Let's let 50q's get the first crack at answering this. I am being told that I'm too ignorant to undestand this stuff.
Boosting on 10.2 CR
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- boost compression ratio
Let's let 50q's get the first crack at answering this. I am being told that I'm too ignorant to undestand this stuff.
Benz
It doesn't work like that. What everyone is fighting is the limit you can compress the charge before it detonates timing not withstanding.
I lifted one of my responses to a thread on the NE Cobra section with some edits rather than re-writing it and should clear a few things up for you.
It's "charge volume".
A flat top piston mod motor chamber volume not including deck height and head gasket thickness is 52 cc's, A dished Terminator slug adds another 17 cc of charge volume to the chamber which is a 30% increase. That translates directly on how much fuel the engine can process before the point of detonation with most of the added energy going directly to the crack shaft. The laws of physics comes into play here and to argue otherwise is going to be an uphill battle. Under no circumstances would I choose to use flat top pistons in a blown application (with the exception of E85) and to do so you are leaving hp on the table.
A 99 Cobra engine with a forged bottom end and a PD blower will hit a brick wall around 425 hp on pump gas where an 03/04 can get close to 600
idea: Hay! that's about a 30% power advantage imagine that) Switch both engines to race gas and that gap will still be there. What ever combo you can come up with that 30% charge volume disadvantage thing will be literarily impossible to overcome.For a centrifugal or turbo bumping the compression will help reduce the effect of lag and a poor throttle response which is a good idea plus the fact they make mad hp "on top" to begin with but the more you add the less potential the motor will have not being able to pack more boost into the engine. 9:1 tops for me with the exception of E85 which would probably gets me close to 11:1. A PD blown car works great at 8.5:1 and to raise it is pointless and detrimental...........IMO
I modeled this in CAD to giver you a better idea on how this relates to the mod motor. These are dimensionally accurate including the volumes.
I hope that helps.
Regarding your purchasing dilemma. If your finances are tight wait until your on better footing. Terminators are generally better cared for than you garden variety Mustang that gets put out on the curb once it outlives its usefulness so they will be around more than most.........or you can make one.
You forget to mention cam selection and timing of inlet valve opening and closing with exhaust overlap. Static compression is a guide but not the rule because a cam can make or break even a low compression motor
Thankyou slow, I just miss understood the main talking point.
And as to STANGER00s point, I had a small epiphany to why a cam is even changed in a boosted mod motor. If a cam is used in a N/a motor to boost VE, is its purpose the same in a boosted car? Why not crank up the boost just more to hit the amount of VE you want? I know eventually you will starting pinging
With detonation once you hit a certain boost level, or even the adiabatic efficiency of the s/c
Will not allow anymore power to be gained past a certain point, but if the goal is just a regular high hp street car rather than a 1/4 mile king, why put in a cam?
And as to STANGER00s point, I had a small epiphany to why a cam is even changed in a boosted mod motor. If a cam is used in a N/a motor to boost VE, is its purpose the same in a boosted car? Why not crank up the boost just more to hit the amount of VE you want? I know eventually you will starting pinging
With detonation once you hit a certain boost level, or even the adiabatic efficiency of the s/c
Will not allow anymore power to be gained past a certain point, but if the goal is just a regular high hp street car rather than a 1/4 mile king, why put in a cam?
A 99 Cobra engine with a forged bottom end and a PD blower will hit a brick wall around 425 hp on pump gas where an 03/04 can get close to 600
.
whatever you smoke please share with us because it hits hard :lol:
Haha! I swear! I bought the Lethal conversion, which was ~1k with 485lph pumps. I am sitting at 32k miles now and I did all of the work myself. I do all of my car work myself. No regrets since I am running two tunes: one for e85 and one for 93. I am moving to MD, so I may need the 93 tune eventually.
My point was not to forget about dynamic compression.
It's a shame you are leaving. I was really looking forward to bothering a local for all things so-cal has to offer to cobra guys. Def see a lot more lambos / bentlys than I see svt's. Good luck with the move, and thanks for the response!:rockon:
True statement. I didn't want to get into that because it starts to complicate things quite a bit. Cam selection will not have has as much effect as the amount of boost level which will vary in a pretty dramatic way. Figuring dynamic compression with a bower in the mix will be like trying to catch a moving bus.
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My head hears from reading your dump posts , looks like you have 0 experience with these cars just posting out of your a$$
A 99 Cobra engine with a forged bottom end and a PD blower will hit a brick wall around 425 hp on pump gas where an 03/04 can get close to 600
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I know few 99-01 Cobras that make 440-450 rwhp on stock motors and tiny stock 03-04 Eaton blowers running pump gas . I know a 01 Cobra with built motor [flat tops even more CR then stock ] 2.8KB that makes 560rwhp on pump gas . My brothers 4.6DOHC motor with .20 over flat tops [around 10.5:1 CR] made 440rwhp thru auto trans with loose TC running non intercooled blower on pump gas .
you seriously think you will make 30% more power than me
Let's do this ,
you have motor with 8.5:1 CR and 2.3 PD blower on race gas
I have motor with 10.5:1 CR and 2.3 PD blower on race gas
I'll make more power then you , more TQ , way better power band , run cooler , and get better MPG
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:dw:
I am 100% sure my 99 Cobra can make 600+ on pump gas without even beginning to push the RPM limit of the 2.3L Whipple. I have video after video of my car running against similar combos with 2-3 times the amount of boost. I have timeslips, data, and tangible results.
Enough photos and enough talk. Produce a working model.
Enough photos and enough talk. Produce a working model.
Benz
A 99 Cobra engine with a forged bottom end and a PD blower will hit a brick wall around 425 hp on pump gas where an 03/04 can get close to 600
All these statements prove your stupidity. I don't need to explain myself, apparently you should stop explaining yourself as it keeps getting worse. Do I really need to explain more. You have argued with everyone in this thread and some reason you still feel correct.
Very good advice! :thumbsup:
Yep. 100% correct! :thumbsup:
Wow, you don't venture out much do you? There are TONS of Coyote's making over 600 on pump gas.
Go ahead and start a thread and ask how many are over 600 on pump gas?
2011-2014 Mustangs - SVTPerformance
Here's a quick example of one now.
[youtube_browser]_R-XEyWHsp4[/youtube_browser]
[youtube_browser]_R-XEyWHsp4[/youtube_browser]
04 sleeper, my question is why? This car with only 5.4psi and 11:1 comp ratio made 609rwhp. My brain is wanting to know why wouldn't a car with the same exact setup, but only lowering the comp ratio to say 9:1 and increasing the boost to safely run on the same fuel, be able to make a ton more power. It seems there would be a lot more air and fuel to make a bigger bang with the low comp ratio setup than the high comp ration. Thanks
You also need to consider how much less heat is being put out by the turbo. Also that motor is running more efficient without a power adder.
agreed-this guy knows nothing,svt god?you have to be kidding me-you want to learn something? come to the shootout and we will teach you something:bash:
If you were running 8.5:1 with your engine combo you would already be there
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