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please help me understand this

prjacksonau

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hi me an my son both have a vn commodore ss we both have worked motors built by the same bloke except mine has a lot more head work done.
well my queeston is why does my sons car at take off nearly launch me through the rear window an mine is not much more than standard.
can give more specs if sumbody is willing 2 answer this for me
p.s. no we have not have them on the dyno yet.
 

Doctor Bob

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if the heads have been ported heaps more as you have said they may be too big loosing low end torque & need lots of revs to work.

Rob
 

FXST01

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Do they both have the same gearbox/diff?
 

prjacksonau

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yeh same gearbox an diff in both. sons heads where "quote engene builder" just cleaned up not much above standard mine where ported an shaved rated 2 530hp. any1 got any ideas on how 2 get the same low end power as my sons short of a head change.
 

sir355

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put a stroker crank in it!!, but is more than short of a head change
 

prjacksonau

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maybe a ratio change in the diff any1 got any ideas
 

RVN 355

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Tune ECU re programmed to suit all ur mods,timing adjustments,diff gears, compression change
 

sir355

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go 3.9. easy swap, Are you running the auto or manual?
Have you had your car dyno tuned since all the mods?
 

prjacksonau

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nah havent had time 2 get em dynoed yet they are both auto
 

sir355

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mate, there is your problem. Your computer is not tuned to your mods. The tune in your sons is closer as the heads are not flowing as much.
You can't go and do mods to a car and not match your chip to them and hope it is going to go well. Dont buy an off the shelf chip either. Get it dynoed real time by a pro. The difference will be huge!!
Good luck, hope my son enjoys his first car in 17 years!!
 
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