SilverSurfer

Like it reads above. I'd like to hear your best times w/ 2.73s. Please post all mods, race weight w/ driver and what converter you're using. I ran my car last week and got several 12.5s at 113-114 mph. Car dynoed 400 HP SAE to the wheels, with only 15* of timing (3.96* KR mod ). Tea 1.5s, TR 224 114 lsa, LS6 intake, Pacesetters and ORY, Borla, Asp, tuning. Still have the stock converter and 2.73 gears. Race weight w/ driver and 2/3-3/4 tank of gas is about 3675-3700. I'm curious to know how fast those 2.73s can take me and what's the biggest converter that will work with them.

Thanks.

CamaroCain

iTrader: (1)

if you get a converter you will also want to do gears at the same time. I wouldnt go any lower than a 3600 stall and would run at least a 3.42 gear. Run the car with less than 1/2 a tank of gas, and pull any weight out you can easily. What tires are you running on at the track?

SilverSurfer

245/50 r 16 nittos on stock rims, with a lousy 1.96 60'. I know the 60's time are due to the stock converter and 2.73s. I hate to say it, but I love them damn 2.73s, even though they're killing me. LOL I have a 2800 Protorque conv that I bought used and brought it to them to be loosened and checked. We'll see what happens when I put it in.

Thanks for the reply and keep em coming please.

CamaroCain

iTrader: (1)

Nittos? You really need at least some ET Streets or Hoosier QTPs.

Plum Crazy Rob

iTrader: (3)

For 2.73 H/C, I think its just you and me, bud

Mods (headers = Hooker and dual cutouts though) and raceweight are the same as yours. Dropping the raceweight to 3100 and going to a track with -2000 DA will put a 2.73 H/C into the low 11s (not that anyone has tried, but I know my results full weight at the local cow path prove it could easily be done. FYI, for comparison, our fastest local LS1 H/C/gears/full weight has run 11.70). My converter is a Yank ST4000 and shift extension is 5100 RPM. Going to a 4400 converter and raising the shift extension to 5700 would probably drop another tenth at least.

I run thru the end of the quarter in 2nd gear at 6600 RPM.

The disadvantages of the 2.73 gear are well known. You are leaving 2 or 3 tenths, and MPH on the table, all else being equal.

The advantages to me are:
1) Retaining 20+ MPG gas mileage, and not cruising on the highway at nearly 3000 RPM.
2) This gearset allows you to not shell out $3k for a 12-bolt, effectively limiting torque to the axles to acceptable levels, while the ring and pinion are stronger than any deeper ratio 7.5" 10 bolt gear. Limiting the torque also allows for great performance on street tires, while the car is hardly a slug thanks to the converter. Its truly kooky, but something to think about.
3) The look on dyno operators faces when you run their dyno up to ~195 MPH locked in 3rd at 6900 RPM - priceless.
4) Keeping the dreaded WOT 2-3 shift to an absolute minimum.
5) Proof positive that a torque converter is more important than deeper gears.

Have some fun with the 2.73s. They mess with people's minds
BTW, my setup is two years old and was the first set of LS1 heads CHS had done. Going to the latest combos (G5X-3, latest port design, LSX, etc) would be good for another 50-70 RWHP...

gator's 99TA

iTrader: (2)

rob you are nuts. you have this 2.73 gearing racing down. but remember that a 3.23 geared 4L60e has more overall gearing than a 4.10 geared MN6 car. so it isnt like you have horrid gearing overall.

i will agree with et streets, good track, and some 3.73 gears you personally would loose 3 tenths EASILY. you know i am not affraid of gearing.

Plum Crazy Rob

iTrader: (3)

Hi John. I knew you wouldn't miss this. How's the Gators

Yes, it seems like most people forget about the benefits of the 3.06 first gear in a 4L60-E....

QuickSilver

iTrader: (22)

My best with my 2.73's is a 12.17@ 113 with a 1.80 60' Cap laid down 400 at the wheels with the convertor not wanting to stay locked.

The car is a h/s car with NO susp. mods at all. ST-3500 convertor and long tubes.
Not to bad i guess.
Josh

SilverSurfer

I tried the 2nd gear finish, but I bounced off the limiter hard. How do you do it with a stall, and I can't with the stock converter?

SilverSurfer

Hey Gator, what do you run at the track?

Plum Crazy Rob

iTrader: (3)

Hmmm, I don't know the answer to that. There should more slippage, as you indicated, with the Yank than the stocker. What is your limiter set at, actual engine RPM via Autotap and/or LS1edit (ignore the stock tach) ???

Mine's at 6900 RPM, and as I said, I go thru at 6600...sometimes I will hit the limiter JUST AFTER the finish line when I get carried away and don't get out of it soon enough...are you SURE you hit it BEFORE the finish line? You would not be mistaking the finish line for the stripe that most podunk tracks have 66' AFTER the finish line where the OLD style speed traps used to end??? (both tracks here still have this. Sand blasters are expensive, you know... )

PS, I would strongly recommend a 3500-4000 Vig/Yank/TCI for the converter. Other brands are cheaper, but I would question the efficiency and quality.

SilverSurfer

Yup, set to 6600. Happened about 75-100 feet from the finish line.

Protorque is a good converter. Had one on my 87 TR bolt on car. She ran 11.65 at 115 unlocked and 117 locked with a 1.56 60'. 4000 rpm launch ( foot brake and e-brake launch ) with 20 psi of boost at the line. Car weighed 3700, no front sway bar, 28x10 MT slicks on Western 15x8.5 t-type look-alike wheels (real heavy). Big turbo (t63e) , FM intercooler (CAS V1), 3" downpipe, 55 lb injectors and Walbro 340M in-tank pump, Max Effort chip ( set to max fuel position ) and 26 psi of boost w/ C16 in the tank. No tuning and 100,000 mile long block.

CamaroCain

iTrader: (1)

semms like you did your modding backwards or something

gator's 99TA

iTrader: (2)

my car has run a best of 11.59 @ 116.8 (1.51) @ 3590 lbs raceweight. should be a bit faster this coming year.

anyways, enough with the thread hi-jacking. my car has nothing to do with a 2.73 geared car

SilverSurfer

Me?

Well, I wanted to play around with the car and see what I could get out of it with the stock drivetrain and weight. No weight reduction here. I sit and scratch my head when I see people gutting brand new cars. I like to run my cars in street trim at the track. Not trying to set any records, just use the track to gage my performance. I really don't want to dump 2 grand into a rear, 1500 for a tranny and so on. I recently bought a 02 Z28 M6, so the 98 might be going the race car route. We'll see.

Plum Crazy Rob

iTrader: (3)

THAT is totally weird. I've been able to do it on BOTH tracks here, so that kinda rules out some track quirkiness. I hope your tranny is not slipping (slipping at the top of 2nd gear is not usually a problem!). I do now run a set of M&H ET-street type tires that probably grow a bit over the stated 26" dia. I've run 12.03 on Nittos at the same joint with a 1.69 60'.

PS, I have replaced the stock rod bolts (and for that matter, the rings are Speed-Pro of a higher than stock tension, costing me HP at the expense of not having to worry about flutter and oil-burning) in the '98 engine. I wouldn't go 6900 on the stock '98 bolts....

foff667

iTrader: (2)

within the next few weeks my perimeter bolt S2 heads/tsp 231/237 cam will be installed and tuned Im hoping to run 11.8's w/2.73's with my tci 3500 stall and hoosier QTP's out back...anyone think its possible?

SilverSurfer

Before the H/C and headers I would finish the 1/4 in 2nd and hit the limiter as I passed the last 66' MPH light. Was running 108 back then. Maybe it's because you 60' much better than me. That could have something to do with it. You cover 1320 feet alot quicker than I.

Plum Crazy Rob

iTrader: (3)

Absolutely, and more. In fact, I've been waiting for one of you sea-level guys with access to a well-prepared track to try this....

foff667

iTrader: (2)

thanks rob thats what i wanted to hear I'm thinkin I can cut high 1.6's in the 60's and hopefully trap at over 116 so it should get me where i need to go, HOPEFULLY...I kinda put a wager on it hehe.