let'em go.
Currently the car has pacesetter LTs and ORY into a 'phabmouth' catback, HD2 shift kit, founders rear LCAs, umi front LCAs, ebay CAI, TB bypass, TB airfoil (lol), koni sports on all four corners, and minimal tuning.
for the track I pulled the sway bar completely (it was way lighter than I expected). I also had no spare or jack, emptied the wiper reservoir, swapped my oewheels 17" C5 Z06 replicas for some salad shooters with some Toyo proxes TQs in the rear and some 215s in the front.
Last edited by fbody_brian; 09-30-2015 at 09:38 AM.
09-30-2015, 11:03 AM
#25
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Currently the car has pacesetter LTs and ORY into a 'phabmouth' catback, HD2 shift kit, founders rear LCAs, umi front LCAs, ebay CAI, TB bypass, TB airfoil (lol), koni sports on all four corners, and minimal tuning.
for the track I pulled the sway bar completely (it was way lighter than I expected). I also had no spare or jack, emptied the wiper reservoir, swapped my oewheels 17" C5 Z06 replicas for some salad shooters with some Toyo proxes TQs in the rear and some 215s in the front.
Currently the car has pacesetter LTs and ORY into a 'phabmouth' catback, HD2 shift kit, founders rear LCAs, umi front LCAs, ebay CAI, TB bypass, TB airfoil (lol), koni sports on all four corners, and minimal tuning.
for the track I pulled the sway bar completely (it was way lighter than I expected). I also had no spare or jack, emptied the wiper reservoir, swapped my oewheels 17" C5 Z06 replicas for some salad shooters with some Toyo proxes TQs in the rear and some 215s in the front.
09-30-2015, 12:57 PM
#26
12 Second Club
Thread Starter
One thing i forgot to mention about the car, it's got a 3.42 geared rear from a 02 camaro. I know that's a tiny difference from it's stock 3.23s but I imagine it helps a little.
10-01-2015, 06:52 AM
#27
TECH Resident
Hehe, this is a slippery slope, but if you don't have 1.6 roller rockers, now would be a good time with the spring change. You don't have to get rockers with a roller tip(similar to LS1 style). Just so they have a roller fulcrum and are self aligning in some way. That would give you more lift.
10-02-2015, 08:25 AM
#28
12 Second Club
Thread Starter
last night I was looking at the last tune that I uploaded to the car and it appears that it's set to the stock shift points of something like 5350rpm...
the tach must be way off because it goes above 6k at wot. I figured it was off a little but it's off a good bit. rev limiter was set at like 5850.
I really need to take it out and get some logging done to see when it's actually shifting.
I think these valve springs are shot though. On a few of the runs, right before the 2-3 shift it would pop or misfire then shift. when this happened you could just feel the motor stop pulling for a second.
Springs should be here in a few days (pac-1212x), and I'll probably change the cap and rotor on the opti also, since I've had them just sitting here.
I'm definitely going to get some roller rockers. seriously considering scorpion 1.7s.
the tach must be way off because it goes above 6k at wot. I figured it was off a little but it's off a good bit. rev limiter was set at like 5850.
I really need to take it out and get some logging done to see when it's actually shifting.
I think these valve springs are shot though. On a few of the runs, right before the 2-3 shift it would pop or misfire then shift. when this happened you could just feel the motor stop pulling for a second.
Springs should be here in a few days (pac-1212x), and I'll probably change the cap and rotor on the opti also, since I've had them just sitting here.
I'm definitely going to get some roller rockers. seriously considering scorpion 1.7s.
Last edited by fbody_brian; 10-02-2015 at 10:27 AM.
10-02-2015, 09:29 AM
#29
I was looking at the last tune that I uploaded to the car last night and it appears that it's set to the stock shift points of something like 5350rpm...
the tach must be way off because it goes above 6k at wot. I figured it was off a little but it's off a good bit. rev limiter was set at like 5850.
I really need to take it out and get some logging done to see when it's actually shifting.
I think these valve springs are shot though. On a few of the runs, right before the 2-3 shift it would pop or misfire then shift. when this happened you could just feel the motor stop pulling for a second.
Springs should be here in a few days (pac-1212x), and I'll probably change the cap and rotor on the opti also, since I've had them just sitting here.
I'm definitely going to get some roller rockers. seriously considering scorpion 1.7s.
the tach must be way off because it goes above 6k at wot. I figured it was off a little but it's off a good bit. rev limiter was set at like 5850.
I really need to take it out and get some logging done to see when it's actually shifting.
I think these valve springs are shot though. On a few of the runs, right before the 2-3 shift it would pop or misfire then shift. when this happened you could just feel the motor stop pulling for a second.
Springs should be here in a few days (pac-1212x), and I'll probably change the cap and rotor on the opti also, since I've had them just sitting here.
I'm definitely going to get some roller rockers. seriously considering scorpion 1.7s.
10-03-2015, 08:01 AM
#30
12 Second Club
Thread Starter
Good spring choice. I'll be interested in finding out if the springs help your motor keep from losing power and falling out at the top end. I went to the drag strip one time and this is what my old motor did. However I bought another LT1 with a T56 Trans, rebuilt it and now the old motor with 160k is sitting in my garage... Lol
Last edited by fbody_brian; 10-03-2015 at 08:09 AM.
10-03-2015, 08:54 PM
#31
last night I was looking at the last tune that I uploaded to the car and it appears that it's set to the stock shift points of something like 5350rpm...
the tach must be way off because it goes above 6k at wot. I figured it was off a little but it's off a good bit. rev limiter was set at like 5850.
I really need to take it out and get some logging done to see when it's actually shifting.
I think these valve springs are shot though. On a few of the runs, right before the 2-3 shift it would pop or misfire then shift. when this happened you could just feel the motor stop pulling for a second.
Springs should be here in a few days (pac-1212x), and I'll probably change the cap and rotor on the opti also, since I've had them just sitting here.
I'm definitely going to get some roller rockers. seriously considering scorpion 1.7s.
the tach must be way off because it goes above 6k at wot. I figured it was off a little but it's off a good bit. rev limiter was set at like 5850.
I really need to take it out and get some logging done to see when it's actually shifting.
I think these valve springs are shot though. On a few of the runs, right before the 2-3 shift it would pop or misfire then shift. when this happened you could just feel the motor stop pulling for a second.
Springs should be here in a few days (pac-1212x), and I'll probably change the cap and rotor on the opti also, since I've had them just sitting here.
I'm definitely going to get some roller rockers. seriously considering scorpion 1.7s.
I got a laugh out of that. Normally a power loss is associated with a backfire or missfire lol, did it sound like you were hitting the limiter at all?
I would do 1.6's. Scorpions are pretty good. The reason I would do 1.6 over 1.7 is because if you get a camshaft down the road you can reuse your 1.6's. Also I beleive the power gain from 1.6 to 1.7's is not near as big as 1.5's to 1.6's. I believe you should get around 12rwhp from 1.5 to 1.6's.
10-03-2015, 09:53 PM
#32
12 Second Club
Thread Starter
yeah, guess you're right. duh.
now that I think about it that was a pretty dumb statement.don't actually know that it was valve float, but it was just like a miss or something, slight pop and then it would shift.
It definitely wasn't on the limiter, I know what that feels like. Plenty experience when my trans went out before
It does feel like it just is lacking power in the upper rpms though. just like it stops pulling.
regardless new springs will be here monday.
10-03-2015, 10:10 PM
#33
Actually lt1-xjs is making some pretty good power with a stock cam and 1.7s but Trilkb is right they won't be much good down the road on a cam change. I'm running pac1212x springs on my hotcam and am very happy with them but they are rather limited on the lift they can handle before coil bind.
Last edited by guppymech; 10-04-2015 at 12:28 AM.
10-04-2015, 10:58 AM
#34
12 Second Club
Thread Starter
Actually lt1-xjs is making some pretty good power with a stock cam and 1.7s but Trilkb is right they won't be much good down the road on a cam change. I'm running pac1212x springs on my hotcam and am very happy with them but they are rather limited on the lift they can handle before coil bind.
I figure that if I ever want a bigger cam I can try to have one specced for 1.7 rockers. I'm not really trying to go really big on a cam anyway. Something like a 227 or a 502 would suite me fine.
Last edited by fbody_brian; 10-04-2015 at 11:23 AM.
10-04-2015, 01:35 PM
#35
Amen to that... I did a 503, and honestly yeah it's awesome and sounds good but I almost feel somewhere in the future I will de-cam the motor to something a little more smaller.
10-04-2015, 04:29 PM
#36
I really want to give the 227 a try but its one expensive bastard! 490$ for it on jegs and summit! A hot cam kit is 595 and it comes with rockers and springs for an extra 105$.
it does look like another 10hp may be in there from 1.6 to 1.7's...~20rwhp from rockers is a damn good increase! I thought I read awhile back the increase from 1.6 to 1.7 was like 3-5 hp. Now you got my interested in the 1.7's. Gotta do springs if I do 1.6's anyways. I wonder how well the computer can take care of tuning on the 1.7's.
it does look like another 10hp may be in there from 1.6 to 1.7's...~20rwhp from rockers is a damn good increase! I thought I read awhile back the increase from 1.6 to 1.7 was like 3-5 hp. Now you got my interested in the 1.7's. Gotta do springs if I do 1.6's anyways. I wonder how well the computer can take care of tuning on the 1.7's.
Last edited by trilkb; 10-04-2015 at 04:38 PM.
10-04-2015, 09:23 PM
#37
12 Second Club
Thread Starter
I really want to give the 227 a try but its one expensive bastard! 490$ for it on jegs and summit! A hot cam kit is 595 and it comes with rockers and springs for an extra 105$.
it does look like another 10hp may be in there from 1.6 to 1.7's...~20rwhp from rockers is a damn good increase! I thought I read awhile back the increase from 1.6 to 1.7 was like 3-5 hp. Now you got my interested in the 1.7's. Gotta do springs if I do 1.6's anyways. I wonder how well the computer can take care of tuning on the 1.7's.
it does look like another 10hp may be in there from 1.6 to 1.7's...~20rwhp from rockers is a damn good increase! I thought I read awhile back the increase from 1.6 to 1.7 was like 3-5 hp. Now you got my interested in the 1.7's. Gotta do springs if I do 1.6's anyways. I wonder how well the computer can take care of tuning on the 1.7's.
I'm excited to see how the 1.7s do. it'll put my lift numbers right at .510/.521.
all the stuff will be here monday and tuesday. won't accomplish anything this week though, Cruisin the coast is here!
10-06-2015, 08:29 AM
#39
12 Second Club
Thread Starter