My buddy says....."Not possible!"
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My buddy says....."Not possible!" Okay, let's hear what you all think....and of course I will try to prove everyone wrong. (With some help of course)
My 3870lb Chevelle with Stock 5.3, Twin PTE62/62's, 20lbs of boost, E85, and water/meth injection, TH400, 3.90's. 28" tall tire, PTC 3400 Convertor ran a best of 118mph, 1.50 60ft, and 6.31.
Now, I have another 5.3 but have twin On3 70mm turbo's with a .68 AR. My PTE62's had a .58 AR. I am also going to change the rear gear to 3.08 or 3.42, same cam, same fuel and some better tuning I think I can get this car in the high 5's at the same boost. He says "No-Way" He says turbos are way too big and my gears will be way too tall. I also will be running a 30" tall tire (315/60 vs a 275/60....
So, I have to keep the same cam, use a 5.3, these turbo's, no convertor tweaking, and one of the above mentioned gears. What do you all think? And Why? I know Skinnies and Denmah have said no in another thread but why?
I think if I advance my cam, use the 3.08's or 3.42's, race on E85 with the more water and less methanol injection and a little more agressive tune that I can reach it. Let's hear your opinions.
My 3870lb Chevelle with Stock 5.3, Twin PTE62/62's, 20lbs of boost, E85, and water/meth injection, TH400, 3.90's. 28" tall tire, PTC 3400 Convertor ran a best of 118mph, 1.50 60ft, and 6.31.
Now, I have another 5.3 but have twin On3 70mm turbo's with a .68 AR. My PTE62's had a .58 AR. I am also going to change the rear gear to 3.08 or 3.42, same cam, same fuel and some better tuning I think I can get this car in the high 5's at the same boost. He says "No-Way" He says turbos are way too big and my gears will be way too tall. I also will be running a 30" tall tire (315/60 vs a 275/60....
So, I have to keep the same cam, use a 5.3, these turbo's, no convertor tweaking, and one of the above mentioned gears. What do you all think? And Why? I know Skinnies and Denmah have said no in another thread but why?
I think if I advance my cam, use the 3.08's or 3.42's, race on E85 with the more water and less methanol injection and a little more agressive tune that I can reach it. Let's hear your opinions.
here is the thing, your buddy is right, but wrong at the same time.
the new turbos are bigger so will spool slower. he is right there. but if you are leaving of a tbrake, that combo will run the same time as it did before because you are in a similar efficiency area of both turbo maps.
where he is wrong is, you already ran 118mph. in a well setup combo, that would be a 5 second pass. the area of opportunity for you will definitely be in the 60ft. it needs to be in the low 1.30s
to get there, you have to leave on more boost, and a higher rpm. what boost and rpms are you leaving on right now?
again, this is what i like to use to see a combos potential
http://www.rehermorrison.com/PdfFile...eriesHP_ET.pdf
the new turbos are bigger so will spool slower. he is right there. but if you are leaving of a tbrake, that combo will run the same time as it did before because you are in a similar efficiency area of both turbo maps.
where he is wrong is, you already ran 118mph. in a well setup combo, that would be a 5 second pass. the area of opportunity for you will definitely be in the 60ft. it needs to be in the low 1.30s
to get there, you have to leave on more boost, and a higher rpm. what boost and rpms are you leaving on right now?
again, this is what i like to use to see a combos potential
http://www.rehermorrison.com/PdfFile...eriesHP_ET.pdf
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Keep in mind, I had only tuned the car a couple of times. It was still a very basic and conservative tune. Running very fat and very, very, low timing. So I don't think the other set up was ever even closed to maxed, I just made the mistake of trying from 20lbs-23lbs of boost at the track between passes. Got impatient!
I am going to try to use more timing and less boost now.....
I am going to try to use more timing and less boost now.....
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Super fat and no timing..... good way of burning the exhaust valves right outta the motor.
28 degrees outta boost. 16 degrees at full boost. Start at 12-15 psi. Target .74-.75 lambda. Wait till 5-6 psi to pull any timing at all.
READ THE PLUGS. Do wot shut downs and pull em. Get the fuel right...then walk the timing in while watching the fuel. Your target air fuel could get as lean as .78... as rich as .72. Mph will tell you whats best. 18-20 degrees shouldnt be out of the realm possibility for you.
Read the plugs. Read the plugs. Read the plugs. Watch the mph. Listen to what the motor tells you. Shes just like a woman.... she will make her wants and needs known....if you can understand how shes gonna tell ya.
28 degrees outta boost. 16 degrees at full boost. Start at 12-15 psi. Target .74-.75 lambda. Wait till 5-6 psi to pull any timing at all.
READ THE PLUGS. Do wot shut downs and pull em. Get the fuel right...then walk the timing in while watching the fuel. Your target air fuel could get as lean as .78... as rich as .72. Mph will tell you whats best. 18-20 degrees shouldnt be out of the realm possibility for you.
Read the plugs. Read the plugs. Read the plugs. Watch the mph. Listen to what the motor tells you. Shes just like a woman.... she will make her wants and needs known....if you can understand how shes gonna tell ya.
Last edited by LilJohn; Nov 8, 2012 at 10:32 AM.
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Super fat and no timing..... good way of burning the exhaust valves right outta the motor.
28 degrees outta boost. 16 degrees at full boost. Start at 12-15 psi. Target .74-.75 lambda. Wait till 5-6 psi to pull any timing at all.
READ THE PLUGS. Do wot shut downs and pull em. Get the fuel right...then walk the timing in while watching the fuel. Your target air fuel could get as lean as .78... as rich as .72. Mph will tell you whats best. 18-20 degrees shouldnt be out of the realm possibility for you.
Read the plugs. Read the plugs. Read the plugs. Watch the mph. Listen to what the motor tells you. Shes just like a woman.... she will make her wants and needs known....if you can understand how shes gonna tell ya.
28 degrees outta boost. 16 degrees at full boost. Start at 12-15 psi. Target .74-.75 lambda. Wait till 5-6 psi to pull any timing at all.
READ THE PLUGS. Do wot shut downs and pull em. Get the fuel right...then walk the timing in while watching the fuel. Your target air fuel could get as lean as .78... as rich as .72. Mph will tell you whats best. 18-20 degrees shouldnt be out of the realm possibility for you.
Read the plugs. Read the plugs. Read the plugs. Watch the mph. Listen to what the motor tells you. Shes just like a woman.... she will make her wants and needs known....if you can understand how shes gonna tell ya.
I have the engine in the garage now. What is interesting is the #3, 4 cylinders are missing the pistons and the rods. All the other pistons and rods looked fine. Even the rods are still connnected to the crank in 3 & 4 by the arp rod bolts but the rods had "twisted" off.
I plan to do as you an 71 chevy had mentioned and focus more on the timing this time and use less boost instead of less timing and more boost.
Super fat and no timing..... good way of burning the exhaust valves right outta the motor.
28 degrees outta boost. 16 degrees at full boost. Start at 12-15 psi. Target .74-.75 lambda. Wait till 5-6 psi to pull any timing at all.
READ THE PLUGS. Do wot shut downs and pull em. Get the fuel right...then walk the timing in while watching the fuel. Your target air fuel could get as lean as .78... as rich as .72. Mph will tell you whats best. 18-20 degrees shouldnt be out of the realm possibility for you.
Read the plugs. Read the plugs. Read the plugs. Watch the mph. Listen to what the motor tells you. Shes just like a woman.... she will make her wants and needs known....if you can understand how shes gonna tell ya.
28 degrees outta boost. 16 degrees at full boost. Start at 12-15 psi. Target .74-.75 lambda. Wait till 5-6 psi to pull any timing at all.
READ THE PLUGS. Do wot shut downs and pull em. Get the fuel right...then walk the timing in while watching the fuel. Your target air fuel could get as lean as .78... as rich as .72. Mph will tell you whats best. 18-20 degrees shouldnt be out of the realm possibility for you.
Read the plugs. Read the plugs. Read the plugs. Watch the mph. Listen to what the motor tells you. Shes just like a woman.... she will make her wants and needs known....if you can understand how shes gonna tell ya.
I still think the 62's was a better combo. As far as pulling gear I don't think it will hurt you IF you can control power and make it work.
I think switching to lower gears, thus reducing the mechanical advantage, will help improve your times... thats provided everything else is set up correctly. Will allow you to leave on a little more boost/power without overpower the tires (as easily)
Think I would do the 3.42 gear and see how that goes. I think if you get the tune right on the trans brake you should be able to get that 5.3 to spool those 70s. Those 70mm on3 units after all DO have a kinda small turbine wheel. We have one almost finished up on a 5.3 with twin on3 70s. Depending on how it acts we are going to some BW units later, but figured we would get the set up started on the much cheaper on3 units (1/2 the cost on the turbos). Keep it lean on the 2 step and it should come up on boost.
And like 71 chevy said, please get a 3bar! It is not expensive.
And like 71 chevy said, please get a 3bar! It is not expensive.