408 Boost motor. n/a Results
08-22-2012, 02:02 PM
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408 Boost motor. n/a Results Just got the car off of the dyno and made 463rwhp and around 410rwtq. Not 100% positive on the torque number, but I will get the graph up tonight. What are motors of similar size that are built for boost putting down N/A?
Iron 408 - around 9.8-10:1 compression.
TFS 220 as cast heads with upgraded exhaust valves
Cam is a 255/263 .623/.623 116 lsa
1 3/4" headers into 3" true duals
Fast 90/90
4L80e
9" rear
17x11 chrome wheels with 315/35/17
Intake/exhaust arent optimal for the 408 and the driveline is definitely not dyno queen friendly, but i'm just running the car how it was setup as a 347 until the turbo goes on it next year. Just got it running and have a wedding to pay for in the spring so the turbo should be going on next summer.
Iron 408 - around 9.8-10:1 compression.
TFS 220 as cast heads with upgraded exhaust valves
Cam is a 255/263 .623/.623 116 lsa
1 3/4" headers into 3" true duals
Fast 90/90
4L80e
9" rear
17x11 chrome wheels with 315/35/17
Intake/exhaust arent optimal for the 408 and the driveline is definitely not dyno queen friendly, but i'm just running the car how it was setup as a 347 until the turbo goes on it next year. Just got it running and have a wedding to pay for in the spring so the turbo should be going on next summer.
Last edited by Jefro6996; 08-22-2012 at 07:06 PM.
08-22-2012, 05:46 PM
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I know E allows you to run much higher timing than normal with a forced induction setup - does it also allow the higher static compression? I was thinking that was pretty high for a 91mm turbo, unless E85 takes care of that.
08-22-2012, 06:58 PM
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Here's a shot of the graph. Ended up at 409 rwtq. Was hoping it would be a little higher, but I'm thinking the cam and lower compression are to blame. The car is running on 93 octane now and I do plan on running E85 when the turbo goes on. The E85 does allow you to run a little higher compression and also helps with knock, which is why i chose a compression around 10:1. Also because this is a street car and i didn't want it to feel too lazy out of boost. The size of the cam also helps out since it lowers the DCR. My tuner thinks I would even be fine running 93 octane with the turbo. I'm not 100% sure if I'll keep the cam with the turbo setup., but it doesn't have a real choppy idle that i like.
Last edited by Jefro6996; 08-22-2012 at 07:08 PM.
08-23-2012, 01:37 PM
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Change the cam...... Gain power everywhere(unless thats a solid roller).. 
Still pretty good numbers for the drivetrain, low compression and horrible cam choice...
Still pretty good numbers for the drivetrain, low compression and horrible cam choice...
08-23-2012, 02:08 PM
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Here's a shot of the graph. Ended up at 409 rwtq. Was hoping it would be a little higher, but I'm thinking the cam and lower compression are to blame. The car is running on 93 octane now and I do plan on running E85 when the turbo goes on. The E85 does allow you to run a little higher compression and also helps with knock, which is why i chose a compression around 10:1. Also because this is a street car and i didn't want it to feel too lazy out of boost. The size of the cam also helps out since it lowers the DCR. My tuner thinks I would even be fine running 93 octane with the turbo. I'm not 100% sure if I'll keep the cam with the turbo setup., but it doesn't have a real choppy idle that i like.
Sounds like it will be a nice setup and heck, the numbers N/A are plenty for most things running around.
08-23-2012, 04:43 PM
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Yeah, I let the engine builder spec the cam. We discussed something around 238/244 and i didn't get the specs on the cam until I was picking up the long block and it was fully assembled. He assured me it is the same cam he runs in all his Turbo motors. I'll most likely switch it out before the Turbo(s) go on next year.
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10-09-2012, 09:04 AM
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Got my buildsheet for my motor and looks like the final compression ended up being 9.17:1, which makes me feel better about the N/A numbers, but not happy since I requested a compression around 9.8:1 to 10:1 since it will be a street car running E85.
10-09-2012, 10:48 PM
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I would prefer that 9.1 over a 10.0 for a boost application, e85 or not.
Cam looks big however that curve looks pretty good. Not bad for what it is. Fuel curve needs a some adjustment.
Cam looks big however that curve looks pretty good. Not bad for what it is. Fuel curve needs a some adjustment.
10-10-2012, 09:05 AM
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I opted for a compression closer to 10:1 since this is a street car that I might take to the track once or twice a year. I didn't want the car to be lazy out of boost since all of the driving will be around town. Not worried about the added compression with E85 and still havent 100% made up my mind if I'm going to run E85 or a race fuel. I've got a few local stations that sell race fuel for a good price and it almost works out the same as E85. E85 isnt that cheap where I live and with the extra 25-30% fuel comsumption i'll experience on the corn it might even end up costing the same as race fuel.
Not dropping any names on the builder. I'm waiting on a response as to why the compression ended up lower than I asked for. He wanted to double check his notes to make sure he had everything correct on the build sheet.
Not dropping any names on the builder. I'm waiting on a response as to why the compression ended up lower than I asked for. He wanted to double check his notes to make sure he had everything correct on the build sheet.
10-13-2012, 09:35 AM
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while it may not be optimum for your car without havung the turbo, i think it's a good set-up for when you do get the turbo. Kinda pointless to have to sacrifice peace of mind having such a high compression for the n/a driving when it can be set up with safe compression and able to handle the boost safely when you start boosting it. i would expect more than 40x from that motor and heads though either way. did he go safe with the timing as well?
10-15-2012, 01:46 PM
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while it may not be optimum for your car without havung the turbo, i think it's a good set-up for when you do get the turbo. Kinda pointless to have to sacrifice peace of mind having such a high compression for the n/a driving when it can be set up with safe compression and able to handle the boost safely when you start boosting it. i would expect more than 40x from that motor and heads though either way. did he go safe with the timing as well?
07-05-2013, 01:39 PM
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lol, that's a good problem to have considering...
So what's the deal? How has this build panned out? I see you have a nice group of turbos there.
My measurements come out to about 9.3:1 CR but it is not official. It ran like an absolute pig, but I have all sorts of boost leaks and it isn't fully tuned. So I decided to redo the whole build and take it slow. I am wondering if the n/a baseline is significant at all in determining the state of the motor?
So what's the deal? How has this build panned out? I see you have a nice group of turbos there.
My measurements come out to about 9.3:1 CR but it is not official. It ran like an absolute pig, but I have all sorts of boost leaks and it isn't fully tuned. So I decided to redo the whole build and take it slow. I am wondering if the n/a baseline is significant at all in determining the state of the motor?