yenkomike

iTrader: (2)

went up and made a couple runs today still shooting for the 9s on my street tune. the air was a little worse than last time but I'm learning my 275 pro ,s like a good heat up and 16.5 psi. still running 12.5 psi or so

first run sucked as the track had water on it so I lifted.

second run was a 1.50 60'
6.50@108.30
10.08@ 133.8

next was a 1.52 60'
6.49 @ 108.80
10.04@134.5 mph.


I wanted to run again but I noticed my car driping from the rear axle and it looks like the pass spring perch is pulling off the axle and it was dripping gear lube. so I took it home

this week ill pull the axle and weld it up and use 1/2 u bolts and get rid of the t bolts. as right now the welds are all that is holding the axle in the car so some u bolts will add extra safety.

not my 9 but I'm happy its a fun car.

3 window

iTrader: (1)

That thing is rockin Mike. An only on 12.5 psi, no less! You can't tell me youre not tempted to turn it up?! Just make 15 psi your new "street tune."

Bad Apache

Agreed. That car is working! And glad you caught the axle problem before you really tore the car up. Your 9 is waiting for you next time out! The weather is getting better and better!

yenkomike

iTrader: (2)

thanks. the tune really is not the issue its traction. any more power and it will come loose about 100 feet out so I'm just working with what I can and getting the 60' down. I might give it a try later this fall with some slicks and some more boost.

Forcefed86

iTrader: (4)

100lbs of sand in the trunk, 3 more lbs of boost! What's your timing curve look like again? Are you adding timing back in after pk tq?

yenkomike

iTrader: (2)

no I'm at 16.5 * at 175 kpa and 14.1 at 220 kpa straight across. to be honest I'm not really running it to far above pk torque. I shift it around 55-5600 and it stays below that thru the traps.

Nitroused383

iTrader: (10)

Why are you shifting so early is it a stock cam?

yenkomike

iTrader: (2)

no but it is small 206/212 at .050 . I just haven't spent much time on the big end I have ran it up o 5800 or so but it seemed about the same so I have just been easy on it working on the first 330 ' keeping it hooked.

I need good shocks and it will pick up. and I might go caltrac bars and ditch my slapper bars.

Nitroused383

iTrader: (10)

Those PTC converters are meant to couple past 6000 rpm atleast most of the ones I've seen. Just shifting that thing around 6500 will put you in the 9's easy, even with the small cam especially with a s480.

Forcefed86

iTrader: (4)

I was just thinking of an easy way to pick up a little power to hit that 9 without blowing the tires of. Little more timing at higher RPM might do it. Some sort of progressive boost control would be my preference.

Peak torque usually follows the boost curve on these engines. As soon as boost peaks, TQ usually does too. I bet that sucker is at full boost well before 5600? If the plugs look good now, you could probably add a degree or 2 after 5k and see if it picks up.

I get you aren’t going all out and are looking to keep the engine alive… but I really don’t think you are doing yourself any favors keeping the RPM that low. Applying 15lbs at 4k is more stressful than adding 15lbs above 5k. Having some way to progressively add boost at higher RPM will help longevity (and traction).

Zero reason you can’t rev it to 6-6500 IMO. I came from the Buick turbo world where everything was low RPM and used the same approach to the LS stuff initially. Moving my shift point from 5500 to 6700 I picked up 2mph. That was on the 9.5” PTC that couples much better at lower RPM as well.

Good luck

3 window

iTrader: (1)

Don't count out the slapper bars quite yet! Spend the $350 on rear shocks first IMO. We've been low 1.30 sixty foots with my buddy's Nova on slappers and QA1 single adjustable shocks. I've got Viking DA on the rear of my Nova. No hard numbers yet, but a very nice shock for the money.

B18B1LS1

iTrader: (12)

Just to echo the guys above, run a few more rpm. Let the horsepower pull it, no reason to grunt it down the track like a diesel. It will be easier on just about everything, minus the valvetrain of course but you should be fine there.

slowlsx

iTrader: (28)

I think shifting that low is nuts especially for a glide! Putting a ton of stress on the rods shifting that low in sure your rpm drop is under 5k. Potentially go faster and be safer for your engine just taking it to 6200-6400

tblentrprz

Yenko, Do you have dyno graph showing peak torque curve with that cam? As others recommended, shifting so you drop to around peak torque is typically ideal. If you have MBT curve (or general perspective), you could pull a couple degrees of timing around peak torque to reduce peak stress and keep the insides of the motor happy.

Ratical

iTrader: (82)

Very nice. You will see your 9's before long for sure.

I have to agree with the majority on the shift points as well. As long as you have the valve springs to handle it twist that thing up a little. Guys are shifting bone stock LS cars at 6800 with a cam and spring swap. I thought a small cam would be a limiting factor on my car too, but boosted engines seem to be a different way of thinking. I have a baby 226/232 cam in my 6.0 and LOS had me pulling to 7k on the dyno. The graph never dropped off even at 7K!

6500 should be nothing if the springs are strong enough.

yenkomike

iTrader: (2)

thanks . i'll wind her up a little and see if it likes it next time at the track.

as far as peak torque it is most likely 4800 to 5000 as this engine has a very small comp 206/212 cam with comp 1.85 rockers it is still only 528/540 lift and there is no issue with valve springs it has a set of pac double springs on it.