Lsj/tvs engine build #2
09-07-2013, 07:37 PM
#80
I saw the pics on FB on the block mods. Looking good man. Its a shame I couldn't come help with assembly and things like this. Love to learn a little more about our motors.
I for one want to do a small pulley on the TVS. I'm not in it so much for the more hp it brings but the torque it produces lower and how the powerband shifts earlier. Yes you may bring in more wheel spin but if you can have good foot/throttle control and great tires you can definitely use the extra power to your advantage.
I for one want to do a small pulley on the TVS. I'm not in it so much for the more hp it brings but the torque it produces lower and how the powerband shifts earlier. Yes you may bring in more wheel spin but if you can have good foot/throttle control and great tires you can definitely use the extra power to your advantage.
09-07-2013, 09:26 PM
#81
I saw the pics on FB on the block mods. Looking good man. Its a shame I couldn't come help with assembly and things like this. Love to learn a little more about our motors.
I for one want to do a small pulley on the TVS. I'm not in it so much for the more hp it brings but the torque it produces lower and how the powerband shifts earlier. Yes you may bring in more wheel spin but if you can have good foot/throttle control and great tires you can definitely use the extra power to your advantage.
I for one want to do a small pulley on the TVS. I'm not in it so much for the more hp it brings but the torque it produces lower and how the powerband shifts earlier. Yes you may bring in more wheel spin but if you can have good foot/throttle control and great tires you can definitely use the extra power to your advantage.
09-08-2013, 12:45 AM
#84
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FWIW, I run the TVS on a 2.7" with the ATI. I built the motor for what my goals were, as should anyone. John, I know your goals are different, and that's what your built your setup for. To each his own.
09-09-2013, 11:33 AM
#85
Don't do back to back to back pulls with a small pulley and you will be just fine if your cooling system is in working order. Power starts to fall dramatically however if you are doing repeated pulls, and I mean dramatically. Foe me, I spend 99.9% of my time on the street just messing around or doing roll races on the street where there is adequate airflow and cool down time between runs usually, and take 1 trip to the dragstrip every year. I still have a 2.9 pulley in the drawer if I ever decide to make the drive out to Brainerd to BIR to road race. Maybe someday.
Steve, glad you are sticking with it!
Steve, glad you are sticking with it!
09-09-2013, 12:33 PM
#86
I agree to an extent. The low torque is so much greater on the 2.7" than the 3.1 or 2.9. Heat will always be an issue, especially if you are winding out the gears on long pulls. If you only want a peppy city cruiser that has low torque and the occasional windup through the gears, then a small pulley is perfectly fine. If you are a road course lap master then a larger pulley would probably be better.
FWIW, I run the TVS on a 2.7" with the ATI. I built the motor for what my goals were, as should anyone. John, I know your goals are different, and that's what your built your setup for. To each his own.
FWIW, I run the TVS on a 2.7" with the ATI. I built the motor for what my goals were, as should anyone. John, I know your goals are different, and that's what your built your setup for. To each his own.
anyone got those to share?
tx
09-09-2013, 12:59 PM
#87
Peak tq gain was 14 ft/lbs and peak hp gain was 11whp. Both in the mid range. Diminishing returns by redline, and then you can see the slippage around 105mph. Revved to 7600 for these pulls.
09-09-2013, 01:07 PM
#88
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I do, 2.9 to 2.7 within a half hour actually. Back over a year ago on a dyno daynamics, but you still get the idea. Also had some belt slip as you can see, but it wasn't until up top so the mid range was unaffected. Right after the shop got their dyno so we were messing around doing a bunch of pulls. Did 10 pulls on the 2.9 then a couple on the 2.7.
Peak tq gain was 14 ft/lbs and peak hp gain was 11whp. Both in the mid range. Diminishing returns by redline, and then you can see the slippage around 105mph. Revved to 7600 for these pulls.
Peak tq gain was 14 ft/lbs and peak hp gain was 11whp. Both in the mid range. Diminishing returns by redline, and then you can see the slippage around 105mph. Revved to 7600 for these pulls.
09-09-2013, 01:26 PM
#89
Here was how it went. Dialed on the street for 11.5 AFR climbing to 11.8 by redline (ran it leaner then than I do now), pulled on the dyno and did a few dyno calibration pulls, did the first full pull and AFR was low low 10's. Less airflow and more load from it being a dyno dynamics? Not sure. Car made 310whp lol. Started leaning it out and after 11.8 up top I was losing power, so 326whp on the 2.9 was where she sat. IIRC 27.5* up top. Swapped to the 2.7 and added a tiny amount of fuel, was still a tad lean and was at 27* up top and 1* short of the 2.9 run the rest of the pull. Made 326whp peak and saw the minor abrupt fall at 105mph, and thats when we looked through the boost logs and realized the belt was slipping. Added the timing to mimic the 2.9 map and added some fuel to run the same AFR and did the last pull with the same timing and AFR as the best 2.9 run and come up with those results.
I then fixed the belt issue a few days later and never went back because the gain was minimal. I do need to go back now though because after I ran on the Dynojet these guys called me and said I could come dyno for free to get a comparison. We will see what 370whp on a dynojet equates to on this local Dyno Dynamics. I'd like to say it will be a nice comparison for this dyno as well, but so may things have changed on their end since this dyno.
Here is one thing interesting. On the 2.9 I trapped 113.25mph, on the 2.7 identical to how it was in this graph I trapped 116.0. On the same 2.7 with the slip fixed, new injector scaling, and a little more know how, I trapped 119, with nothing else mechanically changed.
I then fixed the belt issue a few days later and never went back because the gain was minimal. I do need to go back now though because after I ran on the Dynojet these guys called me and said I could come dyno for free to get a comparison. We will see what 370whp on a dynojet equates to on this local Dyno Dynamics. I'd like to say it will be a nice comparison for this dyno as well, but so may things have changed on their end since this dyno.
Here is one thing interesting. On the 2.9 I trapped 113.25mph, on the 2.7 identical to how it was in this graph I trapped 116.0. On the same 2.7 with the slip fixed, new injector scaling, and a little more know how, I trapped 119, with nothing else mechanically changed.
09-09-2013, 01:39 PM
#90
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So... there it is. The smaller pulley can equate more power, especially under the curve. More mph in the quarter and winning races. Is it worth it? I think so. I do appreciate the input, Taylor. I still have a 3.1 and a 2.9 in addition to the 2.7 that's on the car. I will keep the others as backup and options but stick to the 2.7 for now.
09-09-2013, 01:43 PM
#91
In my opinion it is worth it as well. But we may have a different mindset than some, and it all depends on what the car is used for and how much safety cushion the user wants. Are the gains drastic? Not by any means. However, they are there and they seem more exaggerated at the track than they do on paper (dyno graph)
09-10-2013, 12:56 AM
#92
Now I like seeing some data and be able to show the differences. I agree on the small pulley as well. Don't keep dong back to back pulls and you won't heat soak it. I had the 2.5 on my Cobalt and never lost to a bigger pulley car because I max out the M62 or made it inefficient. That was even going to a 75k redline.
I look forward to pulling down on mine. I now have the means to up the fuel system and valve train on the car to hit 8k :-)
I look forward to pulling down on mine. I now have the means to up the fuel system and valve train on the car to hit 8k :-)
09-12-2013, 10:55 AM
#94
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