American or European?

[Deusxmachina]

Originally Posted by 1Kurgan1

That has always been one of my favorite pictures. But also one thing that I'm wondering is how stout is the drivetrain on DSM's. I just can't imagine them standing up to that kind of power and pulling off good launches, something eventually has to give. And a tranny failure is just as bad as a engine failure in my book. Part of the reason I got out of the SHO game, after tossing 3 differential pins through tranny casings it just got old.

Well, you know how it is, the more you beat on it, the more chance of it breaking. If a car lives its life a 1/4-mile at a time, every mile on it is going to be pretty rough compared to a daily-driver or even weekend-warrior. Put slicks on any car, launch off the rev-limiter, and see how long it lasts, y'know?

And that's what a lot of people do with AWD cars. They launch the piss out of them constantly, track, highway onramps, stoplights, and then they are surprised when they break something. Just because you can do a 1.6 60-foot on street tires doesn't mean you should. Even aftermarket stuff can have problems. I remember a Mustang guy with his new Tremec trans, had it for a week, ran an 11 or two at the track, it broke, and he was so mad he slammed his door closed hard enough to break the window.

I'd say anyone with a mild DSM, say, around 350bhp, has almost nothing to worry about, it may as well be a stock car unless he's beating the piss out of it. And that's a mid-12 car, which sounds slow when talking about 11s and 10s and all that, but a solid-12 car is pretty wicked for most people on the street. The first Viper "only" did 12s@112 or so. Not overly impressive, especially nowadays.

So much depends on how you drive it. I was talking to a local guy with a I think it was a 610whp Talon and asked him about breaking. He said it wasn't really a problem at all for the way he drives, but if he started constantly launching off the two-step using anti-lag, yeah, it'd probably become a problem.

I've had my fill of quick FWDs and don't plan on ever having another one. Torque-steer, wheel-hop, no traction.... they can be a load of fun even at lower power levels, but I think the fun comes more from "this is scary" kind of fun, which isn't the good kind of fun. If you floor a strong FWD in a low gear, be ready to put a turn signal on because you might be making an unintended lane change. Is that fun? In a way, it is. On the flipside, AWD can be downright boring.

I read the following a long time ago, and it's always stuck with me, and fortunately it wasn't too hard to scrounge up. The guy had a 300-some hp AWD Talon and raced it a lot in SCCA or whatever before getting a Porsche 944 turbo and driving and racing that.

>Maybe we ought to tear apart a new Porsche Turbo... it has 400hp from the
>factory and is bullet proof as far as I've heard. The Nissan Skyline GTR
>also has AWD and makes gobs and gobs of power. It can run 10's on street
>tires.

As far as the Porsche goes, the weak link there is the clutch. No one
has ever broken a transfer case or rear-end on a stock clutch in a DSM.
There was a fellow I know with a new 911 TT that took it drag racing.
He revved it up to 6000rpm, dumped the clutch, the car's clutch slipped
all the way down the track. He ran 15.X @ 110mph, it was pretty gross.
The car stunk when he brought it back. Well, that car is now traded in
and he's waiting for his 911 Turbo S to arrive.
The Skyline on the other hand has an awesome drivetrain, which can handle
some serious power.

>In last month's Turbo, there is a Hynudai looking rally car that has what
>looks like a Mitsubishi turbo engine. It has 400+ hp and AWD. What ever
>drivetrain it has, it hooks up to a Mitsubishi engine. I think TAD worked on
>the car. I'll go do some research!

If you take a car to a gravel road, you can put 700hp down with our
stock drivetrains and probably a stock clutch, the tires will spin, not
the clutch or the drivetrain. These guys only have to launch perhaps once
every four to five races on ashpalt and even that's on cold slick tires
that spin easily. For the record, I never broke any drivetrain parts on
my car and I really sh*t kicked that poor thing, but then I don't launch
off the rev limiter either

I kind of want to get something off my chest here, so please allow me to
vent. How the hell do people think the drivetrains in these cars are
weak? You can do a 12 second run at 110mph without breaking anything
and people consider this weak? Most AWD cars that come from the factory,
including big $$ Porsches will destroy their clutch if you do this and if
you get a better clutch, it will break the gearbox or an axle. Many a
911 Turbo and 944 Turbo have broken axles from launching hard.

I think
some people don't understand the forces involved in launching a 3200lb
AWD car with 350hp. If you don't do a 4500rpm launch at the track,
YOU WILL NOT break parts, you won't be as fast, but you won't break
parts. I know Ferrera said that he was still breaking parts even with
granny shifts, but that I can guarantee was his clutch choice. Even a
granny shift with a 4-puck clutch will be too much stress for the
drivetrain. But, I have to give credit to Ferrera for trying different
things. I know we'll be ordering a carbon fibre driveshaft to reduce
the rotating mass down there. I broke three diffs in my FWD car from
a poor choice of parts, but I learnt too

Now that I own a RWD car, I feel kind of sorry for my old Talon. In the
Porsche, when you shift into second hard, it goes all squirmy and the tires
spin like crazy. The AWD obviously stopped this from happening, but the
clutch I'm sure took a hammering as did the transfer case and diffs.

I remember reading an english magazine where they took a 400hp Escort
Cosworth and painted a white stripe down the center driveshaft. They
took it up the limiter and dropped the clutch. The car did a high 3
second 0-60 and did the 1/4 mile in something like low 12's @ 112mph.
The white stripe had warped around the driveshaft! We should do this
to Dave's car one day, maybe he can wrap it around a couple of times.

[Wile E]

As far as the DSMs, 400whp seems to be the general consensus on the stock drivetrain's limit. That's with the "weekend warrior" type of use.

As Deus said, it depends largely on the driving style tho. Drive harder, and it will die quicker or handle less horsepower, drive easier, and it will last longer or handle more horses. 400whp just seems to be about the average people are able to achieve with reasonable reliability.

Hell, you can even destroy a stock DSM's drivetrain if you beat on it constantly.

[1Kurgan1]

the gas, no breaking my tires will pop loose without a problem. So really just takes stress off the drivetrain, but now that I mentioned that, all I have really had is FWD cars, at least any car that was mildly fast.

My SHO's were torque steer monsters, but the GTX has none, I can even lay on it through a corner and not an issue, tires might light up, but the thing gives nice flat straight power, really shocking and I should be knocking on 12's so if it was going to have it, it should have shown some sign by now.

But pretty impressive to hear they can hold that kind of power stock.

[Deusxmachina]

Originally Posted by 1Kurgan1

the gas, no breaking my tires will pop loose without a problem. So really just takes stress off the drivetrain, but now that I mentioned that, all I have really had is FWD cars, at least any car that was mildly fast.

My SHO's were torque steer monsters, but the GTX has none, I can even lay on it through a corner and not an issue, tires might light up, but the thing gives nice flat straight power, really shocking and I should be knocking on 12's so if it was going to have it, it should have shown some sign by now.

But pretty impressive to hear they can hold that kind of power stock.

Did you get a lot of wheel-hop with the SHO? That's arguably what really breaks FWDs. It doesn't feel good when you're doing it, that's for sure! Would rather spin 'em than wheel-hop.

...that's an amusing answer to a problem...
"I keep breaking my FWD, what should I do?"
"Just launch harder, and make sure you spin the tires."

Sucks that they don't make things like the Cobalt RWD. AWD can be boring, and FWD can be annoying. Now there was a car... Merkur XRT4i. Not the nicest thing for cruising, maybe due to the short wheelbase, but it had two great things: RWD and turbocharged.

A GTX what? Mazda?

[Wile E]

Originally Posted by Deusxmachina

Did you get a lot of wheel-hop with the SHO? That's arguably what really breaks FWDs. It doesn't feel good when you're doing it, that's for sure! Would rather spin 'em than wheel-hop.

...that's an amusing answer to a problem...
"I keep breaking my FWD, what should I do?"
"Just launch harder, and make sure you spin the tires."

Sucks that they don't make things like the Cobalt RWD. AWD can be boring, and FWD can be annoying. Now there was a car... Merkur XRT4i. Not the nicest thing for cruising, maybe due to the short wheelbase, but it had two great things: RWD and turbocharged.

A GTX what? Mazda?

Grand Prix GTX, if I'm not mistaken.

And have you seen the New Hyundai Genesis Coupe? RWD, and the base model comes with a detuned to 210HP 4B11 (engine found in the Evo X). I'm very curious to see what comes of this car in the aftermarket.

[Deusxmachina]

Originally Posted by Wile E

Grand Prix GTX, if I'm not mistaken.

And have you seen the New Hyundai Genesis Coupe? RWD, and the base model comes with a detuned to 210HP 4B11 (engine found in the Evo X). I'm very curious to see what comes of this car in the aftermarket.

Didn't think of that. Thought all the Grands Prix were GTPs.

The Genesis was rumored to get a turbo4, but the website just says a V6 and V8.

[T3hPwn3r3r]

Genesis coupe has a turbo 4, but Genesis coupes are notable (Korean spec) at least for horrible build quality and airbag failure.

One reviewer said "Do they think the Korean people are fools? That we don't know good cars?"

[Wile E]

Originally Posted by Deusxmachina

Didn't think of that. Thought all the Grands Prix were GTPs.

The Genesis was rumored to get a turbo4, but the website just says a V6 and V8.

I might be mistaken about his car.

As far as the Genesis, it comes with either a 2.0L turbo 4, or a 3.8 V6.

http://www.hyundaiusa.com/vehicle/Ge...esisCoupe.aspx

[1Kurgan1]

Originally Posted by Deusxmachina

Did you get a lot of wheel-hop with the SHO? That's arguably what really breaks FWDs. It doesn't feel good when you're doing it, that's for sure! Would rather spin 'em than wheel-hop.

...that's an amusing answer to a problem...
"I keep breaking my FWD, what should I do?"
"Just launch harder, and make sure you spin the tires."

Sucks that they don't make things like the Cobalt RWD. AWD can be boring, and FWD can be annoying. Now there was a car... Merkur XRT4i. Not the nicest thing for cruising, maybe due to the short wheelbase, but it had two great things: RWD and turbocharged.

A GTX what? Mazda?

Nope, no wheel hope, they are just famous for tossing diff pins. I never had any pop from a stop, those cars have major traction issues, I think the fastest 60 ft time I have ever heard of out of a SHO is like 2.1 on DR's. The guys pushing 450 - 500whp run like 13.2 at 125mph, lol. They are also famous once the 350tq mark to blow 3rd gear. The tranny design is the MTX IV which was based off an escort tranny Seriously don't know what Ford was thinking, lets send a motor to Yamaha to get built then use a damn escort transmission, sounds like a great idea! My last SHO I even welding in the diff pins and they still worked their ways out, just very slowly, they didn't blow holes in my transmission, they just created a big 1mm holes all the way around the casing :/

And yep, Grand Prix GTX, same as a GTP, just diff hood, 17" rims, GTX floormats/keyring, and a few other looks goodies from the factory, it's got full suspension work though, so many thats why, I can actually toss the backend out on corners if I want with a FWD But GTP's are pretty famous for being great 1/4 cars for FWD, I hear of a lot of people pushing 1.9 - 2.0 60ft with street tires, thats pretty sick for a FWD.



And yeah the XRti4's were interesting cars, butt ugly, could be made to look decent, really small RWD car though, wish we would see more of that, partially why I think the BMW 135i is so damn wicked.

[Deusxmachina]

The last two times I searched for Hyundai Genesis, I only saw the luxo version. Guess I should've looked harder. Looks good so far. A quick glance shows differing reports on what's actually inside the engine. One site says he talked to three of the most informed guys on the subject, and they basically said the motor is somewhat similar but weaker. Guess we'll see.

[1Kurgan1]

The Genesis coupe just came out, the 3.8L has been the comparo for the V6 Camaro's, been on a few mag covers, it's slightly quicker because the weight advantage.

[Wile E]

I'd rather have the 2.0 turbo Genesis. The 4B11 already has huge aftermarket support, thanks to the Evo.

[1Kurgan1]

But whats done to shave off 74hp from the Evo and 83hp from the Caliber? I'm doubting it's just boost drop, as the turbo would most likely barely be putting out anything then. It even looks like the Evo has a lower compression slightly.

[Deusxmachina]

The Genesis has a giant scrunch on the exhaust. That won't help things.

It's quite possible a large part of it is from lower boost. I don't know what the Genesis is pumping out, (nor what kind of turbo it has), but if it's only like 10psi, 10psi is girly boost.

[Wile E]

Restrictive exhaust and a smaller turbo with less boost would be my guesses. Maybe milder cams and less aggressive timing. The Evo X peaks at 23psi stock, and tapers down to around 14psi near redline. Knock that value down to 7-10psi, across the board, and you have a huge chunk of power gone. Add that to a restrictive exhaust, and the lower boost alone may be able to pull it off, without even needing to change the cams or engine timing.

A good baseline to use to figure these things out in a rough manner is to realize that power added by boost, is generally pretty linear. Not perfectly linear, but close enough to make decent estimates. If you take a naturally aspirated engine, adding 14.7lbs of boost doubles the HP. So a 200HP NA motor, makes near 400HP with 14.7psi, provided the engine is able to handle the boost, and the exhaust is up to the task of flowing 400hp worth of air. 22.05psi (+7.35psi AKA: half of 14.7) would take that another 100HP up. Believe it or not, iirc, it was Muscle Mustangs and Fast Fords that did the extensive testing on this that I read, on a Focus to boot.

And by Caliber, did you mean the Dodge Caliber, Kurgan? If so, completely different engine.

[1Kurgan1]

Ah I didn't realize they ran that much boost stock, suppose it is possible for them to cut a lot out, thats pretty crazy though, how much can someone reliably make on the street with those things, I can't imagine adding much more boost without having to run some pretty pricey gas or take other methods like advancing the timing which will kill the performance anyways.

But yep meant the Caliber, but I guess thats a 4B12, I guess there is a 4B10 motor too, not sure in what though. So I wonder what beyond displacement is the diff between the 2 or if the 4b12 can be bored farther, if so 4b12 block + 4b11 head = fun

[Wile E]

Originally Posted by 1Kurgan1

Ah I didn't realize they ran that much boost stock, suppose it is possible for them to cut a lot out, thats pretty crazy though, how much can someone reliably make on the street with those things, I can't imagine adding much more boost without having to run some pretty pricey gas or take other methods like advancing the timing which will kill the performance anyways.

But yep meant the Caliber, but I guess thats a 4B12, I guess there is a 4B10 motor too, not sure in what though. So I wonder what beyond displacement is the diff between the 2 or if the 4b12 can be bored farther, if so 4b12 block + 4b11 head = fun

Well, the high boost comes at lower rpms, therefore engine load is lower. At peak engine loads, the boost is only making it to 14psi, because of the small turbo they decided to use. They emphasized tuning on response and midrange, sacrificing top end. If you bolt a better turbo on there, even if you just eliminate boost roll off, I'm willing to bet there's a fair bit more power left to be had. And 93 octane should be able to cope with 24psi fairly well. Not so sure about the 91oct California piss-water tho.

As far as 2.0 vs 2.4, it comes from both bore and stroke. The 2.0 has a bore and stroke of 86x86mm, the 2.4 is 88mm x 97mm 4B10 is a 1.8L variant.

I bet the factory 2.0 block could be bored to 88mm, but this is an open deck design, so the 86mm bore would have better strength. Considering both blocks are the same family, the length and width dimensions are probably the same, the deck height is likely what differs (which is generally the case when an engine family has a broad range of displacements).

[Deusxmachina]

Originally Posted by 1Kurgan1

Ah I didn't realize they ran that much boost stock, suppose it is possible for them to cut a lot out, thats pretty crazy though, how much can someone reliably make on the street with those things, I can't imagine adding much more boost without having to run some pretty pricey gas or take other methods like advancing the timing which will kill the performance anyways.

Depends on the compression ratio, gas, efficiency of turbo and intercooler, tune, etc. A bigger turbo is generally more efficient than a smaller one. It pumps more volume into the same psi. 10psi on a stage eleventeen turbo might be equal to, say, 20psi on what the Genesis or most cars probably come with.

Pretty standard nowadays "backyard, shadetree mechanic, daily-driver" stuff for a 4g63 AWD is around 400whp on 93 octane using a 50-trim turbo running 22-24psi or so. Something bigger like a 60-1 or 35R or whatever can generally do more horsepower, or the same horsepower at less boost. There are 500+whp on 93 octane ones running around.

E85 gas is sort of like race gas. There are 700-ish whp ones on e85. I'd mention their 1/4-mile times, but it's hard to know if they've been gutted for weight or whatever. Also, dynos can read differently on the same car, so dyno numbers aren't absolutes. Still usually in the ballpark more or less, though.

For most people with DSMs and EVOs, I'd say, pretty much regardless of turbo, 20psi is sort of the "set it and forget it" number. You'll hear comments like, "Yeah, I run 30psi at the track on good gas, could probably run mid 20s on 93 no problem, but I drive the car every day and 20psi is plenty of power and has a good margin of error if I get a bad tank of gas or something." It's like, when in doubt, just set it for 20psi.

It can be amusing when people new to such a thing hear 20psi considered to be "low boost."

[1Kurgan1]

Yeah thats pretty crazy to hear 1 1/4 atmospheric pressure being called low pressure. Interesting that the boost pressure varies, wonder how big of a difference it makes though as I am surprised they can build more boost with lower RPM's.

Really interesting to hear the boost numbers people push through these 4 poppers though, I'm use to 6's and 8's and seeing much lower numbers. Pretty crazy though.

[Wile E]

Originally Posted by 1Kurgan1

Yeah thats pretty crazy to hear 1 1/4 atmospheric pressure being called low pressure. Interesting that the boost pressure varies, wonder how big of a difference it makes though as I am surprised they can build more boost with lower RPM's.

Really interesting to hear the boost numbers people push through these 4 poppers though, I'm use to 6's and 8's and seeing much lower numbers. Pretty crazy though.

Well, small twin-scroll turbos spool very quickly. so they achieve boost with little to no lag.

And bigger turboes don't mean more efficiency, dues. It's all about design. For the most part, 10psi is 10 psi. The only thing that differs is spool speed, and heat output. If you aren't running a turbo intended for a bike engine at 10psi on a 4B11, heat output won't really be a concern, so that leaves spool time. A smaller turbo is likely to put out more power over a broader range than a larger turbo, thereby making it faster, if at the same boost levels, both share the same bearing design, and both are being used in an optimal efficiency range.

Running 10psi on a GT35, for instance, is completely pointless. A GT28 will outperform it at 10psi in almost every way.

[Deusxmachina]

Originally Posted by Wile E

And bigger turboes don't mean more efficiency, dues. It's all about design. For the most part, 10psi is 10 psi. The only thing that differs is spool speed, and heat output.
If you aren't running a turbo intended for a bike engine at 10psi on a 4B11, heat output won't really be a concern, so that leaves spool time. A smaller turbo is likely to put out more power over a broader range than a larger turbo, thereby making it faster, if at the same boost levels, both share the same bearing design, and both are being used in an optimal efficiency range.

Running 10psi on a GT35, for instance, is completely pointless. A GT28 will outperform it at 10psi in almost every way.

I said "in general" bigger turbos are more efficient. And "in general" they are, due to the heat issue you just mentioned. Keeping things simple here.

And, yes, a properly-sized-for-the-application turbo can make for a faster car due to a better powerband.

Here's an example of what I was talking about: there is not a single 4g63 2.0 making 500hp with a factory T25 turbo, regardless of psi and regardless if the engine has every other mod on the planet. It might make, oh, let's say 275hp at 20psi. Slap on a 60-1 or whatever at 20psi, and it might just do 500hp. Drop the 60-1 to 10psi, and you'll probably have a hard time not making 275 like the T25 needed 20psi to do. Over and over again, you'll (in general) see big turbos putting up bigger numbers at the same psi as a smaller turbo.

This is along the same lines as why when someone's stock turbo dies and they for whatever reason slap a honkin' big one on there with stock everything else and ask what's a safe psi to run, people will tell them not to run over 10psi or whatever even if they were running 20psi on the T-too-small (T25). If for no other reason, the stock injectors and fuel pump won't be able to keep up at more than 10psi.

Why is the person maxing out his fuel at 10psi on a big turbo when he safely ran 20psi on the smaller, stock one?

What's your take on CFM ratings? Why are CFM ratings different at the same psi?

16G 550 CFM at 14.7 PSI
18G 600 CFM at 14.7 PSI
20G 650 CFM at 14.7 PSI
60-1 725 CFM at 14.7 PSI

Btw, you're a bit of a Honda guy, right? Why do Honda owners tend to use giant turbos at crazy-low psi on such small engines?

[1Kurgan1]

Well you really couldn't count a T25 on a completely built motor, as it just doesn't supply the air. Not really anything to do with it's efficiency, it's just not built for making those horsepower figures, the way you would judge it is the power under the curve for it's peak efficiency.

Of coarse a small one would be better in a lower boost/hp situation as it's smaller, spools faster, so it gets the same amount of air their faster, the bigger one will maybe have a bit up top, but wouldn't be worth it. But thats the reason there are diff sized turbos, need to pick the right size to spool fast and supply the air the motor needs, but you both know that

[Wile E]

Originally Posted by Deusxmachina

I said "in general" bigger turbos are more efficient. And "in general" they are, due to the heat issue you just mentioned. Keeping things simple here.

And, yes, a properly-sized-for-the-application turbo can make for a faster car due to a better powerband.

Here's an example of what I was talking about: there is not a single 4g63 2.0 making 500hp with a factory T25 turbo, regardless of psi and regardless if the engine has every other mod on the planet. It might make, oh, let's say 275hp at 20psi. Slap on a 60-1 or whatever at 20psi, and it might just do 500hp. Drop the 60-1 to 10psi, and you'll probably have a hard time not making 275 like the T25 needed 20psi to do. Over and over again, you'll (in general) see big turbos putting up bigger numbers at the same psi as a smaller turbo.

This is along the same lines as why when someone's stock turbo dies and they for whatever reason slap a honkin' big one on there with stock everything else and ask what's a safe psi to run, people will tell them not to run over 10psi or whatever even if they were running 20psi on the T-too-small (T25). If for no other reason, the stock injectors and fuel pump won't be able to keep up at more than 10psi.

Why is the person maxing out his fuel at 10psi on a big turbo when he safely ran 20psi on the smaller, stock one?

What's your take on CFM ratings? Why are CFM ratings different at the same psi?

16G 550 CFM at 14.7 PSI
18G 600 CFM at 14.7 PSI
20G 650 CFM at 14.7 PSI
60-1 725 CFM at 14.7 PSI

Btw, you're a bit of a Honda guy, right? Why do Honda owners tend to use giant turbos at crazy-low psi on such small engines?

These are examples of people that are using Turbos well outside of their efficiency range. I didn't think that's what you were referring to.

CFM ratings are ok go along with maps for selecting the right turbo for your setup. I prefer the maps alone tho, as they offer a bit more info, obviously.

And I'm not actually a Honda fan. Just a guy who happened to get a good Civic for dirt cheap, and one that realizes it's dirt cheap to mod. I'd rather have a rwd Nissan, tbh. (I also own an 04 Setra Spec-V as well)

And I, to this day, still don't understand the giant turbo on low boost setups. It's a Fast and Furious type of disease. A case of the uneducated buying shit because they think it's "cool".

Personally, my goal, if I keep the Honda and swap it, is to generate somewhere around 450whp. I'll probably end up with a GT3071R or equivalent. Although, I heard rumors of a GT30RS version coming out. If it's anything the beast the GT28RS was in terms of making the same power, but spooling way faster, I'm sold, and may dedicate a build directly around it.

[1Kurgan1]

Would be impressive to see a Honda put down that much whp, even boosted don't see many putting down those kind of numbers.

[Deusxmachina]

Originally Posted by Wile E

These are examples of people that are using Turbos well outside of their efficiency range. I didn't think that's what you were referring to.

Well, there's still the case of the guy slapping a giant turbo onto an otherwise-stock car and not being able to run more than, say, 10psi or else he'll max out the fuel system. Does that mean the stock turbo was out of its efficiency range even at stock boost settings? Maybe so. And it would be no wonder why so many people take it off as soon as possible.

Just some real-world examples. A car can have various-sized turbos on it, (within reason), and they all will work "fine," albeit with some differences. The main point was 20psi doesn't necessarily equal 20psi as far as making horsepower goes.

Another thing of interest since we're throwing around the subject, is with turbo sizes and spooling is the theory that smaller, quick-spooling, spikey turbos break more parts than a bigger turbo that might make more torque but comes on smoother. More power breaks less parts? "Save your transmission, use a big turbo." Just amusing is all.

Good luck with the Honda if you go that route. I see pretty much any FWD past a certain power level as a waste of time and a form of aggravation when driving it. And, really, they become dangerous.