What 1/4 mile time should i expect?

redauxr8 · 13-09-2010, 02:18 PM

Hi,

My AU XR8 is getting some upgrades, can anyone giv me an estimate of the 1/4 mile times i should be getting with my setup?

Mods are:
Rebuilt engine to handle boost. Not to sure what the specs are. Its basically forged rings etc, still a 302. New trickflow heads and manifold, comp cam.
N/A form made 260rwhp.

Rebuilt auto with 3000 hi stall

Diff rebuilt with 3.9 ratio

Centrifugal supercharger, not yet put on. Tuner expects to make around 400-450rwhp.

Full exhaust system: twin 2.5, pacemaker 4-1s

Cheers

blownv8au · 13-09-2010, 02:30 PM

not sure on your quarter times but with 400 plus rwhp your block will be more than likely on a borrowed time.

The Monty · 13-09-2010, 02:50 PM

Aspirated youd have to think mid to low 13's.
With the supercharger, probably the same as you wouldnt be able to launch it, youd have to baby it off the line, and back right off on gearchanges. Butyoud see more mph with the s/c.
With semi's, a good tailshaft and a really good suspension set up, and a really tough gearbox and axles, it would have to dip into the 12's.

**SSD-85** · 13-09-2010, 03:23 PM

Rule of thumb for factory 302 windsor roller blocks is a 450 flywheel HP limit. Anything beyond that is taking a major risk for engine destruction.

Mr Hardware · 13-09-2010, 03:48 PM

i have always thought about taking my tired old falc out onto the track for a 400m pass

but i'd probably get a 'sunscreen time':

30+

**Whoosha** · 13-09-2010, 03:55 PM

NA with mods are getting mid 13s so boosted you would hope for low to mid 12s not stroking it was probably a good idea

Cam · 13-09-2010, 05:17 PM

What tyres????

You could run a 14 on street tyres or an 12 on semis....

Also what does the "rebuild gearbox" entail? 300rwkw is a lot to push through a standard auto... And then there's the worries of the block..

I would be trying to limit my rwhp to no more then 400, sounds like your pouring some serious money into this thing, I would hate to see it go bang.... Did you consider an aftermarket block? (although you haven't really said whether its a standard block)

Windsor220 · 13-09-2010, 08:43 PM

So it has 260 rwhp now after the NA mods? Thats exactly what mine has and its stock apart from tune. Probably due to the lower compression for boost.
I done a 14.3. It should get a high 13 with a stall and practice.

With the blower I would be looking at a 12 second pass. Im fitting one soon so it will be interesting to see what you get.

redauxr8 · 13-09-2010, 11:09 PM

Sorry i should have mentioned more about the engine.... I am using an aftermarket sportsman block.... The reason for 260rwhp N/A is lower compression and running on 95 octane.

Also, gearbox is a full "performance" rebuild with the best quality parts i have been told.

sleeper393 · 14-09-2010, 12:17 AM

mate with the dart sportsman block not a worry , im betting with proper setup, lose some weight , as per spare tyre out, remove back bottom portion of rear seat , etc etc , and a custom tune with the s/c setup easy low 12 , high 11 with some sticky rears.

Cam · 14-09-2010, 07:25 AM

Great to see your not using the stock block, really will pay off in the long run.. Kudos to you!

Agreed with sleeper393, wack some decent rubber on it and it should see the thing dip into the 11's with some practice...

blownv8au · 14-09-2010, 12:01 PM

redauxr8 great way to start with a aftermarket block they are a good investment something you won't have to worry about as the power levels go up.
I think the main problem you'll have is getting the power to the ground and weight, does your xr8 have irs if so thats a fair bit of weight and they don't seem to put the power to the ground very well for straight line racing, if its not then with sticky rubber and well set up suspension should see some good times.
Btw what type of supercharger did you end up going for?

redauxr8 · 14-09-2010, 12:18 PM

Quote:

Originally Posted by blownv8au

redauxr8 great way to start with a aftermarket block they are a good investment something you won't have to worry about as the power levels go up.
I think the main problem you'll have is getting the power to the ground and weight, does your xr8 have irs if so thats a fair bit of weight and they don't seem to put the power to the ground very well for straight line racing, if its not then with sticky rubber and well set up suspension should see some good times.
Btw what type of supercharger did you end up going for?

Yeh the AU has IRS. Launching the car is gonna be the biggest problem with 3.9 ratio and 3000 hi stall

Im going to see how fast I can get on street tyres and weight, as this is my daily driven car! But ill probably take some weight off and run slicks eventually.

I haven't actually decided on a blower yet. I'm either going to put a vortech or try the raptor out. Im only aiming for 400-450rwhp (at this stage). I am very tempted to put a Kenne Belle on.... I'll have to start a build thread when i get back from work.

sleeper393 · 14-09-2010, 01:11 PM

http://img442.imageshack.us/img442/6315/kennebell.mp4
KENNE BELL SETUP , GOTTA LOVE IT
i'd go the bell setup if you have the $$$$ , positive displacement whipple on the street will blitz. JMO

Stattic · 14-09-2010, 02:20 PM

Looking forward to this car!

**Stav** · 18-09-2010, 04:30 PM

With 450 rwhp you will run 11 seconds to 12 seconds 1/4 mile

ayeyew · 22-09-2010, 07:08 PM

Definately 12.45