Which platform for 500whp?

[twin-turbos]

Originally posted by NosLaser
Personally, I'd start off with an F-body or perhaps a C4 Corvette for stability's sake. You could use an SN95 or Fox body stang, however I wouldn't take one much over 120, let alone the 250!!! PLUS speeds a Twin Turbo F-bod/C4 would be realistically and whole-heartedly capable of. I am going to spill the beans on the project I will have in the works shortly. I'm going to be building up a Twin Turbo 358ci V8. It will more than likely go into a '94 Firehawk I may be purchasing from a friend of mine.

A 358 is a good place to start because it has just about the most ideal rod/stroke ratio you can have. (It's the size they use for Nascar) A 358 is a 400 bock bored .060" over, with a small crank (out of a 283 or something along those lines) You can easily spend 10-12K on the motor alone. All the machine work on the block, a good set of heads with a small combustion chamber for a nice tight quench area. The ideal setup for a turbocharged car is to have a smallish combustion chamber, large valves, and dished pistons. Ideally, you don't want to go over 60cc's of combustion chamber volume. On a turbocharged application, you'll lose burn efficiency. You have a lot of cylinder pressure on a turbo car, this energy is ready to go off; it's so volatile, and the effect you are looking for is to get that energy as close to the spark plug as possible; you don't want it mushrooming out to the outer layers of the combustion chamber. When it does that, and it ignites out in the "outskirts" for lack of a better term, that is detonation. It's hard to explain on the internet, but basically, you want a dished piston to keep the air/fuel mixture in a nice tight ball of energy, and a smaller combustion chamber to keep it there. It is extremely important at this power level to cc all the combustion chambers so that they are the same volume. If you have differences in combustion chamber volume, it's like having differences in compression, and differences in burn efficiency. You also want the tops of the pistons and the combustion chambers to be as perfectly smooth as possible to avoid any hot spots. I would also possibly incorporate a dry-sump oiling system for ease of turbo placement.

You would need a custom intercooler, custom headers, and piping, and properly sized turbo's. I would say Twin 60-1's would make the HP level you seek. Obviously, you would need some suspension upgrades and a new Rear end; but they make rear end conversion kits to a Ford 9 inch for just under 2K for everything.

I would recommend using the SpeedPro engine management system now known as the FAST. Here's why. Since a turbocharged car is not rpm dependant, it is load dependant, you will need some form of map sensor which is the most accurate way of measuring manifold pressure. The MAS on a Corvette for instance is a hot wire setup. The way this works is there is a wire in the MAS that is set to stay at a certain temperature...let's figuratively say 200 degrees fahrenheit because I don't own a Vette and I'm really not sure exactly what the temperature is actually set at. If more air passes over that wire, it will take more energy to keep it at 200 degrees, and if less air passes over that wire, it will take less energy to keep it at 200 degrees. Based on how much energy must be exerted to keep that wire at that set temperature, the ECU adjusts accordingly for fuel. Would you really want to rely on that in a turbocharged vehicle?? This is why I recommend going with the FAST system. It has 4 things that are essential to a turbocharged vehicle. Number one, it has a map sensor which will again, provide your most accurate manifold pressure readings. Number 2, it has a wide band O2 sensor that will save your butt, Number 3, it has a knock sensor which is self explanatory, and number 4, it has a target air/fuel ratio table which coupled with the accuracy of a wideband O2 sensor, and the quickness of an adjustable knock sensor, allows you to keep on top of what's actually going on inside the motor. Let's say you go uphill or something, get on it, the turbo has more load on it due to weight (obviously) and let's say you experience a boost spike, or other phenomenon that causes a lean condition. This system will immediately detect that condition (because it is out of your 'target air/fuel ratio') and it will dump fuel.

Other than that, a good set of rods/pistons, good quality machine work and blueprinting, and you will have a motor that makes hella power, and stays reliable. Let me know if you need any more info.

Regards,

Ok, what you mention is true no doubt. The problems with a car designed to be an N/A are very true. What you want to do will cost a lot of money. It sounds like a great idea. Just too expensive for me. Let me ask you this, how much power will the stock LT-1 engine handle and how much torque can the rear end handle. If worse comes to worse and I can make 600RWHP on pump gas I will settle for an ATI supercharger
with my own fuel upgrades. I guess if I was to make this much power on the ATI I would have to boost to over 15psi's closer to 20psi's and get there racing supercharger as well as there most efficient intercooler. I believe with this kind of boost, compression and heads have to be addresses on the LT-1, correct??

Keep me up to date on your progress, it will sound like a killer, very interesting too, I just don't have the time(love it though) to fab headers and collectors and such.

 

[NosLaser]

If that's the case, I would buy a 98 (or other LS-1 powered F-body) and get NOS's new nitrous kit that plugs into your stock injector ports. LS-1's with even stock heads and intake make STUPID power with spray. 5.0 Magazine did an article on a BONE stock (down to the air filter) 2002 Mustang GT, with the 100 shot kit on that new nitrous system made 390HP and 520 torque to the wheels!! Nothing else!! On an LS-1 with the 175 shot jets, I don't see why it wouldn't make well into the 400's to the wheels, maybe 500, and prolly close to 700 torque. Just something to consider...

 

[twin-turbos]

Spray is cool. I am looking for the forced induction route! Though if I fall short of my goals spray will help me make the diff.

 

[rdrkt]

Originally posted by IPT
Lotus makes a nice v8 last time I knew... How about a Hennessy Viper?? V-10 baby!!

Lotus? Why would you want a crappy v-8? Hennessey is a crook you would be lucky if he even put your car back together after he was done stripping it.

Aslan since we are bench racing indulge me here. In a race from a roll I still think a Supra with 30k into it will do just as well as a 30k firebird. You seem to be building up a car very similar to Meany’s (sp?) car. But I think a Supra will be better suited and better geared for that application. If you take a look at Sw’s car he is till on a completely stock bottom end and I don’t think he has a ported head and he is making 850+ hp and I am sure most of his accleration is coming in the last 18th mile. I remember seeing a highway race not too long ago with a 396 supercharged lt1 vs Peter and SW. Sw walked away like the lt1 wasn’t even racing. Anyway if the project does materialize be sure to keep is informed.

 

[NosLaser]

...Aslan since we are bench racing indulge me here. In a race from a roll I still think a Supra with 30k into it will do just as well as a 30k firebird.....

I'm not bench racing, I'm simply offering ideas and knowledge on a buildup. More to that point, we aren't talking 30 grand vs. 30 grand, (although I'd take that bet in a heartbeat) we are talking all out power production here.

... You seem to be building up a car very similar to Meany’s (sp?) car. But I think a Supra will be better suited and better geared for that application.....

Meany's car is similar, but a car that existed much before that one was my initial inspiration, however that's an irrelevant detail to this conversation. The 6 speed T56 is geared to go over 300mph. What's wrong with that gearing? More to that point, the FASTEST stock body vehicle in the WORLD is a 94 Pontiac Formula, which ran 297 at Bonneville. Where is the Supra's advantage? The V8 has the advantage in weight, horsepower, torque, and if it doesn't have the advantage in gearing, it is at the very least equal to the Supra.

... If you take a look at Sw’s car he is till on a completely stock bottom end and I don’t think he has a ported head and he is making 850+ hp and I am sure most of his accleration is coming in the last 18th mile....

First off, SW's car has more money in it that you or I could fathom, and regardless of the B.S. being flung around by the Supra camp, that car is modified to all hell, and the head is very much ported. But, if we take this one step further, Meany's car would hand SW a beating he would never forget, but BADLY. Meany has at LEAST 10mph on him in the 1/4, and that defecit would continue to grow as speeds grew. You are talking 850hp vs. 1100 wheel HP.

... I remember seeing a highway race not too long ago with a 396 supercharged lt1 vs Peter and SW. Sw walked away like the lt1 wasn’t even racing. Anyway if the project does materialize be sure to keep is informed....

That particular Supercharged LT-1 wasn't making anywhere near 1000HP; it was making closer to 600 crank HP. The LT-1 motor, in the big scheme of things, sucks. I am talking about a custom built 358, be it with a junkyard 400 block, or a Dart crate block (depending on the power level and your budget) it will make more HP than ANY Import out there. Hands down. No argument. I'm not coming down on you or anything, so don't take this the wrong way (I hope it doesn't sound like I'm yelling at you.) Bottom line is anything a Supra can do, an F-body/Corvette/even a Mustang can do bigger/better/faster.

Regards,

 

[NosLaser]

Oh yeah, one more thing... I will find the link because DSM'ers are real big into PRRROOOOF. There is a school of automotive machinist that ran a stock bodied LS-1 Camaro to a 9.6 at almost 140 on motor. No turbo, no nitrous, no blower, just good ol' fashioned small block Chevy power. Build a similar quality motor designed to run boost, and your power potential is endless. There really isn't even an argument or comparison here. You could build a street-reliable Small block Chevy that would make too much power to be harnessed in ANY stock chassis car. My original plans called for Twin T-66's which would make somewhere in the 1500 wheel HP range, and trap in the neighborhood of 175+ but that is absolutely too much power (even for me ) for the sreet, so I stepped my plans down quite a bit. So I repeat, the V8 will do everything the Supra will do, but better.

 

[jdmawd]

So there's no chance the make the Talon run with a single turbo mkiv supra

i wouldn't say that for example Saturday at maple grove their was 1 singe turbo supra, the guy said it dynoed at 600rwhp but only ran 12.3 on radials with slicks and with a much better driver than that guy, its very capable of high 10.s to be honest that was the only supra in that trim that didn't run low 11's. on the highway forget about it at the track its all driver

Oh yeah, one more thing... I will find the link because DSM'ers are real big into PRRROOOOF

thats so very true sw's motor is about as stock as craig paisly's motor