I'm going crazy figuring out why my car is so weak!
#1
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I'm going crazy figuring out why my car is so weak!
My mods are:
Vortech with 2.87 pulley
DW 550cc injectors
AAM Stage 1 Fuel Return
Walbro fuel pump
Skunk2 Plenum Spacer
Megan Racing longtube headers
Ebay "Nismo" replica exhaust with cutout.
My car is a 2003 G35 5AT w/ 80K miles ( 5K on the Vortech ) and it has 20" wheels ( rear wheel + tires weigh over 60lbs ).
Yesterday I went to the dyno and tuned my new setup ( the 2.87 pulley and AAM fuel return ). The tune came out beautiful, AF was flat at 11.4/11.5 and timing was in the 18-19* range with no knock. Boost would go to 11psi at redline.
The problem is that I only put down 367whp on a DJ. I don't have the graph with me but it was SUPER smooth ( even with smoothing at 0 ) and was very straight ( no dips and no fall off ). Just imagine the most beautiful Vortech dyno graph...at only 367whp.
My car has absolutely no blow by ( very little at WOT and no oil is coming out ) and runs and pulls great...just underpowered. Could my engine be bad without it showing signs of being bad?
What could be wrong? Some people say my 20's are killing me but could I lose 40-60whp from my 20's? I need ideas?
Vortech with 2.87 pulley
DW 550cc injectors
AAM Stage 1 Fuel Return
Walbro fuel pump
Skunk2 Plenum Spacer
Megan Racing longtube headers
Ebay "Nismo" replica exhaust with cutout.
My car is a 2003 G35 5AT w/ 80K miles ( 5K on the Vortech ) and it has 20" wheels ( rear wheel + tires weigh over 60lbs ).
Yesterday I went to the dyno and tuned my new setup ( the 2.87 pulley and AAM fuel return ). The tune came out beautiful, AF was flat at 11.4/11.5 and timing was in the 18-19* range with no knock. Boost would go to 11psi at redline.
The problem is that I only put down 367whp on a DJ. I don't have the graph with me but it was SUPER smooth ( even with smoothing at 0 ) and was very straight ( no dips and no fall off ). Just imagine the most beautiful Vortech dyno graph...at only 367whp.
My car has absolutely no blow by ( very little at WOT and no oil is coming out ) and runs and pulls great...just underpowered. Could my engine be bad without it showing signs of being bad?
What could be wrong? Some people say my 20's are killing me but could I lose 40-60whp from my 20's? I need ideas?
Last edited by GT-ER; 07-02-2010 at 02:10 PM.
#3
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Well wheels/tires that heavy are certainly stealing power getting to the ground. How much is hard to say. But I know it can be a lot, especially if they are that heavy.
Anyone have wheels you can borrow to try with something lighter?
Tom
Anyone have wheels you can borrow to try with something lighter?
Tom
#6
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I know when the big dogs put on ET-Streets to dyno on (like 15in wheel with 26in tire), with all that weight they give up a lot of power.......but they need it to stay on dyno.
How much do your fronts weigh? Maybe swap them to rear.
Tom
How much do your fronts weigh? Maybe swap them to rear.
Tom
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#10
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It not your wheels. your AIT's look perfect. timing is fairly aggressive.
if your car is mechanically sound, good compression/leakdown, then you just have a weak motor from the start, combined with an automatic transmission = lower than avg #'s
I'd say it could also be a miscalibrated dyno, but your trap times are awful as well.
if your car is mechanically sound, good compression/leakdown, then you just have a weak motor from the start, combined with an automatic transmission = lower than avg #'s
I'd say it could also be a miscalibrated dyno, but your trap times are awful as well.
#12
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367whp is not too far off the mark We just tuned a 6sp G35 2.87 vortech car and made 428whp, he was running 20's and was tune on a 90 degree day. We have found that the Auto cars make about 10-12% less power then the 6sp cars...so when ya do the math its not too bad...
#13
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It not your wheels. your AIT's look perfect. timing is fairly aggressive.
if your car is mechanically sound, good compression/leakdown, then you just have a weak motor from the start, combined with an automatic transmission = lower than avg #'s
I'd say it could also be a miscalibrated dyno, but your trap times are awful as well.
if your car is mechanically sound, good compression/leakdown, then you just have a weak motor from the start, combined with an automatic transmission = lower than avg #'s
I'd say it could also be a miscalibrated dyno, but your trap times are awful as well.
367whp is not too far off the mark We just tuned a 6sp G35 2.87 vortech car and made 428whp, he was running 20's and was tune on a 90 degree day. We have found that the Auto cars make about 10-12% less power then the 6sp cars...so when ya do the math its not too bad...
#17
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What do u expect from an AT? Also u need to post your dyno with the boost level. I want to see when u are hitting 11psi and if it's really staying at 11psi at wot.
Also, check your blower to make sure its not taking a dump. U can always upgrade to a S trim for 500 more or T trim for 1300 more.
Also, check your blower to make sure its not taking a dump. U can always upgrade to a S trim for 500 more or T trim for 1300 more.
Last edited by Mr_pharmD; 07-01-2010 at 10:59 PM.
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What do u expect from an AT? Also u need to post your dyno with the boost level. I want to see when u are hitting 11psi and if it's really staying at 11psi at wot.
Also, check your blower to make sure its not taking a dump. U can always upgrade to a S trim for 500 more or T trim for 1300 more.
Also, check your blower to make sure its not taking a dump. U can always upgrade to a S trim for 500 more or T trim for 1300 more.
Last time I checked the blower inlet it looked fine, don't know about the impellers exducer though...I'd have to remove the blower to find out. I'd probably get a 928 impeller if it were screwed up though.
Last edited by GT-ER; 07-02-2010 at 04:00 AM.
#20
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You're right, but it really makes me wonder where the power is going because something HAS to be wrong to be so underpowered. But if all checks out then I can live with 360whp.