twin turbo vs supercharger
01-27-2011, 03:26 PM
#16
Race Director
01-27-2011, 09:01 PM
#18
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NEVER supercharge or try to turbo a NA car. Sell it and get the real thing. You will be MUCH happier in the short and long term ($$$s still in your pocket, car performing well and reliable, and a little thing we call resale). A 993TT with a modest amount of work is easy over 500HP, instant boost, and more than most people can handle...
where were you when I needed you...
01-28-2011, 08:53 AM
#19
Nordschleife Master
I sure hope the driveshaft to the front on the AWD turbo is bigger than the (non-existant) driveshaft to the front on the RWD C2
(just breaking *****)
yeah Bob, I know you have a lot of experience here, but I'm not seeing that.
From my knowledge, if you start with a stock 400bhp Turbo, you'd need:
1. Turbos...560bhp would need k24s at least, and those run about $3k alone. Add $200 for all the swap parts like exhaust rings, studs, and nuts.
2. Exhaust parts, including cat pipes or deletes and probably muffler deletes. I suppose you could go with the AWE test pipes, so lets call it $650.
3. You'd need some larger injectors, lets call it $300 there
4. Probably need a new fuel pump at $250
5. Diverter valves at $250
6. Tuning...looking at about $1000+ for a reflash by mail or at least that for in person tuning.
So with an ear splitting exhaust, and a hondaish torque curve, you may hit that figure, but you'd be out at least $5700, assuming you can do all the labor yourself.
If you can do it CORRECTLY for $4000, tell me how and I'll do it tomorrow.
(just breaking *****)yeah Bob, I know you have a lot of experience here, but I'm not seeing that.
From my knowledge, if you start with a stock 400bhp Turbo, you'd need:
1. Turbos...560bhp would need k24s at least, and those run about $3k alone. Add $200 for all the swap parts like exhaust rings, studs, and nuts.
2. Exhaust parts, including cat pipes or deletes and probably muffler deletes. I suppose you could go with the AWE test pipes, so lets call it $650.
3. You'd need some larger injectors, lets call it $300 there
4. Probably need a new fuel pump at $250
5. Diverter valves at $250
6. Tuning...looking at about $1000+ for a reflash by mail or at least that for in person tuning.
So with an ear splitting exhaust, and a hondaish torque curve, you may hit that figure, but you'd be out at least $5700, assuming you can do all the labor yourself.
If you can do it CORRECTLY for $4000, tell me how and I'll do it tomorrow.
01-28-2011, 08:58 AM
#20
Nordschleife Master
Actually taking the front drive system OUT of a spirited Turbo will give you more fun than you can imagine.... (also saves 150ish lbs)
01-28-2011, 12:11 PM
#21
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I have always wondered about that move. I understand that the AWD's seem to understeer a bit, is that predominately why? If I had 400HP to put onto the road, it makes sense to have all 4 wheels participate unless I like to light up the rear wheels.....what is the typical reasoning for this?
Cheers,
Mike
01-28-2011, 12:23 PM
#22
Race Director
Actually u can do this EASY with K16 hybrids. Have a misubishi wheel installed (about $2K for work), have proper blow off valves, and programming ($1400), and a 5 BAR FPR. Thats it. So no does not include labor. About 6-8 hours probably at most shops. 4 if they have actually seen a 993TT before and removed a turbo.
I struggle here.
Even with a relatively low BFSC of .6, 560bhp with max fuel pressure of 73.5 (5 bar) and a high (imho) injector duty cycle of 90%, you are looking at needing 48lb/hr injectors as opposed to the 37.7 lb/hr that come stock.
That leaves basically no margin for error.
if you were to do it "properly" (again imho), with same fuel pressure, an 80% duty cycle, and a bsfc of .65, you are looking at 58lb/hr injectors.
I'm not sure what the flow level of the fuel pump is, but at 73psi, the volume delivered is dropping substantially from the 3.8bar stock pressure.
Further, how are you running blow off valves (not bypass valves) on the draw-thru 993TT maf? That would be dumping metered air...causing the car to go pig rich.
I'm not familiar with the k16 hybrids you are speaking of, but to get that kinda power, I'm assuming you're gonna spin them to the tune of 1.5 bar of boost, which from my knowledge brings them well out of their compressor efficiency map, but again, I'm not familiar with this specific package.
Also, you are saying that all this can be done on stock cats/mufflers?
I'm gonna make a new thread with quotes from here so we can stop sidetracking this thread.
01-28-2011, 12:25 PM
#23
Race Director
Hey Bob,
I have always wondered about that move. I understand that the AWD's seem to understeer a bit, is that predominately why? If I had 400HP to put onto the road, it makes sense to have all 4 wheels participate unless I like to light up the rear wheels.....what is the typical reasoning for this?
Cheers,
Mike
I have always wondered about that move. I understand that the AWD's seem to understeer a bit, is that predominately why? If I had 400HP to put onto the road, it makes sense to have all 4 wheels participate unless I like to light up the rear wheels.....what is the typical reasoning for this?
Cheers,
Mike
this of course assumes you are just slapping the throttle open. If you have the ability to feather the throttle, you should be able to avoid wheelspin almost entirely.
01-28-2011, 01:08 PM
#24
Rennlist Member
NEVER supercharge or try to turbo a NA car. Sell it and get the real thing. You will be MUCH happier in the short and long term ($$$s still in your pocket, car performing well and reliable, and a little thing we call resale). A 993TT with a modest amount of work is easy over 500HP, instant boost, and more than most people can handle...
https://rennlist.com/forums/attachme...yno-10-psi.jpg
Cost wise it's a tough call. Both cars came nicely configured they just needed some love. Choose wisely and you will get a deal with either.
I know some mechanics that love the SC'd 993. They rave about the instant on power and smoothness.
The cheapest path to any of the above is to sell yours and buy one done. Drive and evaluate each based on what's important to you. I found a real bargain buying a turbo'd C4S because as you pointed out it resale is an issue with such a thing.
Last edited by MarinS4; 01-29-2011 at 01:19 AM.
01-28-2011, 01:54 PM
#25
Hey Bob,
I have always wondered about that move. I understand that the AWD's seem to understeer a bit, is that predominately why? If I had 400HP to put onto the road, it makes sense to have all 4 wheels participate unless I like to light up the rear wheels.....what is the typical reasoning for this?
Cheers,
Mike
I have always wondered about that move. I understand that the AWD's seem to understeer a bit, is that predominately why? If I had 400HP to put onto the road, it makes sense to have all 4 wheels participate unless I like to light up the rear wheels.....what is the typical reasoning for this?
Cheers,
Mike
Cheers,
Joe
01-29-2011, 04:09 PM
#26
Rennlist Member
I am having a SC installed in my C2S now. For me, I had my car where i wanted it with other mods over the past years and knew its history perfectly and wanted to keep it - but keep modding it. I'm not worried about resale. I could have found a similar low miles turbo, with similar history but for a much bigger cost by the time I sold and rebought. And I still would have to make all the other mods to get it to where I wanted it. Plus I like RWD, I don't put that many miles on the car each year with our climate. If many years down the road it needs work, its just an opportunity for a better engine build, right?
For a stock turbo vs. a SC car it makes sense that the reliability might be slightly better from the factory (guessing). But if you boost the turbo to much over its stock design as is being suggested, it would stand to reason that you've then compromised the stock turbo car reliability by a similar margin ?(again the original poster wasn't asking about a boosted turbo though).
For a stock turbo vs. a SC car it makes sense that the reliability might be slightly better from the factory (guessing). But if you boost the turbo to much over its stock design as is being suggested, it would stand to reason that you've then compromised the stock turbo car reliability by a similar margin ?(again the original poster wasn't asking about a boosted turbo though).
03-01-2011, 05:46 AM
#28
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yeah Bob, I know you have a lot of experience here, but I'm not seeing that.
From my knowledge, if you start with a stock 400bhp Turbo, you'd need:
1. Turbos...560bhp would need k24s at least, and those run about $3k alone. Add $200 for all the swap parts like exhaust rings, studs, and nuts.
2. Exhaust parts, including cat pipes or deletes and probably muffler deletes. I suppose you could go with the AWE test pipes, so lets call it $650.
3. You'd need some larger injectors, lets call it $300 there
4. Probably need a new fuel pump at $250
5. Diverter valves at $250
6. Tuning...looking at about $1000+ for a reflash by mail or at least that for in person tuning.
So with an ear splitting exhaust, and a hondaish torque curve, you may hit that figure, but you'd be out at least $5700, assuming you can do all the labor yourself.
If you can do it CORRECTLY for $4000, tell me how and I'll do it tomorrow.
- K24s stock will get you to <500bhp. So you need to modify them to hybrids, add $2-4K to the purchase price.
- Good Exhaust and cats will cost more like $2k ?
- You need a variable Fuel pressure regulator
- You definitely need injectors
- The 044 fuel pump is ~ $400 nowadays I think
- You need camshafts. Stock ones don't take you > 500hp no matter what turbos or boost you run ($2k+ ?)
- You need to refresh your valvetrain with new springs at a minimum
- You need a boost controller most likely unless you can get someone to tune your Motronic based on variable boost, then it will be $3-4k for the programming
- You need upgraded head studs
- You need cylinder to head niro rings (proper machining and parts cost $$)
- You need a full clutch assembly ( $3-4k ?)
- You can get away with stock intercooler for limited runs
- You need a second oil cooler ($1k?)
- You need to check your (leak down and compression numbers) and most likely at least change piston rings. Yes you can get away with it, but for how long will it last.
This is what I can remember. Do the math.
You can slap a couple of hybrid turbos, run a boost controller at 1.3 bar and programming and think you have 500bhp (no way more), in reality you "might" for a few seconds, do it long enough and you will need an engine rebuild very soon.
Tjangi, I take it you are not happy with your setup? Could you please share what is not working as expected. Thanks
03-01-2011, 08:59 AM
#29
Three Wheelin'
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Tjangi, I take it you are not happy with your setup? Could you please share what is not working as expected.
IMHO - If you have the money, you should buy a real turbo and start from there. You can get more HP per buck from a turbo engine than a NA engine (with same $$$ investment)
03-01-2011, 10:23 AM
#30
Race Director
Assuming one wants sustainable power and an engine that will last reasonably long ...let me add the following for mid-500s:
- K24s stock will get you to <500bhp. So you need to modify them to hybrids, add $2-4K to the purchase price.
- Good Exhaust and cats will cost more like $2k ?
- You need a variable Fuel pressure regulator
- You definitely need injectors
- The 044 fuel pump is ~ $400 nowadays I think
- You need camshafts. Stock ones don't take you > 500hp no matter what turbos or boost you run ($2k+ ?)
- You need to refresh your valvetrain with new springs at a minimum
- You need a boost controller most likely unless you can get someone to tune your Motronic based on variable boost, then it will be $3-4k for the programming
- You need upgraded head studs
- You need cylinder to head niro rings (proper machining and parts cost $$)
- You need a full clutch assembly ( $3-4k ?)
- You can get away with stock intercooler for limited runs
- You need a second oil cooler ($1k?)
- You need to check your (leak down and compression numbers) and most likely at least change piston rings. Yes you can get away with it, but for how long will it last.
This is what I can remember. Do the math.
You can slap a couple of hybrid turbos, run a boost controller at 1.3 bar and programming and think you have 500bhp (no way more), in reality you "might" for a few seconds, do it long enough and you will need an engine rebuild very soon.
Tjangi, I take it you are not happy with your setup? Could you please share what is not working as expected. Thanks
- K24s stock will get you to <500bhp. So you need to modify them to hybrids, add $2-4K to the purchase price.
- Good Exhaust and cats will cost more like $2k ?
- You need a variable Fuel pressure regulator
- You definitely need injectors
- The 044 fuel pump is ~ $400 nowadays I think
- You need camshafts. Stock ones don't take you > 500hp no matter what turbos or boost you run ($2k+ ?)
- You need to refresh your valvetrain with new springs at a minimum
- You need a boost controller most likely unless you can get someone to tune your Motronic based on variable boost, then it will be $3-4k for the programming
- You need upgraded head studs
- You need cylinder to head niro rings (proper machining and parts cost $$)
- You need a full clutch assembly ( $3-4k ?)
- You can get away with stock intercooler for limited runs
- You need a second oil cooler ($1k?)
- You need to check your (leak down and compression numbers) and most likely at least change piston rings. Yes you can get away with it, but for how long will it last.
This is what I can remember. Do the math.
You can slap a couple of hybrid turbos, run a boost controller at 1.3 bar and programming and think you have 500bhp (no way more), in reality you "might" for a few seconds, do it long enough and you will need an engine rebuild very soon.
Tjangi, I take it you are not happy with your setup? Could you please share what is not working as expected. Thanks