Is this overkill?

[WADS56]

Originally posted by demon666999
Still nobody has realy commented on my current setup And whether I chould add or take off anything. I could realy use some input.
Thanks ahead of time

I would ditch the fluid damper because as the rpm's increase the silicone (or what ever they are using) will act as a big counter weight and may cause a vibration at a certain rpm. If you are runing on the edge that could be the straw that breaks the camels back.

Also, converting a production 5.0 HO block to a 4 bolt is not worth the expence. The main webs don't have enough material to take advantage of a 4 bolt cap. The new sportsman block would be a good choice for that mod though.

[demon666999]

lx5091 you have a good point, but sadly to admit it I dont know much about all engine build up. Nor the price of the build up. I have just gotten the turbo bug and have been looking into it for the past six months. I just like the idea of all the tuning capabilities and changes that can be made at any given time to make it faster. What i meant about is this overkill is are these parts all necesary? exe. the steel crank. Well could anyone give me say an example of a n/a build up and what times i could produce.

And i realy didnt meant to argue about the turbo issue but obviously hes biased against them and i'm a biased towards them. no harm meant. Just like the idea of turbo.

[91GTturbo]

Originally posted by jim_howard_pdx
Second, why do you want a turbo charged engine? You are going to cook the inside of the engine bay. So if you are not road racing, or going for a bonneville record you should be looking at a centrifugal supercharger like a Paxton or a Velodyne unit. These are awesome units.

I built a twin turbo charged 350 small block chevy engine once. It was slow as hell to 100. Then ran 100-150 mph like a DEMON. It could not come close to beating a turbo porsche, so I sold it to a kid that wanted a twin turbo engine. By the way, just the dual waste gates for that engine cost me 750 bucks back in the 80's. Just imagine what it will cost to build a safe dual turbo today.

You can do this without the heat and damage done by turbocharging. Really, I HATE TURBOS because of what they do to the engine bay. They are a big hair dryer.

Don't take me wrong, they are the way to go if you want to go faster than 190 mph. But really, turbos are for road racing and super chargers are for off the line. NOS is for those that want a great car with power on demand.

Jim, your always good for a laugh. Please explain to me what kind of heat damage can come from a turbo? I have several friends with superchargers and my underhood temperatures are no hotter than thiers. Do I have an exact temp reading, no, but from working on both, I can get in and work under the hood as quick or quicker than they can after a run. When I get around to putting a cowl hood on my car, most have seen a decrease in underhood temps by as much as 20*. What do you think a supercharger produces besides some hp or torque, HEAT.

And as far as turbos are for road racing and blowers are for the track. I've always been told and heard just the opposite. Turbos produces massive amounts of torque, far more than a blower, which we all know is what gets you car moving. Wouldn't that be better at the drag strip? Also, wouldn't that torque get you in trouble trying to cornor on a road course. And lets mention the hp it takes to spin a supercharger and the excessive wear or the bearings vs the almost free hp produced by a turbo and no wear on the bearings.

Yes, I'm biased. I own a turbo, but their are alot of misconceptions about turbos that need to be cleared up. And as far as wastegates costing $750, lets just say as the avaliability has increased, the prices have went down. Spend some time over at www.turbomustangs.com. We have guys that built their own systems in the low 11's to mid 10's with stock headed, stock camed motors. Granted there has been some porting and bigger valves put in the heads, but I don't see any stock headed & camed supercharged motors in the 10's.

[demon666999]

[91GTturbo]

Originally posted by jim_howard_pdx
A turbo typically will not cause anything to break on the engine, rather the 1400 degree heat will super cook the engine bay. All the hoses and belts will need to be repaced every 25-50 k miles. The engine oil will be severly effected, meaning you have to run much better quality oil, and you need to change it more often.

When you shut down the engine, oil flow stops to the turbo bearings. The 1400 degree heat is still there. The oil burns and over time it will "coke" the housing and the bearing will go bye bye.

At 15 psi, you are almost doubling your volumetric efficiency of the engine. A 200 hp engine will develop about 375 hp at 6500 RPM. Go above 15 psi and your head gaskets, piston surface, valves, rings and everything will deteriorate. You can expect fairly expensive tear down and rebuilds every 100-150k miles. Many times it is cheaper to buy new turbos than fix the old ones.

A turbo is not an engine for a 19 year old on a limited budget. A twin turbo is not an engine for someone without access to dyno time, with extra money for tuning the engine for maximum power.

Really. You are not going to beat on rice rockets just because of the turbo. You beat up on competitors by having more off line torque. A 302 with decent home ported heads, cam, intake, and gears can easily run mid twelve to mid thirteen second quarters. Most rice rockets run 15.25 to 15.75 second ets. So you will have street and strip dominance without high expense.

If you want a good turbo car, look for a buick grand national. They could turn 12.1 quarter mile times with only mild modifications. Just remember you will be paying for rebuilding the turbo and the engine on a more frequent basis.

I really hate tubos on street cars. They are designed for racing at very high rpms. This is not a cheap way to go.

But good luck, and I wish you well. Keep your dollars totalled up. When you go past 1500 dollars, realize a 5 speed 302 would now be running 12.50's. Where are you now?????

Jim, I know it sounds like I'm picking on you, but let me try an provide my answers to some of your replys.

Replacing hoses ever 25-50 k miles. Where did you get your information, just curious? What kind of person would spend the time and money to build any kind of high performance motor, whether it be NA, blower, nitrous, or turbo and then not mind replacing a few hoses ever so often. Seems like a cheap price to pay for the amount of hp and torque a turbo will provide.

And who builds the above mentioned type of motor and then uses cheap oil. Come on now, we know better.

A cheap turbo timer maintains oil circulation once the engine is turned off. Vortech or Paxton blowers both run oil through them, does the same "coking" not happen with them as well?

As far as the 15 psi comment, let me throw this combination out there to you. Trick Fow intake & heads, stock cam, bigger fuel system, and a T-72, all backed with a tremec and 3.55 gears. What kind of numbers you think it makes and runs at the track? Try 494 rwhp and 536 ft/lbs or torque and a 10.82 at 129 mph. All on only 9 lbs of boost on a stock bottom end 302. It's also an ever day driver. V8s don't require the high amounts of boost that the GN and Supra 6s take to run fast.

And who doesn't rebuild a race motor once it hits 100 k miles, most do it before then.

I wil agree with you on the money and age thing though. If your on a budget, a turbo setup may not be the best thing for you.

And turbos are not for high rpm applications. Where do you think a GN shifts at, most barely over 5000 rpms. And I know of no one with a turbo on a mustang that shifts and higher than 6000 rpms. You just don't have to spin a turbo to high rpms to make power.

And with some of the right connections (i.e; someone that can weld and do some fabrication), you can build a JY setup for less than the above mentioned $1500.

Keep em coming, I like trying to dispell some of the myths about turbos .

[moc]

It's alot harder than it seems (and you'll find that out) But if this is what you want to do (study up ) and find every thing you can read on Turbo's and AKA Mustang's ,,Cause you are going to need that elective

[jim_howard_pdx]

Hey 91 GT Turbo,

I build speed.

I build supercharged, turbo charged, twin turbo, NOS, Rotary, OHV, SOHC, and DOHC. So I was directing my comments to the young man (same age as my son.) I mean no disrespect to you or to anyone that owns or loves turbo engines.

My comments were more directed to understanding the value of engineering, money, cost over time, damage to the engine bay, and costs of required maintenance and scheduled or unscheduled rebuilding.

Did anyone tell the kid that he could expect his turbo to run worse as it gets older, until it eventually runs worse than a stock honda? Did anyone mention to him the thousands of dollars it costs to do scheduled rebuilds of the engine, the turbos, the waste gates, and other associated parts.

Doesn't sound like a project I would jump at on a limited budget.

You run decent ET's on your turbo Mostly I like turbos because they are a blast as they spool up. They have exhilerating performance curves that really can only be experienced driving a turbo car.

I think you missed my point about coking a turbo. It is not a matter of "IF" the turbo cokes, it is "WHEN" the turbo cokes. You can feed a turbo engine two quarts of oil on shut down and it will still coke up in 40-100,000 miles. I don't think a 19 year old should put every dollar he has into a twin turbo and have nothing left for the 3,000 dollars it will cost to properly rebuild.

I would urge him to buy a great turbo car, and modify that in the simplist way possible to achieve the goal he has with the car. Now if his goal is to have the only twin turbo engine in town, then that is fine and I am happy to help any way I can.

Superchargers do not coke because the bearing and shaft stop with the crank case, and the bearing is heated only by rotational friction of the bearing, the friction of the charged air, and the friction caused by the impellers. They just don't get hot enough to coke up. Bearings wear out, but that is true with any rotational device.

On a turbo the temperature is generated by the exhaust and most Turbo impellers are over 900 degrees on shut down. So coking is a fact of life even with post shut down oil supply.

I love turbos at bonneville, on a track car, and even on hot rods. I really love the Grand Nationals. I have an acquaintance that runs 10.90s in Spokane Washington on his superb set up.

Lots of fun.

My buddies Turbo Porsche in LA was 65,000 new, then he spent 70,000 tricking it out. Did a top speed of 194. Quartered in 10.2 seconds. Did the 1/2 mile at 178 mph. It was set up as a canyon racer and he was never beat while I was there..... 3.6 liters of go and 24 miles per gallon on the street, 28 mpg on the highway.

LOTS OF FUN.

So I have lots of respect for turbos, and if the kid wants turbos the kid should build a turbo. I hope it is everything he wants it to be, and I hope everyone acknowledges him for putting in the effort to build such a cool ride. And I am happy to help in any way he can.

The title of his post was "is this overkill." I think it is on his budget. I think it is something he should research, study, and talk about with guys running turbos that share the good, the bad, and the ugly.

First he needs to define the purpose. Then he should improve the brakes and suspension, then he should rebuild the engine, and last he should button up the turbos and intercoolers. When you do it right, FUN WILL HAPPEN.

I think every car should have a purpose. That it be engineered to run safely and properly. That it should be fun. And that it should KICK A S S. So it sounds like you and me are really on the same page. Don't take my "questioning" advice this young man to be derogatory to the turbo crowd.

We are driven by the need for speed, or we would drive a Yugo or SUV.

[demon666999]

Well the purpose of this car is just for fun. Its gonna be my weekend race car. I have a 93 Acura integra for my daily driver already, of which ive already but lil over 6000 in. Ive been pricing the cost of engine build up and its commin to near 7000 with a 800 dollar stang thats in decent condition. I have one turbo now and am about to pick up another in a few days. I'm leaning towards a 351 now. Cause of the strength issues, plus i can get one for 600. And i will be paying no labor for the build up cause i'm being helped by my friends dad whos been building engines for years.
Would anyone like to tell me some parts that wuld make this thing fast and last?
i was told the steal crank,rods,pistons are very necisary. Plus i can get good hookups on parts through the same guy.
Will prob go carbed to save money too.
Like i said its not that i dont have money, I make decent money and still live at home. I just cant see myself saving 2-3000 at once.

[jim_howard_pdx]

You need to be bluntly honest with yourself. Do you want it to be a driver or trailered? Is it going to spend time on the street? What percentage of time? Is it going to spend time on the highway? What percentage of time? Is it going to be quartered, autocrossed or both?

What top speed and elapsed speed do you need?

When you look at all these issues, a 351 W makes a great platform for a number of projects. The stock nodular iron crankshaft is good past 500 hp. When over 650 hp you should be livin in forged steel. Use extreme lightweight pistons and rods. Knife edge the crank until it balances DO NOT GO CRAZY. Button up the heads and mains with studs and a girdle. Use a windage tray and a crank scrapper.

Build the engine at 8/1 compression. That way you can add the hair dryers to it if you want the thrill. You can get 700 hp out of this fairly easily at 16 pounds of boost with a decent turbo cam. Gale Banks got 901 HP from a 302 Chevy with twin turbos at 30 psi boost.

Lots of the modern high lift low duration low overlap cams will work just fine until you add the turbos.

I would run 9/1 compression on iron heads and no turbo

I would run 10/1 compression on aluminum heads and no turbo

The 302 engines would give you more room to hang all the dryers and wastegates. So I expect someone to tell you a stroked 302 would be better than a 351. They are right on the size issue. I like the 351 main journals and crank dimensions much better. But that is my hang up.

I would wait two years and buy a used RSX for your daily driver. At 200 hp, you can pick up an additional 75 horsepower with an intake and deleting the cat. These are wicked rides. You will smile all the way!!!

[demon666999]

Well it would be cheaper for me to rebuild the 351 and have it not break on me than stroke a 302 and have it breas if i push 600. But this car is going to be quarter mile car and see the streets on the weekends prob thats it.

And for a honda i love my integra I beat almost all 6 cylinders and a few v8s(mostly 80s models though) And runs great for the miles.
193,000

[jim_howard_pdx]

My daily driver is a 95 Civic Coupe with 1.6 SOHC VTEC engine. Buzzes to 8,000 RPM which is flat out addicting.

42 miles per gallon at 60 mph 38 mpg at 80. 30 mpg around town. Quarters in 15.4 and 0-60 in 8 seconds with the 4.40 gears.

LOTS OF FUN. And it handles great too. At 2650 lbs it is a wonderfully balanced sports car.

The RSX is what I want for my next driver. I have been studying and 275 horsepower is easy. Expect over 300 with turbo or supercharger or NOS.

With its superior weight and superior numbers in parasitic horsepower loss, it would CREAM a modern 4.6 Cobra.

[srv1]

Jim, go here: http://www.toohighpsi.com/index.htm

Demon. you are going to need something to retart your timing under boost. also you are going to need a cage.

as for overkill? yeah i think so. why not a single turbo? check out the above link. if you insist on twin turbo, i would definetly get a stronger block or dont run so many PSI's.

Also Jim, when was the last time you seen a diesel rev up to 6 grand with a turbo? they are not for "high rpm" use. it is the design of the turbo is where(powerband) you can use it.

I do agree with Jim though, you have to decide what you are going to use this car for first, or you will be owning a money pit. read my link and check out the "bone yard" turbo set up. just gives you an idea of what you can do with a little money.

Turbo's are more efficient than S/C. the exception maybe with a roots type.

[demon666999]

Well read back i pretty much said what my goals are for the car. As for the single turbo, i would prob have to get a turbo better than a used t3 amd i happen to already have one and can get another for like $50. So it seems to be the best idea. And i figured with the 351 i wouldnt need to get a stronger block. I may be wrong of course.

[jim_howard_pdx]

If you decide to run a twin turbo, I would check both the Mustang and the Thunderbirds engine compartments and select the one that will make mounting the hair dryers and waste gates the easiest.

Are you planning on running fuel injection or carbs? If you run fuel injection you will need at least 36 lb injectors. The 24 lb thunderbird injectors will just slow you back down.

If you go with the 351, use a good iron head like the Dart Windsor Jr. It is already set up with stainless steel valves for about 700 dollars. Has the 1.97 and 1.60 valves. Angle mill the heads to reduce the wedge to about 54 cc's Take away alot of that gap. Then counter mill the intake manifold. Port the heads to a 1250 Felpro gasket size. Port match the intake too.

Use a dome piston, like 12.5 to 1 compression. Make sure the valve reliefs work for your cam or modify them accordingly. Then take a dye grinder and smooth down the dome so there are absolutely NO ridges, no angles, and no edges that can glow and cause predetonation. When you have the entire piston really smooth then sand it to a semi polish and measure the cc's. You should end up with a .060 to .080 quench area between the dome and the wedge, filling in as much of the wedge space as possible. You are after 10.5 to 1 compression.

Now if you run the dual turbos with the very tight quench area, you will not detonate, and you will be able to get about 125-135 horsepower per liter safely. If you leave the stupid wedge large then you will have to drop the compression to about 8.5 to 1 to eliminate detonation. I would prefer to have the very tight quench and run up the compression. This gives you more volumetric efficiency, and you will be rewarded with more mileage.

We did this on a stroked Cleveland engine in a Pantera. It ran 212 mph at Bonneville. The engine never hickupped or coughed or sputtered and it held its world record for 3 or 4 years.

Just get rid of the wedge, and get the quench going for you and not against you.

You can do the same with a 358 windsor. Use the stock crank, use eagle rods, and domed pistons modified as above. Get the compression to 10.5 to 1. Then add your turbo whenever you want a thrill.

The 358 windsor can be cammed to give you about 500 hp without having to change it when you add the turbo. Just use a very high lift, low duration and low overlap cam. Comp cams has some great ones.

Make sure to run the trick MSD ignition box with retard. When the boost kicks in, it automatically retards the spark. These are slicker than snot.

My Honda 1.8 liter engines with 10.5 compression get almost 300 horsepower with a single high volume hair dryer. I do not dual turbo them because of space issues. They never detonate, and do not require water injection. I do like to use it when I am drag racing.