Forged STOCK compression turbo build??
03-04-2009, 08:58 PM
#21
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If you don't plan on turning the boost up you are fine......but I think most of the built guys on here have shown you that you will turn it up.
to me its still just another added level of safety regardless.
I didn't even mention cams before....if you are reving higher you will generally make more power than someone with same setup but not as high a rev limit (my car made the power at a paltry 6200rpm due to stock cams).
Remember boost is just the amount of pressure in the manifold due to RESTRICTION, yes thats right. it is what the heads/valves are holding back....so its not just as simple as saying a b16 does this so a VQ must be the same.....
I say talk to your tuner and come to a conclusion with them.......afterall if it blows up surely you'll blame them first.
tom
to me its still just another added level of safety regardless.
I didn't even mention cams before....if you are reving higher you will generally make more power than someone with same setup but not as high a rev limit (my car made the power at a paltry 6200rpm due to stock cams).
Remember boost is just the amount of pressure in the manifold due to RESTRICTION, yes thats right. it is what the heads/valves are holding back....so its not just as simple as saying a b16 does this so a VQ must be the same.....
I say talk to your tuner and come to a conclusion with them.......afterall if it blows up surely you'll blame them first.
tom
Like I said we are not talking about high boost here, most 4banger go with very low compression coz they all run 25+psi, I'm talking about 14-16psi so I think the 9:5:1 should be able to handle that. I also run W/M so that is an added protection. I mean is 14-16psi really that high that we should all go 8:0:1? I dont think Jeremy will put crazy timing either on that tune so how come he didnt complain about running 18psi on that motor? If it is to risky then he should've just run 14psi on pump gas and no higher..
03-05-2009, 04:24 AM
#22
I went 8.5:1 for a few reasons.
It has been said many times that the driveability difference between 8.5 and 9.5 is not noticeable.
I made sure to overbuild the motor so I can feel somewhat secure when I beat on the car daily.
I built the motor to handle close to 30lbs max boost, but will likely not run at max boost daily, but its nice to know its available if needed. Also, its always possible that I may go nuts on my car like XKR so I won't need to buy things twice.
Lastly, I wasn't trying to reinvent the wheel when I built, 8.5:1 seems to be the most common ratio for the higher HP builds so that made the decision easier yet. If you kept the compression high and went F/I, you may need to do a complete teardown if you wanted to run higher boost in the future. Why do that when you could build with low compression from the start and still have enough HP to walk most cars on the street.
It has been said many times that the driveability difference between 8.5 and 9.5 is not noticeable.
I made sure to overbuild the motor so I can feel somewhat secure when I beat on the car daily.
I built the motor to handle close to 30lbs max boost, but will likely not run at max boost daily, but its nice to know its available if needed. Also, its always possible that I may go nuts on my car like XKR so I won't need to buy things twice.
Lastly, I wasn't trying to reinvent the wheel when I built, 8.5:1 seems to be the most common ratio for the higher HP builds so that made the decision easier yet. If you kept the compression high and went F/I, you may need to do a complete teardown if you wanted to run higher boost in the future. Why do that when you could build with low compression from the start and still have enough HP to walk most cars on the street.
03-05-2009, 04:24 AM
#23
I run 9:1, good balance IMO
I dont make INSANE power, but the power per psi is top notch on pump. I havent seen over 600whp @ 13psi from another 3.5L here. Also in these cars from everything Ive read, having 8.5:1 wont yield a laggier car over 9:1, remember we are driving 3.5L cars not 1.6L Hondas who lag when out of boost. Even the ST kits are full boost by 4000rpm's easy....
I dont make INSANE power, but the power per psi is top notch on pump. I havent seen over 600whp @ 13psi from another 3.5L here. Also in these cars from everything Ive read, having 8.5:1 wont yield a laggier car over 9:1, remember we are driving 3.5L cars not 1.6L Hondas who lag when out of boost. Even the ST kits are full boost by 4000rpm's easy....
03-05-2009, 05:54 AM
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I run 9:1, good balance IMO
I dont make INSANE power, but the power per psi is top notch on pump. I havent seen over 600whp @ 13psi from another 3.5L here. Also in these cars from everything Ive read, having 8.5:1 wont yield a laggier car over 9:1, remember we are driving 3.5L cars not 1.6L Hondas who lag when out of boost. Even the ST kits are full boost by 4000rpm's easy....
I dont make INSANE power, but the power per psi is top notch on pump. I havent seen over 600whp @ 13psi from another 3.5L here. Also in these cars from everything Ive read, having 8.5:1 wont yield a laggier car over 9:1, remember we are driving 3.5L cars not 1.6L Hondas who lag when out of boost. Even the ST kits are full boost by 4000rpm's easy....
If you don't plan on turning the boost up you are fine......but I think most of the built guys on here have shown you that you will turn it up.
to me its still just another added level of safety regardless.
I didn't even mention cams before....if you are reving higher you will generally make more power than someone with same setup but not as high a rev limit (my car made the power at a paltry 6200rpm due to stock cams).
Remember boost is just the amount of pressure in the manifold due to RESTRICTION, yes thats right. it is what the heads/valves are holding back....so its not just as simple as saying a b16 does this so a VQ must be the same.....
I say talk to your tuner and come to a conclusion with them.......afterall if it blows up surely you'll blame them first.
tom
to me its still just another added level of safety regardless.
I didn't even mention cams before....if you are reving higher you will generally make more power than someone with same setup but not as high a rev limit (my car made the power at a paltry 6200rpm due to stock cams).
Remember boost is just the amount of pressure in the manifold due to RESTRICTION, yes thats right. it is what the heads/valves are holding back....so its not just as simple as saying a b16 does this so a VQ must be the same.....
I say talk to your tuner and come to a conclusion with them.......afterall if it blows up surely you'll blame them first.
tom
Let us put things into perspective, I know boost is just one variable, but for an average joe whos car is on the street 98% of the time and maybe go to the strip here and there (Only a handful of guys here actually regularly track their built motor) then 600whp is more than enough (I dont even find enough space on the street to run my pathetic 370whp car).
Now let us look how we can attain that power goal. IMO 600whp can be done around 15psi with head work, cams and maybe increase redline and 9:0:1 or 9:5:1 and still be safe. Why do you need an 8:0:1 if your properly built motor can hit your power goal in just 15psi? If I wanted over 700whp with lots of boost (above 20psi) then maybe but how many guys run 700+whp here? I hear people complain about traction so is it really wise to have 700-800whp monster on the street unless you want bragging rights?
To each his own and everyones goal is different so for some 8:0:1 is better but for some 9:5:1 or 9:0:1 is low enough to actually hit their goals and some without hurting their motor... just my .02
03-05-2009, 07:27 AM
#26
I don't understand this statement. Over 500rwhp isn't bragging but over 600 is? Every year the bar is raised, and although it's not always possible to "use" all those "extra" HP, I certainly like the fact that I can tap into it when desired.
03-05-2009, 07:44 AM
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There is a lot of useless crap being strewn about in this thread. The FACT is lower compression does NOT hurt your power output per pound of boost nearly as much as the OP claimed.
Lower compression not only allows you to run more boost, but it allows more timing advance at any given boost level. Running stock 10.3:1 compression on a built motor would be retarded with the safety margin and minimal power loss from dropping the comp to 9:1.
Why do FI cars run lower compression??? Because the safety margin advantage far outweighs the small power bump that you get from higher compression.
Lower compression not only allows you to run more boost, but it allows more timing advance at any given boost level. Running stock 10.3:1 compression on a built motor would be retarded with the safety margin and minimal power loss from dropping the comp to 9:1.
Why do FI cars run lower compression??? Because the safety margin advantage far outweighs the small power bump that you get from higher compression.
03-05-2009, 07:46 AM
#30
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I didnt say you can ran 500whp and go WOT all you want, granted I dont have a 500whp but with a right suspension setup/alignment/tires then it will be a lot more easier to control than a 700whp.
03-05-2009, 07:58 AM
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If you read the entire thread I said I prefer running in the low 500whp coz that seem to be much more usable on the street than something above 600whp. I'm posting base on my need/want so it may not apply to everyone. My choice of 9:0:1 9:5:1 compression piston is also base on my power goals.. gees you guys just need to relax.Edit:
before the someone say that I will have the urge to turn up my boost and want to venture above 600wHP then I'm telling you now I WONT!!! I've been running my pathetic 370whp for almost 2 years and running the same boost and I'm fine. At 500whp I'll be happy and will not want more... I have better self control than some I guess...
Last edited by athenG; 03-05-2009 at 08:03 AM.
03-05-2009, 08:02 AM
#33
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If you read the entire thread I said I prefer running in the low 500whp coz that seem to be much more usable on the street than something above 600whp. I'm posting base on my need/want so it may not apply to everyone. My choice of 9:0:1 9:5:1 compression piston is also base on my power goals.. gees you guys just need to relax.
03-05-2009, 08:05 AM
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been talking and reading some of the experience of other guys who are running this power. As a matter of fact some prefer to lower their boost and stay just north of 400whp.
03-05-2009, 08:16 AM
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I've been low 400s and now I'm low to mid 500s (based on boost I run), and I don't have ANY problems with traction unless it gets cold out. I'm running reduced rear negative camber and a sticky tire though...
I don't know how much higher I'd want to go than what I'm at now on the street though.
03-05-2009, 08:24 AM
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Until you can speak from your own experience try not to have an argument about what power level is "better" to run on the street.
I've been low 400s and now I'm low to mid 500s (based on boost I run), and I don't have ANY problems with traction unless it gets cold out. I'm running reduced rear negative camber and a sticky tire though...
I don't know how much higher I'd want to go than what I'm at now on the street though.
I've been low 400s and now I'm low to mid 500s (based on boost I run), and I don't have ANY problems with traction unless it gets cold out. I'm running reduced rear negative camber and a sticky tire though...
I don't know how much higher I'd want to go than what I'm at now on the street though.
Just like you said, mid 500whp is manageable on the street. There are many members here that are running 500whp, 600whp and a few north of 700whp and the consensus are low-mid 500whp is pretty manageable on the street. This is what I have been saying all along and that is why I just prefer running 500whp. You are giving me a hard time not having experience on driving a 500whp yet you already confirmed my thought that 500whp is easier to control on the street. I also never said I will run stock 10:3:1 piston on my build and I did a quick search and on your older build and you were at least running 9:0:1 on your early build.
