Anyone have b4/aftr 3.27 ET

Drivetrain discussion including Transmission, Differential, Driveshaft, and related items.
Numbah1
Posts: 75
Joined: Sun Jan 27, 2019 9:45 pm

Anyone have b4/aftr 3.27 ET

Post by Numbah1 »

In the spring ill get a 3.27 but id like to know what to expect for lowering ET. If i have to go thru all 106 topics to find a before & after time slip i will. Seen on the fb page someone said .2 lower but i cant find that comment now
Turbopowered68
Posts: 141
Joined: Wed Nov 04, 2020 7:09 pm

Re: Anyone have b4/aftr 3.27 ET

Post by Turbopowered68 »

and while you at it post up the same info for the 3.45????
2014 Caprice V8
Elgin E-1840 P, LS9 Head gasket, LS7 Lifters, PAC-1218 springs, Trunion upgrade, Single roller timing set, Melling oil pump, ZL1 torque converter, Camaro Trans pan and filter.
1986 GN
212/212 Roller cam, 1.65 HR Rockers, 60-1 turbo, XFI 2.05, E85, Ebay Front mount IC, Husek Built TH200-4R trans, 3.42 gears 3800# .
1968 Chevelle
LQ4, 4L80, 12 bolt w/3.42 gears
Numbah1
Posts: 75
Joined: Sun Jan 27, 2019 9:45 pm

Re: Anyone have b4/aftr 3.27 ET

Post by Numbah1 »

Why? Everyone says it marginal between 3.27 & 3.45 but never have data for 2.92 vs either
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kevink
Posts: 480
Joined: Sun Aug 09, 2015 12:55 pm

Re: Anyone have b4/aftr 3.27 ET

Post by kevink »

I may have data soon from switching 3.45s to 3.91s. i realize this does not help you out at all...
2011 9C3: 11.48 @118.
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kevink
Posts: 480
Joined: Sun Aug 09, 2015 12:55 pm

Re: Anyone have b4/aftr 3.27 ET

Post by kevink »

Numbah1 wrote: Sun Nov 29, 2020 7:25 pm Why? Everyone says it marginal between 3.27 & 3.45 but never have data for 2.92 vs either
There's not a whole lot of drag racers here.
2011 9C3: 11.48 @118.
BarryM
Posts: 51
Joined: Sun Jul 05, 2020 12:29 am

Re: Anyone have b4/aftr 3.27 ET

Post by BarryM »

kevink wrote: Sun Nov 29, 2020 9:18 pm I may have data soon from switching 3.45s to 3.91s. i realize this does not help you out at all...
Nice !

I was thinking the same thing. I currently have 3.27's,
Best sixty foot has been 1.68

BUT - I read an article/forum post that one of my 5th gen Camaro buddies sent me.
In summary it said (and supported) when N/A and using 6L80 transmission 3.91's left some performance on the table.
4.10's allowed proper(full) use of 4th gear.

Granted, this was Camaro based. But it really got me thinking.
With my full weight car and no signs of spinning yet with Hoosier drag radials I may go 4.10's over the winter.

I am not as fast as you Kevin (12.1 best ET) so you may have a power adder or lighter . . . but I thought I would share for all.
Turbopowered68
Posts: 141
Joined: Wed Nov 04, 2020 7:09 pm

Re: Anyone have b4/aftr 3.27 ET

Post by Turbopowered68 »

I read this a few times and then a few more,
Then I researched the 6L80 VS the 2004R (Which is in my other car) and this is what I came up with.
Caprice 6L80 +2.92 VS GN 200-4R +3.42

1 4.027 ------------ 2.74
2 2.364 ............ 1.57
3 1.532 ............ 1.
4 1.152 ............ .67
5 0.852
6 0.0667

Rear 2.92 ........... 3.42
Below chart is based on a 27.65 Tire

So why do you NEED a 3.27 or 3.45, What am I missing?
FYI a few of my friends are moving from the 3.42 to 3.23 and then 3.08s
Attachments
final drive Caprice VS GN.png
final drive Caprice VS GN.png (38.89 KiB) Viewed 7566 times
2014 Caprice V8
Elgin E-1840 P, LS9 Head gasket, LS7 Lifters, PAC-1218 springs, Trunion upgrade, Single roller timing set, Melling oil pump, ZL1 torque converter, Camaro Trans pan and filter.
1986 GN
212/212 Roller cam, 1.65 HR Rockers, 60-1 turbo, XFI 2.05, E85, Ebay Front mount IC, Husek Built TH200-4R trans, 3.42 gears 3800# .
1968 Chevelle
LQ4, 4L80, 12 bolt w/3.42 gears
User avatar
kevink
Posts: 480
Joined: Sun Aug 09, 2015 12:55 pm

Re: Anyone have b4/aftr 3.27 ET

Post by kevink »

Turbopowered68 wrote: Fri Dec 04, 2020 7:40 am So why do you NEED a 3.27 or 3.45, What am I missing?
Trapping at a higher RPM is one reason.
2011 9C3: 11.48 @118.
Numbah1
Posts: 75
Joined: Sun Jan 27, 2019 9:45 pm

Re: Anyone have b4/aftr 3.27 ET

Post by Numbah1 »

My cars on a 1 inch smaller tire and is shifting like 150ish feet before the line. Tried low and instead of blowing up it shifted. I trap at 105 and in 4th thats like 4400 rpm lol stock dyno sheets look flat from 4.2-5k anyway. I primarily race 1/8, im at 4500 at the end there too so it just sucks.

Guess ill add my best is a 13.42 with 0 DA, is full exhaust, full intake minus a ported TB, and no tune yet. Im holding off on the tune for now as it would put me way ahead of my group of frienemies
Numbah1
Posts: 75
Joined: Sun Jan 27, 2019 9:45 pm

Re: Anyone have b4/aftr 3.27 ET

Post by Numbah1 »

Got it!
Last yr i ran;
• 2.045 60', 5.735 330', 8.748 1/8 @ 82.04 & 13.46 @ 104.6 with ~900 DA.
I went 2.5 exhaust from 2.25 x pipe and 2.0 oem pipes (still had cats so it didnt change it) and ran;
• 2.062 60', 5.71 330', 8.715 1/8 @ 82.3 & 13.44 1/4 @ 104.7 with ~200 DA
• 2.07 60', 5.71 330', 8.71 1/8 @ 82.45 & 13.42 1/4 @ 104.7 with ~250 DA

Then a last weekend w/ the 3.27;
•1.994 60ft, 5.620 330', 8.577 1/8 @ 83.80 & 13.26 1/4 @ 105
•2.000 60', 5.65 330', 8.632 1/8 @ 83.25 & 13.33 @ 105
•2.041 60', 5.695 330', 8.677 1/8 @ 83.1 & 13.39 @ 104.5. The DA was 400-550 the entire day. it lowered it ~.15
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