shelbypowered Posted November 18, 2007 Report Share Posted November 18, 2007 :happy feet: running gt 500 with 373s and evolstage one inductin- steeda shifter and nitto 26 in radials- problem being I run out of power in third gear and when I shift to fourth I do not have enough power to get mph and et down- with stock gears and same mods I went through thr trap a a bout 117 and 12-4s--with 373s have lost about 6-10 miles an hour and ttwo to three tenths- anyone else have this problem? the 373s are much more agreesive but run out of gear in third about 80 to 100 ft of trap. Nitto makes a 28 inch tall tire which may give me more gear but the tire is tall and uglgy on a gt 500. Give me heck guys if I am not thinking straight as I would like to know how many people are running my comb0- on the steet the 373s are awesome but not so great for me at the trak. Link to comment Share on other sites More sharing options...
trichie Posted November 18, 2007 Report Share Posted November 18, 2007 :happy feet: running gt 500 with 373s and evolstage one inductin- steeda shifter and nitto 26 in radials- problem being I run out of power in third gear and when I shift to fourth I do not have enough power to get mph and et down- with stock gears and same mods I went through thr trap a a bout 117 and 12-4s--with 373s have lost about 6-10 miles an hour and ttwo to three tenths- anyone else have this problem? the 373s are much more agreesive but run out of gear in third about 80 to 100 ft of trap. Nitto makes a 28 inch tall tire which may give me more gear but the tire is tall and uglgy on a gt 500. Give me heck guys if I am not thinking straight as I would like to know how many people are running my comb0- on the steet the 373s are awesome but not so great for me at the trak. Go to 4:10s Link to comment Share on other sites More sharing options...
shelbypowered Posted November 18, 2007 Author Report Share Posted November 18, 2007 Just race it on the street. Link to comment Share on other sites More sharing options...
shelbypowered Posted November 18, 2007 Author Report Share Posted November 18, 2007 thats a good idea not very wise however- rather spend 20.00 for a test and tune at the track than a reckless driving ticket and negligent driving ticket- not that I do not play on the street I just hit short spurts and back off. Racing on the street is not an option- need tech help from other similar setups- do not want to change the forrum by off the cuff remarks-lots of people street race but hthe track on test and tune is the way to learn- thanks though I know you meant wee and thank you for reading the post Link to comment Share on other sites More sharing options...
68fastback Posted November 18, 2007 Report Share Posted November 18, 2007 I guess I'm not understanding what you mean by running out of power with 3.73's Are you hitting the rev-limiter? Do you mean it's just not pulling as hard with the 3.373s in 3rd and 4th? We're you shifting at the same rpm with the stock gears? (if both of these are true, it sounds like a fuel restriction or some sort ...if I'm not misunderstanding you). What rpm are you going thru the traps at in 4th with the 3.73s. What about with the stock gears, etc? Btw, WELCOME TO SU!!!! Dan Link to comment Share on other sites More sharing options...
regalt87 Posted November 18, 2007 Report Share Posted November 18, 2007 I think if you step up to stage 2, you would keep pulling. Link to comment Share on other sites More sharing options...
svtbird91 Posted November 18, 2007 Report Share Posted November 18, 2007 I'm asuming that you mean you are reaching red line 80 - 100 feet before the line ,how about using 4th ? maybe shift from 3rd at 6000rpm. Link to comment Share on other sites More sharing options...
SVTpower Posted November 18, 2007 Report Share Posted November 18, 2007 I'm asuming that you mean you are reaching red line 80 - 100 feet before the line ,how about using 4th ? maybe shift from 3rd at 6000rpm. +1 You're holding 3rd just a bit too long........go to fourth, you'll see both mph and et improvement Link to comment Share on other sites More sharing options...
Justin00Stang Posted November 18, 2007 Report Share Posted November 18, 2007 I had that problem too, stock tires + tune with 250rpm raised rev limit, I could go through traps in 3rd at just over 116mph on the limiter. With a pulley I had to shift just before the end, and with smaller DRs on the back the issue was compounded even more, and I had stock gears. Just practice on getting down the track and making a quick 3-4 shift. More power will help too. Link to comment Share on other sites More sharing options...
shelbypowered Posted November 19, 2007 Author Report Share Posted November 19, 2007 that is correct I would hit the rev limitor just before trap in third- stock gears took me through trap easily in third gear at higher mph the 373s launch better and there is a good horsepowe gain from 1-3 it just that I am within 80-100 ft of the trap when the rev limitor hits- need to get into 4th a little sooner so I can gain pulling power- being so close to the trap in 3rd it loses rpm and power because of the time to shift and try to accelerate-Imay well be almost coasting through the trap in fourth. anyone else running 373s and checking shift points? Link to comment Share on other sites More sharing options...
kaylan1521 Posted November 19, 2007 Report Share Posted November 19, 2007 With stock gears I am using fourth and trapping at 118. Stage 1 1/2 in my car. Actually stage 2 without the idler so I'm only making +2 #'s of boost. Anycase, with 3.73's you should most definitely be hitting fourth and still making steam as you cross the stripe. If you're trying to run out the back in third gear you will definitely slow down as you'll be hitting the limiter and at those speeds when you do hit the limiter it will easily take 4+mph off your trap speed. Your other option is to short shift second to third by just a bit which will get you into fourth sooner Link to comment Share on other sites More sharing options...
BADBOY500 Posted November 19, 2007 Report Share Posted November 19, 2007 28" tires for the track and run the 26" on the street............best of both worlds, but you will need a set of rims for the track. Link to comment Share on other sites More sharing options...
VNMOUS1 Posted November 19, 2007 Report Share Posted November 19, 2007 :happy feet: running gt 500 with 373s and evolstage one inductin- steeda shifter and nitto 26 in radials- problem being I run out of power in third gear and when I shift to fourth I do not have enough power to get mph and et down- with stock gears and same mods I went through thr trap a a bout 117 and 12-4s--with 373s have lost about 6-10 miles an hour and ttwo to three tenths- anyone else have this problem? the 373s are much more agreesive but run out of gear in third about 80 to 100 ft of trap. Nitto makes a 28 inch tall tire which may give me more gear but the tire is tall and uglgy on a gt 500. Give me heck guys if I am not thinking straight as I would like to know how many people are running my comb0- on the steet the 373s are awesome but not so great for me at the trak. 12.19 @ 122.74 with traction control ON 3.73's. Stock (read: crap) tires. 80 degree day @ 650 msl altitude If I lost 10 mph because of my 3.73s, I'd be a friggin' rocket. 122 mph is low to mid 11's if I could hook. Your 3.73s aren't the problem. bj Link to comment Share on other sites More sharing options...
FordGeek Posted November 19, 2007 Report Share Posted November 19, 2007 Seems to me you just need to adjust your shifting habits to your tune and gears. When I was stock I was running pretty much like the rest of the bunch here. Popped in 4.10s and the Kenne Bell stage 3 and, holy crap, I'm at redline in 4th gear and shifting like my life depended on it! But who cares, I run high tens all day long and go home with the radio blasting and the AC running on high. Now, there are some times when the tune and gear combo don't quite jive due to the fact that that the torque curve shifts way to the left and what you get is a gobs of pull down low and a quick tapering off at the top end. This is typical of the Eatons and other grass roots blowers and you simply have to play with your combo until it responds the way you'd like. It's just like the whole aftermarket exhaust thing. Some folks with blowers get the biggest nastiest exhaust they can get; but in the process they lose the required back pressue to get good boost out of their huffers. The result, they think that something is wrong fundamentally with their car. But, no, it's just their combo. Link to comment Share on other sites More sharing options...
68fastback Posted November 19, 2007 Report Share Posted November 19, 2007 Is a "grass roots blower" a rock-band groupie from the 60/70s? <sorry, just kiddin', Joseph ...got stuck on that > Link to comment Share on other sites More sharing options...
wickedGT500 Posted November 20, 2007 Report Share Posted November 20, 2007 12.19 @ 122.74 with traction control ON 3.73's. Stock (read: crap) tires. 80 degree day @ 650 msl altitude If I lost 10 mph because of my 3.73s, I'd be a friggin' rocket. 122 mph is low to mid 11's if I could hook. Your 3.73s aren't the problem. bj +1 Link to comment Share on other sites More sharing options...
FordGeek Posted November 20, 2007 Report Share Posted November 20, 2007 Is a "grass roots blower" a rock-band groupie from the 60/70s? <sorry, just kiddin', Joseph ...got stuck on that > No, those would be the Hummer H-ooohs! Link to comment Share on other sites More sharing options...
68fastback Posted November 20, 2007 Report Share Posted November 20, 2007 ...exactly... ...so how's the-first-GT500-to-post-a-dyno-chart-on-SU doing these days? Are you having and TB sticking problems on your KB stage-3? Gotta be an awesome experience!!!!!! Dan Link to comment Share on other sites More sharing options...
shelbypowered Posted November 20, 2007 Author Report Share Posted November 20, 2007 +1 You're holding 3rd just a bit too long........go to fourth, you'll see both mph and et improvementI hope your right- you have 373s so you must know- with stock gears through the trap in third at 115 373s hit the reve limitor just short of trap- what rpms do you shift at - I thought it was correct to get as much r[m out of each gear - try to reach power point before itr stops pulling or before rev limitor goes on Link to comment Share on other sites More sharing options...
Secondo Posted November 20, 2007 Report Share Posted November 20, 2007 My advice from an experienced dragracer and from what I've been learning from GT500 owners here: Try this: You yourself be in fully rested condition for maximum reflexes and minimum reaction time. Keep 3.73's. Get rear wheels with 26" slicks. Turn traction control off. Launch at around 4500 RPM or as much as you can get away with depending on conditions. 1st-2nd shift at redline. 2nd-3rd shift 6250 3rd-4th 6000 Don't granny shift and keep the Pedal to the Metal!! Link to comment Share on other sites More sharing options...
Shelby3 Posted November 20, 2007 Report Share Posted November 20, 2007 :happy feet: running gt 500 with 373s and evolstage one inductin- steeda shifter and nitto 26 in radials- problem being I run out of power in third gear and when I shift to fourth I do not have enough power to get mph and et down- with stock gears and same mods I went through thr trap a a bout 117 and 12-4s--with 373s have lost about 6-10 miles an hour and ttwo to three tenths- anyone else have this problem? the 373s are much more agreesive but run out of gear in third about 80 to 100 ft of trap. Nitto makes a 28 inch tall tire which may give me more gear but the tire is tall and uglgy on a gt 500. Give me heck guys if I am not thinking straight as I would like to know how many people are running my comb0- on the steet the 373s are awesome but not so great for me at the trak. You can play with this graph to show different alternatives like gears or tires and figure out your trap speed. Good luck. Please note that this is an Excel file. I changed the file extension to .doc so I can upload. Once you download the file just change the extension back to.xls so you can open it properly.Speed_vs_RPM.doc Speed_vs_RPM.doc Link to comment Share on other sites More sharing options...
iceman Posted November 20, 2007 Report Share Posted November 20, 2007 :happy feet: running gt 500 with 373s and evolstage one inductin- steeda shifter and nitto 26 in radials- problem being I run out of power in third gear and when I shift to fourth I do not have enough power to get mph and et down- with stock gears and same mods I went through thr trap a a bout 117 and 12-4s--with 373s have lost about 6-10 miles an hour and ttwo to three tenths- anyone else have this problem? the 373s are much more agreesive but run out of gear in third about 80 to 100 ft of trap. Nitto makes a 28 inch tall tire which may give me more gear but the tire is tall and uglgy on a gt 500. Give me heck guys if I am not thinking straight as I would like to know how many people are running my comb0- on the steet the 373s are awesome but not so great for me at the trak. Use 4th gear. I am trapping 130+ with 373's and 26" ET Streets but have to use 4th and push it right to the end as you are close to the limiter with the KB and this set up if you don't bump the limiter up a bit. once you get away from the 331's you are going to need to use 4th gear though - that's why you are running out of gear in 3rd and have a lower mph. Adjust shift points accordingly and use 4th - problem solved. Link to comment Share on other sites More sharing options...
jcthorne Posted November 20, 2007 Report Share Posted November 20, 2007 :happy feet: running gt 500 with 373s and evolstage one inductin- steeda shifter and nitto 26 in radials- problem being I run out of power in third gear and when I shift to fourth I do not have enough power to get mph and et down- with stock gears and same mods I went through thr trap a a bout 117 and 12-4s--with 373s have lost about 6-10 miles an hour and ttwo to three tenths- anyone else have this problem? the 373s are much more agreesive but run out of gear in third about 80 to 100 ft of trap. Nitto makes a 28 inch tall tire which may give me more gear but the tire is tall and uglgy on a gt 500. Give me heck guys if I am not thinking straight as I would like to know how many people are running my comb0- on the steet the 373s are awesome but not so great for me at the trak. Wanna swap your 3.73s for my 4.10s? Link to comment Share on other sites More sharing options...
FordGeek Posted November 20, 2007 Report Share Posted November 20, 2007 ...exactly... ...so how's the-first-GT500-to-post-a-dyno-chart-on-SU doing these days? Are you having and TB sticking problems on your KB stage-3? Gotta be an awesome experience!!!!!! Dan TB sticking problems?! Where did you hear that? Hopefully it's isolated as my setup has been running just fine. I do have a bit of a traction problem when driving around on the stock meats, but I've trained my right leg to apply just the right amount of pedal pressure throughout the rpm range; it's a science you know ;-) Also, I've been having a bit of a problem with rough idle at startup; seems to run rich as heck until the O2 sensors get up to temp; thought it might have been a dirty filter, but after cleaning I'm still having the same issue. Also, tested all of the electronic components like the boost-a-pump, but even it was running at a clean 17 volts. Doesn't really bother me given that real-time data logging reveals nothing of importance and she pulls like she should once she's warmed up. It has been, nevertheless, a blast to drive since adding the KB...Hope things are well with you... Regards, Joseph (FordGeek) Link to comment Share on other sites More sharing options...
68fastback Posted November 20, 2007 Report Share Posted November 20, 2007 TB sticking problems?! Where did you hear that? Hopefully it's isolated as my setup has been running just fine. I do have a bit of a traction problem when driving around on the stock meats, but I've trained my right leg to apply just the right amount of pedal pressure throughout the rpm range; it's a science you know ;-) Also, I've been having a bit of a problem with rough idle at startup; seems to run rich as heck until the O2 sensors get up to temp; thought it might have been a dirty filter, but after cleaning I'm still having the same issue. Also, tested all of the electronic components like the boost-a-pump, but even it was running at a clean 17 volts. Doesn't really bother me given that real-time data logging reveals nothing of importance and she pulls like she should once she's warmed up. It has been, nevertheless, a blast to drive since adding the KB...Hope things are well with you... Regards, Joseph (FordGeek) Sounds like a blast!!! I had heard there were some s-3 TB sticking problems -- maybe that's been 'cured' now ;-) If I recall, the KB strage-3 uses some sort of MAF scaling device to 'fool' the ECU by scaling the voltage from the MAF back to the ECU to fit the enhanced air flow into the ECU's 5.0 volt sensor range. If they are still doing it that way (dunno) that could account for warm up and low-speed balkiness. I've heard of plenty of '03/04 Cobras using MAF signal-scalers having similar problems but not sure how KB handles that. Joseph, do you have any idea what rail-pressure the boost-a-pumps provide at 17 volts? KB must tweak some ECU parameters for a higher rail-pressure so the ECU doesn't just cycle the pumps less often to maintain the stock line pressure (39-40#??). Are you running the KB-provided tune or an Evo/custom tune? Dan Link to comment Share on other sites More sharing options...
FordGeek Posted November 25, 2007 Report Share Posted November 25, 2007 Sounds like a blast!!! I had heard there were some s-3 TB sticking problems -- maybe that's been 'cured' now ;-) If I recall, the KB strage-3 uses some sort of MAF scaling device to 'fool' the ECU by scaling the voltage from the MAF back to the ECU to fit the enhanced air flow into the ECU's 5.0 volt sensor range. If they are still doing it that way (dunno) that could account for warm up and low-speed balkiness. I've heard of plenty of '03/04 Cobras using MAF signal-scalers having similar problems but not sure how KB handles that. Joseph, do you have any idea what rail-pressure the boost-a-pumps provide at 17 volts? KB must tweak some ECU parameters for a higher rail-pressure so the ECU doesn't just cycle the pumps less often to maintain the stock line pressure (39-40#??). Are you running the KB-provided tune or an Evo/custom tune? Dan Yes, it uses the DiabloSport mass air extender. It needs it because the volume of air the large throttle body sucks in causes the stock mass air to top off prematurely (wow, that sounds odd). When it does that the ECU pulls fuel thinking it's getting too much air; the result is detonation. Most custom tunes for CAIs will maximize the mass air curves to prevent it from completely blowing up the engine. However, throw in a throttle body and there's no way to do this via a tune; hence the extender and ECU tune combo. I'm using the stock KB tune given that it runs safely and has more than enough power for this lunatic. So, good question with regard to line pressures. Link to comment Share on other sites More sharing options...
BADBOY500 Posted November 25, 2007 Report Share Posted November 25, 2007 Sounds like a blast!!! I had heard there were some s-3 TB sticking problems -- maybe that's been 'cured' now ;-) If I recall, the KB strage-3 uses some sort of MAF scaling device to 'fool' the ECU by scaling the voltage from the MAF back to the ECU to fit the enhanced air flow into the ECU's 5.0 volt sensor range. If they are still doing it that way (dunno) that could account for warm up and low-speed balkiness. I've heard of plenty of '03/04 Cobras using MAF signal-scalers having similar problems but not sure how KB handles that. Joseph, do you have any idea what rail-pressure the boost-a-pumps provide at 17 volts? KB must tweak some ECU parameters for a higher rail-pressure so the ECU doesn't just cycle the pumps less often to maintain the stock line pressure (39-40#??). Are you running the KB-provided tune or an Evo/custom tune? Dan.. I have seen mine spike at 85 to 90 psi [70 ish at wot] if my memory serves me right... Link to comment Share on other sites More sharing options...
svtbird91 Posted November 25, 2007 Report Share Posted November 25, 2007 Yes, it uses the DiabloSport mass air extender. It needs it because the volume of air the large throttle body sucks in causes the stock mass air to top off prematurely (wow, that sounds odd). When it does that the ECU pulls fuel thinking it's getting too much air; the result is detonation. Most custom tunes for CAIs will maximize the mass air curves to prevent it from completely blowing up the engine. However, throw in a throttle body and there's no way to do this via a tune; hence the extender and ECU tune combo. I'm using the stock KB tune given that it runs safely and has more than enough power for this lunatic. So, good question with regard to line pressures. It's because of the DS mass air extender and the KB boost-a-pumps I will not be choosing the KB setup anytime soon. Call me old school but I believe the only way to go is with a properly calibrated mass air meter used in conjunction with larger fuel injectors , fuel pumps and lines. Trying to get around this by "fooling " the computer's actual air flow and boosting voltage to the pumps is a back door approch IMO. Link to comment Share on other sites More sharing options...
68fastback Posted November 26, 2007 Report Share Posted November 26, 2007 I have seen mine spike at 85 to 90 psi [70 ish at wot] if my memory serves me right... Big increase! Thanks, Dave. ...at 70psi an injector calibrated for nn #fuel/hr at 39-40psi (which I think FRP uses as a calibration default if I recall) will flow a lot more than nn, but would seem to push the engineering envelope quite a bit. Link to comment Share on other sites More sharing options...
shelbypowered Posted December 4, 2007 Author Report Share Posted December 4, 2007 My advice from an experienced dragracer and from what I've been learning from GT500 owners here:Try this: You yourself be in fully rested condition for maximum reflexes and minimum reaction time. Keep 3.73's. Get rear wheels with 26" slicks. Turn traction control off. Launch at around 4500 RPM or as much as you can get away with depending on conditions. 1st-2nd shift at redline. 2nd-3rd shift 6250 3rd-4th 6000 Don't granny shift and keep the Pedal to the Metal!! Link to comment Share on other sites More sharing options...
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