Is my car capable of running 12.999 on street tyres?

[Solone]

Hi

I have a VT2 Berlina LS1 Auto. Mods are...

try y extractors 1/3/4 inch with 2.5 inch collectors, 2.5 inch high flow cats, 2.5 inch twin exhaust system, all xforce

OTR CAI made of fibreglass

MAFLESS tune revs to about 6450rpm.

Transmission cooler PWR

New plugs and leads, car runs beautifully.

Is this car capable of a 12.999 (or better) quarter mile on street tyres?

[5.7heaven]

with a decent set of diff gears, yes

[Solone]

with a decent set of diff gears, yes

So your saying no with stock diff gears?

[white lie]

Exhaust, intake and tune... I'd imagine a mid 13 but only 1 way to find out

Put 2-3k in to it with a decent converter and gears and you'll be near a flat 12 with a good setup

[whitels1ss]

So your saying no with stock diff gears?
I reckon it is "possible" but I think from memory most VT Berlinas only had an open wheel,
non limited slip diff so I reckon you will really have your work cut out.;)

[Solone]

I reckon it is "possible" but I think from memory most VT Berlinas only had an open wheel,
non limited slip diff so I reckon you will really have your work cut out.;)

My car has LSD :)

So do I have a 12 on the cards?

[Peter B - CV8]

I don't think it will crack into the 12's. Mid 13's certainly - maybe even low 13's if you have a dream hook up.

[whitels1ss]

My car has LSD :)

So do I have a 12 on the cards?

It is possible in theory with the right tune, tyres and driver on the right day.
You might get there and then again, you might not?

[whitels1ss]

Salone, 12's has been done by a few people with stock diff gears and no stallie, here is a good example of a build and mod. thread,
Post number 38 is where this guy first dipped into the 12's. (in a Maloo ute)
The whole thread might be an interesting read

http://www.ls1.com.au/forum/showthread.php?72863-TAKEITEZ-dwaynE-s-HSV-VY-II-Maloo-Ute/page3&highlight=chipmaster

[sportwagon]

Theres one easy way to find out take it to the track its all just guessing up till then.

[duke5700]

Not with the mods you have unless its a freak or you get freak atmospheric conditions.

Mid to low 13's is more realistic. Your MPH will give you a good indication of the power you have. Somewhere near 110mph would get you close.

[white lie]

Dwayne's Maloo is a great example of what can be achieved with the right mods but IMO is still a rare case. He has a great understanding of what works and what doesn't, wasn't afraid to try new ideas and of course can peddle a car very well. I'm not saying it can't be done, just don't expect it to come easy... especially if you want that time consistently!

[5.7heaven]

3.7s or 3.9s and as they say, you're in low-mid 12s

[whitels1ss]

Dwayne's Maloo is a great example of what can be achieved with the right mods but IMO is still a rare case. He has a great understanding of what works and what doesn't, wasn't afraid to try new ideas and of course can peddle a car very well. I'm not saying it can't be done, just don't expect it to come easy... especially if you want that time consistently!
I agree with you buddy, but the OP asked if it was "possible" ?
I know not many have been able to do it and many have tried and failed but it has been done before.
As others have said a set of diff gears and perhaps a stallie and it is much easier.
Also I reckon if the OP still has the VTII LS1 intake manifold and injectors instead of upgrading to the later
(VX onwards) LS6 intake manifold and injectors his chances would be even slimmer

[fishman88]

ive done a best of 13.1 @ 108mph with hsv vy II headers/ ballistic cats/ Vz hsv catback/ vcm otr and 3.46 diff im pretty close just need to get that perfect hookup off the line and less wheelspin on the 1-2 gearchange. This is on my VX SS auto 184000km on it too. And definitely change the intake manifold to the VX onwards as it mite be holding u back. U ran urs down wsid yet??

[QldKev]

Can we put bets on his run

QldKev 13.3

Solone, it does mean we need a timeslip at some stage to see who wins the time guess :lol:

[VXSS346]

Yep, low 13's, I've done similar too on stock wheels/tyres.

12's has been achieved before by just a handful of people, but I highly doubt anyone has consistently done it on every outing.

Try it out and have fun. :burnout:

[Mitchg]

On street tyres, ill say 13.5@106mph. 2.1 60ft aswell. Your 60ft is gonna be whats stopping you.

[Solone]

On street tyres, ill say 13.5@106mph. 2.1 60ft aswell. Your 60ft is gonna be whats stopping you.

Thanks for the replies, will run it very early in the new year. Hopefully get nice temps.

[Solone]

Alright guys place your bets on my times... Will post my best time slip of the night.

I'm running it tonight at wsid.

To reiterate car is a vt2 ls1 auto, try y headers, high flow cats 2.5inch and twin 2.5 inch system. Running a OTRCAI made of fibreglass and maffless tune. Car has 15 inch wheels with 225/60 series Yokohama all round. No spare or jack and any loose items removed from car. Ls1 has new plugs and coils and 100,000km. Transmission has a pwr cooler on it. Rear tyres are 25psi and front tyres 35psi.

What is best way to launch this car?

I'm going to start with no stall and just mash the pedal, then with each run I'll lift the stall to about 800rpm, then 1000rpm, then 1200 etc etc. on the street I practised a few launches and any more than about 1000rpm just explodes into wheelspin and this was right after stepping off freeway so tyres would have been hot. I will be happy with a 13.5 for the night any quicker and I'll be wrapped!!! Temperature is expected to be high 20s.

So please place your bets for my time and mph and give me any tips at achieving best possible time.

[whitels1ss]

Best of luck buddy.
I will say 13.4 @ 104mph :cheers:

[white lie]

LS1 or LS6 manifold? Burnout or driving around the water? Filter in or out? Have you raced before?

Sorry for 20 questions but there's plenty of variables.
I''ll think between 13.3 and 13.5 is a pretty safe ballpark. Might surprise a few if it gets a dream run but I wouldn't think so.

[Solone]

LS1 or LS6 manifold? Burnout or driving around the water? Filter in or out? Have you raced before?

Sorry for 20 questions but there's plenty of variables.
I''ll think between 13.3 and 13.5 is a pretty safe ballpark. Might surprise a few if it gets a dream run but I wouldn't think so.

Ls1 manifold (unless previous owner changed but I doubt it), do small burnout, filter in, yes ive raced before but not in this car.

Im going for a 13.3 @ 105mph

[SSer]

13.3 @ 106. Good luck and have fun!

[bush_basha]

13.8, 103mph

[STATIE]

13.8, 103mph

Yep - that would be in the ballpark - 13.6 at the outside.

[GTS_365]

High 20's temp will definitely be a disadvantage. I'm going for a 13.5 @ 104

[Solone]

High 20's temp will definitely be a disadvantage. I'm going for a 13.5 @ 104

Right on the money, best run of night was 13.5 @ 104 and 60ft 2.1.

But it was a very hot night out there, timeslip above said 26 degrees. Other timeslips had 29 degrees on them.

I don't think it's a bad effort considering I had 225 cheesecutters tyres all round so couldn't do much off the line, I weigh a good 112kg myself and had half a tank of fuel. Kept air intake filter on for all runs.

Also the gearbox was playin funny buggers end of second gear, sort of slipping a bit. On the street changes are fine.???

Car didn't feel too quick tonight, it feels quicker on cold nights on the street, felt a bit doughy at the track.

Anyhow 13.5 is best I could do tonight in 6 runs, I had three other runs in the 13.6s, one at 13.8 and a shocker where I had too much wheel spin and used economy mode for a 13.9.

I think with a halfway decent set of tyres, cooler temperature and if the gearbox was more progressive in its shifting a very low 13 is possible

[VXSS346]

Well done :goodjob:

[QldKev]

Good Job :driving:

My bet was on 13.3, which on a cooler night I think you could do even better!

[GTS_365]

Nice time mate. On a cool night say around 15 degrees and with a 2.0 60ft, you would be looking at 13.2@106.

[Solone]

What sort of power is my time suggest? 220-230rwkw?

[SSer]

Without an accurate idea of weight of the car including you in it its too hard to calculate from mph. ~235rwkw probably isnt far from the mark for a full weight VT2 Berlina at 104mph.

[Solone]

Update, my tune wasn't right during those runs. It was hitting the limiter before it changed up on the 1-2change and also on the 2-3 change. It was in the tune as one of my runs was done in economy mode and it changed up fine (despite the less line pressure in economy mode)

Made the following changes to car ahead of next time

1. Retuned Saturday with following changes, pause setting in tune changed to zero instead of 0.8 second, rev limiter slightly increased and change up point slightly decreased (6450rpm). Original tune had only 100rpm to play with between change up point and cutout. This buffer now increased and car drives great, progressive changes and launches forward into the next gear with nice big chirp of the tyres.

2. Did the throttle body bump stop mod. Throttle body now opens up fully, stock it didn't open fully despite hitting the bump stop. Hoping for a few extra horsepower here??? Just grinder back the bump stop, now butterfly perfectly opens.

3. Moved air condition condenser back to lean on radiator giving the OTRCAI more space to draw air from, at track condenser was in stock position and OTRCAI was breathing through a straw with that tiny passage. Effectively doubled it's passage to draw air

I'm hoping these changes above are worth a few 10ths, I know the gearbox/tune was holding car up before stopping momentum and the throttle body mod and air condenser should give a few horsepower back.

Might even run no filter at track next time see if it's worth something.

[white lie]

I think pulling the filter will give a tenth at least. I consistently gained 2 tenths with my cam only combo. But overall it should be good for a slight gain, hopefully it's a bit cooler for you too

[mnroo]

I'm a newby here but not on other forums. I have a VT 2 Berlina that almost mirrors yours. It has a full Difilipo 2.5 inch system, OTRCAI and a MAFLESS tune otherwise it's stock. The kick in the pants from a standing start is the same as the 12 second HQ in my back shed. Now although I only wanted a clean, fast street car I'll have to try it at Sydney Dragway! It was only finished a week ago so I've hardly driven it. With new sticky tyres which bogged it down on the dyno it recorded 215kw at the tyres with my mechanic saying it had another 10kw in it. Not bad for a motor which put out 156kw from the factory! With a standard fuel system, electrics, gears etc etc I'm predicting mid 13s for mine but if it does crack a 12 I'll have a bloody big smile on my face!

[Solone]

I'm a newby here but not on other forums. I have a VT 2 Berlina that almost mirrors yours. It has a full Difilipo 2.5 inch system, OTRCAI and a MAFLESS tune otherwise it's stock. The kick in the pants from a standing start is the same as the 12 second HQ in my back shed. Now although I only wanted a clean, fast street car I'll have to try it at Sydney Dragway! It was only finished a week ago so I've hardly driven it. With new sticky tyres which bogged it down on the dyno it recorded 215kw at the tyres with my mechanic saying it had another 10kw in it. Not bad for a motor which put out 156kw from the factory! With a standard fuel system, electrics, gears etc etc I'm predicting mid 13s for mine but if it does crack a 12 I'll have a bloody big smile on my face!


My car definitely has more in it. Pretty happy with my 13.5 @104 considering...

1. Run it on bald 225 street tyres on 15 inch rims, couldn't load it up off the line (2.1-2.2 60ft times)
2. Throttle body mod now done
3. Tune fixed so more momentum through the gears
4. Air passage to OTR opened up.
5. Maybe run without filter next time.
6. Was a boiling hot summer night!!!!

My goal remains at 12.9999!!

[TAKEITEZ]

My goal remains at 12.9999!!
I had a VY II Maloo (auto) and managed to squeeze a 12.999 out of that... Only ever did it once!
Tri-Y headers, cats, twin 2.5"... Alloy otr with filters out... Mafless tune...
That was run on 19" street tyres with stock diff gears. It must have been the perfect run on the perfect night as it never went close again in that guise...

It is possible and the changes you've made might help.. Its a game of practice, optimising your 60'er and waiting for perfect weather - air temp, track temp, baro, wind, humidity etc etc etc...

[Solone]

Without an accurate idea of weight of the car including you in it its too hard to calculate from mph. ~235rwkw probably isnt far from the mark for a full weight VT2 Berlina at 104mph.

id be happy with 235rwkw. Thats about 300kw at motor?

[Phillshz]

Yeah pretty close. IIRC 300kw GTS was 230-240RWKW. VY2 285kw was 225-230RWKW. VZ L76/98 260kw was 200-210RWKW. VE L98 270kw gives 210-220RWKW.

Leave filter in,proven to be no restiction. Maybe see steve from oztrack. He knows WSID well and might have a suitable tune to reach your goal. Some bigger/gripper 17" rear wheels/tyres (SS) would help and a cold clear winters night with high barometric pressure (101-102 kpa) is natures helper. Pull spare/jack/tools/boot liner, run 1/4-1/2 tank of juice, drop rear tyre press 20-25psi and raise fronts 40+ psi. 12.9 is a big ask from your combo, might do it but everything must be perfect. 60ft time is the key.
Don`t stall up, just nail it from idle as it lets the convertor flash to a slightly higher stall speed, leave selector in 3 not D.

Cheers Phill

[whitels1ss]

Leave filter in, proven to be no restiction. Cheers Phill

Never heard that before,
in fact I have heard the complete reverse,
I have heard people say that with filter out on a OTR you will improve by around 3/10ths of a second
and 3mph in trap speed quite a number of times.

[white lie]

Always make improvements on back to back runs when I pull the filter. I certainly know when I've left it in by mistake!

[Phillshz]

Here you go, its a good read. http://www.ls1.com.au/forum/showthread.php?153422-Results-of-Pressure-testing-VE-Intake-systems&highlight=magnehelic

[whitels1ss]

Here you go, its a good read. http://www.ls1.com.au/forum/showthread.php?153422-Results-of-Pressure-testing-VE-Intake-systems&highlight=magnehelic
Yeah, I have seen all that stuff before, thanks anyway. :cheers:

It sounds good in theory but many people have taken the filters out of their
otr's in the real world on the drag strip and seen faster runs.

[Solone]

Ill be making another attempt at the 12.999

But I have a few tricks up my sleeve. A Ls6 manifold getting installed saturday, ported throttle body on its way from the states. Also next Monday a set of 3.46 diff gears will be installed. Getting it all retuned to suit on sat as well.

If I get more favourable weather conditions and turn up with something better than my 225 tyres, I think a 12.999 with above mods is on the cards? Ill even take out my OTR filter.

[Angeldust]

lol, just wait till summers over. nice cool cool temps in the evenings

[Solone]

Next few weeks I'll be back. Ls6 manifold/injectors fitted, retuned, throttle body on its way, diff gears on Monday. Then it's war.