I need help in my 3.73

[jalal96]

Hello all,


At the beginning I want to introduce my self,, My name is Jalal, 27 years old, from KSA, My car is a Holden Monaro 2003 but bought from Chevrolet named Lumina SS ( LS1 engine ).

I'm facing some problems in may car performance, which I feel that my car is not what it should be,,, when it was stock, it was so bad in performance,, and then I've installed a shift kit with gear cooler, engine pulley set, K&N air filter and reprogrammed my car,,, after that my car became a different car,,, it was getting from 0-100 Km/h in 7 Sec, but after what I've done I can get from 0 to 100 km/h in about 5.6 Sec which is a big deference,,,,, Still this is not my problem,,, My problem comes now,,, when I bought a differential with 3.73 ratio with limited slip and reprogrammed my car to have the 3.73 ratio,,,, now all what I feel is that my car changing gears faster and the RPM is always high, two wheel drive and still NO feeling to any increase in performance,,, still I get from 0-100 in 5.6 Sec ,,,, also before I was able to reach 210~220 km/h in a distance of 700 meters and now I can get only 200 km/h,,, my friends still can catch up with me with their 3.08 differential !!!!


I don't know what is the problem,,, is it in the differential or in the car program,,, or what ???

I hope that you can help me in this

Thanks and best regards,

Jalal

[Sarge]

Welcome Jalal......
Yes your problem lies in shift points....they must be "tuned" to match your new gears....sounds to me like the old shift points are causing your engine to lug and not be in the power RPM band.....
There are many solutions....handheld programmers can custom program your car with your new gears to match the power bands and shift points.....ship the program to you for flash programming......
If you have a dyno in your area I recommend dyno tuning to maximize the power/gear ratio setup.......
If not some great LS1 handheld custom tuners can be found.....Send this guy an email and tell him what you are after....I know of many who swear by his custom tunes... http://www.runninwiththedevil.com/
And check out some of our sponsors here on the board....I believe some of them may be able to help you.....

[jalal96]

Mmmm, I thought that too,, so last night I went to the guy who installed every thing for me and told him about my story,,, next Saturday I will reprogram my car,,, by the way I had two programs on my car the last one was perfect but before I get the 3.73 and when I got the 3.73 I changed the program to another one and we put in it the 3.73 configuration,,, I think that this new program is not good as the old one,,, so I will put back the old program and put the configuration for the 3.73 ,,,, also there is one thing I forgot to tell you,,, I'm using new tiers ( slick street ) and we didn't enter the new numbers for the tiers sizes,,, so I will also return the old tiers.

One more thing ,,, I'm the first one in my area who put 3.73,,, and I don't really know what performance should I get from it,,, would you please give me some information on what benefit should I get from this 3.73 than my old 3.08 with some examples???

Thanks for your fast replay to me,,, I really appreciate your help

Best regards

[Sarge]

Mmmm, I thought that too,, so last night I went to the guy who installed every thing for me and told him about my story,,, next Saturday I will reprogram my car,,, by the way I had two programs on my car the last one was perfect but before I get the 3.73 and when I got the 3.73 I changed the program to another one and we put in it the 3.73 configuration,,, I think that this new program is not good as the old one,,, so I will put back the old program and put the configuration for the 3.73 ,,,, also there is one thing I forgot to tell you,,, I'm using new tiers ( slick street ) and we didn't enter the new numbers for the tiers sizes,,, so I will also return the old tiers.

One more thing ,,, I'm the first one in my area who put 3.73,,, and I don't really know what performance should I get from it,,, would you please give me some information on what benefit should I get from this 3.73 than my old 3.08 with some examples???

Thanks for your fast replay to me,,, I really appreciate your help

Best regards

Yes...you most defiantly need to tune or "Dial In" your setup properly....
Guys here who have installed the 3.73's in the GTO's are reporting 4-5 MPH quicker trap speeds in the 1/4 mile....say a couple of tenths off of their times....engine stays in the RPM sweet spot much better....shorter shift points keep you in the power band longer......and for cruising many say they enjoy the engine being out of the "drone" zone ......seems to be a great low end torque producing mod...let us know after your tune where you are at with your project.....

[jalal96]

Last night I've put back my tiers that had it sizes correctly in the car program and it really made a very big change, my next step is to try my old program that I feel it's better than the one I'm using now,, by the way,, I feel my car multiplying the tq put down to the wheels and toping out at much lower speed ( from 230 to 200 ) ,, and I think my car will do better when I change to my old program.
Any way thank you very much for your help, I will let you know about my car when I put back my old program on Saturday