pinhead

99 camaro ls1 a4 2.73 gears

I want to start moding

So far the car has free ram air and smooth bellows and tubular lca's it ran 13.48 @105.4 with a 2.3 sixty ft spinning off the line not sure on d/a but the track is at around 100 ft above sea level
My aim is to run high 11s and still be nice and street able it's not a daily it's a weekend car and I may dabble at a bit of bracket racing probably 2k miles a year

I already have some parts for my build not yet fitted
Speed engineering long tubes &ORY
Ls6 intake
Cam motion 222/230 114lsa (cam was for someone else's build and they changed there mind so got it for next to nothing )
Pac beehives
Ls7 lifters

Anyway the first thing I need is traction so I was going to order some 15x10 race stars from summit and get some m/t drag radials from a supplier over here
I intend to leave the cam out for now and put the long tubes on and intake loose some Weight from the front by removing the aircon (doesn't work anyway)
Now here is the rub
Shipping for a pair of race stars is a lot of$$$ to the UK but if I add some other bits to my order it doesn't change that much I can't afford everything right now but can get a few more bits and was thinking of 3.73 and install kit but then I start to read all the converter first threads

So
1 converter or gears

2 what size tyre would you recommend track prep is poor at my local track

3 will I need a tune for the long tubes and ls6 intake

Thanks
Andy

blackandgold

iTrader: (2)

1. I don't have an Auto so this is based on what I've read, but basically: CONVERTER DO IT NOW!!! that will result in a huge gain at the track.

2. A 26" tire should be great at your power levels

3. Unless you live in Cali, do long tube headers even with shorties you're leaving some serious rwhp on the table.

02_SS_SOM

From my own research, Stall converter. If it were me, I'd get the transmission rebuilt to hold more power and take more abuse while it's out of the car. I'm doing catback next with a mild tune, then having circle d install a stall converter and rebuild my 4l60e. Then it's on to the rear end….then I can start in on engine performance hopefully.

99Brd

3600 yank stall, motive 3.73 gears And a set of Mickey Thompson drag radials.

demonspeed

iTrader: (7)

I'd consider lower control arm relocation brackets to help with your traction -- put the arms in the lowest hole. UMI makes a great set, fwiw.

You'd also want to get a tune after doing the long tubes and LS6 intake. While you could still drive around without a tune, it'll make the most of those mods. I'd also do the 2004 LS6 PCV conversion while doing the intake swap.

GDL

I don't know if you have done this yet but have you had a shop do a full inspection on your car?

I've learned the hard way that you always want solid base to start from.

Besides that..... Higher stall for the win!

pinhead

I have put my order in
Fti srls0086 converter
Pair of 15x10 race stars
Fitting kit for wheels
Shift kit
Trans overhaul kit
I thought I would freshen up the trans while it will be out to fit the converter
I have a mate that does quite a lot for his brothers shop

Just need to find some time to fit my headers and intake now

pinhead

I have got my ls6 intake and speed engineering headers and ory fitted as well as relocation brackets and m/t drag radials on the race stars

Had a tune done by my mate with efi live
Went back to the track this weekend and it ran 13.18 @ 107.95 on a 2.01 60ft weather was a fair bit hotter than last time
The car really bogs off the line now and I need to get the stall in
How much do you think I will gain with the stall

RPM WS6

iTrader: (3)

Gains from a proper stall speed can be anywhere from 0.5 to 1.0 seconds, but of course you need to provide traction.

Definitely do the converter, 3500 stall speed at a minimum (this will work great for a stock engine and will still work well after the cam install.) Once this is in place, a 3.73 gear swap won't do much to improve ET and would only be worth it if you want to "tighten up" throttle feel during street cruising. For an LS1/4L60E combo there is no more than about 0.1-0.15 seconds of ET difference between any two gear ratios in the 2.73 to 3.73 range, assuming all else equal, once stall speed has been optimized.

98CayenneT/A

My times
A4, Lt's, drag radials 555r, 2.73's, stock converter
13.28.....60' 2.01
A4, Lt's, Mt et streets, 3.73's, yank 3600
12.39.....60' 1.71

98CayenneT/A

Imo if you're a 2.73 car go to 3.73's, it's worth a couple tenths. You will not be pulling 1.7x 60's with exhaust, converter and 2.73's

RPM WS6

iTrader: (3)

You may want to do a bit more research then.

Not much ET to be dropped from a 2.73 to 3.73 swap once a 3500+ stall speed is already in place. The gain is much bigger for those who still have a stock stall though.

Traction will be more difficult with the 3.73s, so some people don't see any drop in ET at all when doing this swap once they already have a well-matched stall speed.

About 0.1-0.15 seconds is a best-case gain from this swap with a 3500+ stall already in place. For the stock stall, gains of 0.3 seconds or so would be more common.

You can definitely get into the 1.7x or better 60-foot range with an lid/intake/full exhaust 2.73 car with an optimized stall speed and proper tires. Some have gone even quicker than that with stock internals and 2.73s.

pinhead

Thanks guys
I already have a convertor but not fitted it yet it's an fti srls0086 3600 stall 1.86 str
How much difference would I see from 3.42 -3.73
Only reason I ask is there is an axle from a manual car available locally to me for similar $$ to what gears and install kit would cost with the shipping to the UK

pinhead

Just updating the thread
I have run the stall for a season now and it is great
I achieved a best of12.84 on the stock stall in good autumn air
Since the stall I am running consistently in the 12.5 range with a 12.43 best on 2 separate days
Main problem I was having it was still bogging off the line the best 60ft was 1.84 but 1.90 is more common in was expecting better 60ft from the stall but I guess that's 2.73 gears for you

I have now installed 3.73s but not made it to the track again yet
I still haven't installed the cam but it will most likely get done before the season starts so I won't be able to get true comparison of what the gears gained

RPM WS6

iTrader: (3)

The low 1.86 STR on that converter is holding back your 60-foot some. A harder hitting converter, even of the same general stall speed, would bring that down. 2.73s definitely have the potential for much better 60-foot than that. There isn't much actual ET difference between ratios of 2.73-3.73 behind an LS1/4L60E combo with an optimized stall speed; you might drop an extra 0.10-0.15 seconds or so off your overall quarter mile times for that swap alone.

Just to be clear, there are certainly advantages to the lower STR. But maximum 60-foot potential is not one of them.

pinhead

Do you not think that my situation could gain more from a gear swap than someone with a better optimised stall the vast majority of people on this board run yank and circle d 2.5 str converters they typically see a gain of .1-.15 with gears
Now if you have a stock stall you gain .3-.35 with gears
Would you not think that my less than optimised stall would benefit somewhere in between maybe .2-.25

If I were to do it all again I would definitely get a bigger convertor my direction with the car seems to have changed a bit and I drive it very little other than to and from the track but as it is now I have to stick with this stall shipping and import duty doubles the cost of parts here in the UK
I could do with finding someone stationed over here they can get parts shipped on to Base like shipping in the lower 50

RPM WS6

iTrader: (3)

I don't think you'll see double the ET reduction from that gear swap just because of the lower STR. Probably still limited to 0.15 max, but that's assuming both setups were otherwise ideal. You mentioned having a bog, so if the tire you ran with the 2.73s was more than what your setup needed, you might have been leaving something on the table - whereas the new more aggressive ratio might help make proper use of said tire. In other words, you probably never reached max potential with your old setup if you never found the sweet spot between bog and spin, so you might have some additional gains just from correcting the bog regardless of gear ratio.

pinhead

You cannot allow any spin at my local track unless you have a slick, drag radials just don't recover the prep is very minimal
My mate runs a circle d stall heads and cam car with 3.42 gears his best 60ft is 1.69 but he was axle tramping I am surprised his 10 bolt didn't go out his suspension is a bit too stiff in the front with bilstein shocks and big sway bars

I know with the gears I will have a harder time launching but I am prepared to do whatever suspension work I need to get it to hook

pinhead

Little bit of thinking
My convertor is 1.86 str and it hits gently and has knocked around .5 off the et
A yank ss or similar hard hitting convertor would be 2.5-2.6 str and would have likely gained .7

Assume 300 ft lb of torque at 3600 stall speed

300ft lb x1.86 str x3.08 first gear ratio x2.73 axle ratio =4,540.536 delivered torque

Change convertor
300x2.6x3.08x2.73= 6,558.552

Change axle ratio
300x1.86x3.08x3.73= 6410.5272

Change both convertor and rear ratio
300x2.6x3.08x3.73= 8,960.952

As you can see the small str change makes a big difference
How I am reading my results please correct me if I am way off

First calculation is the bench Mark 0.5 off et
Second calculation would give 0.2-0.3 gain in et

Third calculation is very similar end result to calculation 2 so I would expect the same result in et

Forth calculation woukd probably be too much for a 26 inch tall tyre and result in a car that is very difficult to launch and struggle to show gains in et and the reason everyone on this board states gears only gain like .1 if anything