Need advice for power before boost
Thread Starter
Staging Lane
iTrader: (6)
Joined: Oct 2009
Posts: 54
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From: Hopewell junction, NY
Need advice for power before boost I’ve done my reading and searching and just can’t find an answer to achieving power /acceleration before the turbo kicks in.
95 Camaro
ls1 stock except 224/224 .563. 112 cam
m6 3.42 rear
about 10 lbs of boost -550-600 hp
comes in quick and full around 3k rpm. Maybe less
Huron kit with on3 76 turbo
I felt the car was much more fun to drive from a stop when I had 425 hp head/ cam and 4.10 gears, though now it pulls much much harder , I just am slow from a start. A 2step is not what I’m looking for. I don’t do any track time. Strictly a play car around town. I know some gear would help from a stop but there is a ton of reading on that subject and keeping the 3.42’s. Any other options or ideas ? With the nittto 555’s I bet I couldnt even spin the tires from a stop without really dumping the clutch. Once I’m up and going it’s a lot of fun to drive but I need more from the start.
Any thoughts ?
95 Camaro
ls1 stock except 224/224 .563. 112 cam
m6 3.42 rear
about 10 lbs of boost -550-600 hp
comes in quick and full around 3k rpm. Maybe less
Huron kit with on3 76 turbo
I felt the car was much more fun to drive from a stop when I had 425 hp head/ cam and 4.10 gears, though now it pulls much much harder , I just am slow from a start. A 2step is not what I’m looking for. I don’t do any track time. Strictly a play car around town. I know some gear would help from a stop but there is a ton of reading on that subject and keeping the 3.42’s. Any other options or ideas ? With the nittto 555’s I bet I couldnt even spin the tires from a stop without really dumping the clutch. Once I’m up and going it’s a lot of fun to drive but I need more from the start.
Any thoughts ?
Lots of power down low is a good way to break stock rotating parts.
But, if you have a boost controller, just have boost come in as fast as you can make it while not over shooting the max amount.
But, if you have a boost controller, just have boost come in as fast as you can make it while not over shooting the max amount.
Thread Starter
Staging Lane
iTrader: (6)
Joined: Oct 2009
Posts: 54
Likes: 1
From: Hopewell junction, NY
.80 cold side
.96 hot side
should be on 3’s basic 76 turbo
Down pipe is 3”
I have a manual boost controller , are you saying a different controller may help ? I just don’t see building boost any quicker than I do already. It’s really the first 50’ or so that I need to improve. After that I’m into boost and good. From a roll, even a slow roll , it’s plenty fine. It’s just from a stop I’m lagging
.96 hot side
should be on 3’s basic 76 turbo
Down pipe is 3”
I have a manual boost controller , are you saying a different controller may help ? I just don’t see building boost any quicker than I do already. It’s really the first 50’ or so that I need to improve. After that I’m into boost and good. From a roll, even a slow roll , it’s plenty fine. It’s just from a stop I’m lagging
The gear change will make a big diff. Put a 4.11 back in it and you'll have a lot more low end out of boost.
The tune up in the area pre-boost can also have a huge impact. You need a tuner that knows what they are doing. You aren't running much boost. You should pretty much have NA timing in it until 5lbs or so. I see tons of tunes with 10-15* of timing in the tune as soon as positive manifold pressure comes in. That will make for a ton of perceived "lag".
Power below 3k is kind of an odd request as well. The only time you should be below 3k is in 1st gear. And the gear ratio in 1st should take car of the "lag". Other wise you shouldn't ever be below 3k and flooring it. You need to down shift if you are before going WOT.
Could also be a boost leak.
And yes, the boost controller could be allowing the WG to slightly open before your desired boost pressure is met. You want no signal to the lower port on the WG until your target boost is reached. You need to verify how your specific controller works.
The tune up in the area pre-boost can also have a huge impact. You need a tuner that knows what they are doing. You aren't running much boost. You should pretty much have NA timing in it until 5lbs or so. I see tons of tunes with 10-15* of timing in the tune as soon as positive manifold pressure comes in. That will make for a ton of perceived "lag".
Power below 3k is kind of an odd request as well. The only time you should be below 3k is in 1st gear. And the gear ratio in 1st should take car of the "lag". Other wise you shouldn't ever be below 3k and flooring it. You need to down shift if you are before going WOT.
Could also be a boost leak.
And yes, the boost controller could be allowing the WG to slightly open before your desired boost pressure is met. You want no signal to the lower port on the WG until your target boost is reached. You need to verify how your specific controller works.
Thread Starter
Staging Lane
iTrader: (6)
Joined: Oct 2009
Posts: 54
Likes: 1
From: Hopewell junction, NY
I have to get the car out and look at the timing. I really don't think I a power issue, the car has plenty of power and I did all the driving and logging for the tuner and saw he pushed the timing as much as he could. the "power" I am looking for under 3,000 rpm is better described as acceleration, and yes its just in 1st gear and starting from a stop. I know the gear change would fix my issue since I've had 4.10 in my NA set up, I just have read so much about staying away from those gears with the turbo. I don't want to be in a situation where I am going through the gears too quickly and not optimizing the load/boost issue that's been discussed on here.
If lag and part throttle is the issue, I wouldn't go to a steeper gear. I just went from 4.10s to a 3.42 and it's so much better. The motor was outrunning the turbo in my instance. Either tighten up the toon or move to a smaller turbo if you don't have plans to grow. If you want part throttle boost and all in by 3k, just shrink the turbo, but at the expense of top end power.
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TECH Fanatic
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Have you checked the code for the tranny. There appears to be two different gear sets for the 95 T-56 according to this chart. The top appears to be close ratio. The second row is wide ratio.
On my stock 95 Z28 with an auto (4l60e) with the wide ratio gear set (1st 3.06 - 2nd 1.63) would blow the tires pretty easy. The wide ratio on the 6 speed is a big swing from first to 2nd and similar to the 4l60e. This might explain why doggy from a dig.
TREMEC
T-56
1st 2nd 3rd 4th 5th 6th Torque
2.97 2.07 1.43 1 0.8 0.62
2.75 1.78 1.3 1 0.74 0.5 450-650
2.66 576-880
On my stock 95 Z28 with an auto (4l60e) with the wide ratio gear set (1st 3.06 - 2nd 1.63) would blow the tires pretty easy. The wide ratio on the 6 speed is a big swing from first to 2nd and similar to the 4l60e. This might explain why doggy from a dig.
TREMEC
T-56
1st 2nd 3rd 4th 5th 6th Torque
2.97 2.07 1.43 1 0.8 0.62
2.75 1.78 1.3 1 0.74 0.5 450-650
2.66 576-880
Last edited by dlandsvZ28; Oct 8, 2021 at 10:02 AM. Reason: edit content
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Verdad Gallardo I have to get the car out and look at the timing. I really don't think I a power issue, the car has plenty of power and I did all the driving and logging for the tuner and saw he pushed the timing as much as he could. the "power" I am looking for under 3,000 rpm is better described as acceleration, and yes its just in 1st gear and starting from a stop. I know the gear change would fix my issue since I've had 4.10 in my NA set up, I just have read so much about staying away from those gears with the turbo. I don't want to be in a situation where I am going through the gears too quickly and not optimizing the load/boost issue that's been discussed on here.
"Staying away" from a more efficient gear with a manual trans is nonsense. Turbo or not. Auto cars can get away with ridiculous tall gearing because they can preload and build boost from a stop. Once boost is built they never let off the throttle. If you want to behave as it did previously. Put the 4.10 back in it and enjoy. You have two OD gears. Should be just fine with 4.10s. Or maybe meet somewhere in the middle. Go with a 3.73 or 3.90. Don't' listen to band wagon BS. You don't need a tall gear for a turbo car. You need the right gear for your combination and intended use.
Thread Starter
Staging Lane
iTrader: (6)
Joined: Oct 2009
Posts: 54
Likes: 1
From: Hopewell junction, NY
My bad, so the trans and motor are both 2002. But I’ll take a look for any codes on the trans.
I do think a 3.73 or 3.89 would be my answer, however I’m now thinking that my cam isn’t helping things. I know “all NA cams make power with boost” however I may be losing cylinder pressure and bleeding boost which may be hurting my low end power. In fact when I had the cam and long tubes in the first set up I noticed a huge loss in bottom end power and fixed that by putting 4.10 in the rear.
The cam is Thunder racing 224/224 .563/.563 112 LSA
Originally I didn’t think it was worth the hassle to change to a turbo cam but I’m second thinking that now
I do think a 3.73 or 3.89 would be my answer, however I’m now thinking that my cam isn’t helping things. I know “all NA cams make power with boost” however I may be losing cylinder pressure and bleeding boost which may be hurting my low end power. In fact when I had the cam and long tubes in the first set up I noticed a huge loss in bottom end power and fixed that by putting 4.10 in the rear.
The cam is Thunder racing 224/224 .563/.563 112 LSA
Originally I didn’t think it was worth the hassle to change to a turbo cam but I’m second thinking that now
If you are super concerned about power below 3k an OEM cam would best suit you. That's generally not an area of concern for any "race" toy. IMHO a gear change is easier than a cam swap. And you wouldn't give up 100hp above 5500 or so you get with your current cam.
That TR224 has very little overlap so your are not bleeding off much if any boost with that cam. My guess is the timing is lazy from part throttle to low boost as mentioned in post #5.
Thread Starter
Staging Lane
iTrader: (6)
Joined: Oct 2009
Posts: 54
Likes: 1
From: Hopewell junction, NY
Thanks for the input, I will have to do some logging and look at the tune before making any changes. It may be a bit before I have a resolution but I will be sure to update this thread to help anyone in the future. Thanks again.