twin turbo 331 ????
 

I'm gonna start building up a new motor in the next few weeks, It'll be probably a 331 with Turbo Driven Concepts Stage 2x twin turbo kit. I'm looking to get any advice and opinions I can get before I start buying. I'm looking to get around 600hp (thats on weekends with high boost, I won't be running full boost for daily driving), will a standard H.O. block hold up alright with a main stud girdle? Also, what are some good heads/intake setups. I was thinking about going with GT-40x or trick flow heads and a GT-40 or Cobra intake. I'm still not sure about the cam, I'll probably get a custom grind from Crane. Any info is appreciated.

On a 5.0 with gt-40 heads/intake(box stock) and 1.7rr's, they made 525rwhp & 591ft-lbs with 13psi & an incon twin turbo kit(the one that comes with everything), so it is completly possible.

I'm not going to say anything just sit here and drool. :p

That sounds like the type of setup i want in a few years
if i ever stop breaking and crashing my car i will get it

its about time we started to talk about Terrrbow charging! i hope you get it!!!

My best advice would be to ask the people who put the turbo kit together. They would probably know best what parts and mods will work the best for you.

Take care,
-Chris

Wow.....that thing is gonna RUUNNNNNNN.....hurry up and get it done....I want to see what times you get with it!!!! Just joking. Take your time, do everything right, and make sure you find a good combo for it. I don't know what to tell you about a twin turbo setup, not very knowledgeable in that subject....

Re: twin turbo 331 ????
 

First off to support that kind of hp with the stock block, even with the girdle, have it tuned by a professional or you'll be picking pieces up off the ground. With a 331 and twins 600 hp is easily reached. I'll give you an example of how much power a friend of mine made. He has the same kit as me except he has a 60-1 hifi instead of a T04, out of the box GT40 heads, GT40 intake, 30 lb injectors, 76 mm mass air, 70 mm tb, and a bigger fuel system. He made 411 rwhp with only 10 lbs of boost on pump gas through a hp robbing AOD. He's has and can run 20 lbs with race gas, although he's AOD didn't like the additioanl 10 lbs, if you get my meaning. I would feel safe in saying he would hit the 500 hp mark with the additional 10 lbs and race gas.

For your setup I would go with the trick flow heads or AFR 185's. For an intake I would lean toward a box style upper, I just don't think a GT40 and definately a Cobra will handle that kind of power. The stock cam and 1.7 rr are good for mid 10's, but since your spending the money for a 331 and twins, I would definately go with a custom cam.

Check out www.turbomustangs.com. We have links to all the turbo manufactures and as soon as the message board gets up and running, there are guys on there that know tons more than me.

Hope this helps.

I'd like to help, but I don't know anything about turbo's or superchargers. I'd like to know more too. I think I'll go and look at these sites,

What are some of the better box style upper intakes?

Cartech and Downs Ford each have box upper intakes.

whats the advantage of a box upper over a regular style upper?

Your gonna be able to rev higher(top end) with a box, from what I understand. I've considered getting a box for my car, though the Holley looks appealing..
Anything over 500hp on a stock block is risky business. A good tune, as 91GTturbo suggest, is a must. You can ask 100 guys if a stock block will hold over 500hp and 50 will say it will and 50 will show you pics of a split or busted up block.

The block, with a girdle, will be fine. It's the pistons I'd be worried about. The picture below shows a piston after I magnafluxed it. All 8 were like this, and he was running 8 (real) pounds of boost. I see it alot on boosted 5.0's. It's usually caused by bolting a blower on a stock bottom end, which is fine as long as you don't start cranking up the boost. Anyway, make sure you get yourself a good set of well fitted pistons.

Take care,
-Chris

http://homepage.mac.com/pkrwud/.Pict...%21/302.7.jpeg

I plan on replacing the entire rotating assembly with a Probe or D.S.S stroker kit (forged pistons,crank,I-beam rods,etc). I see a lot of people using 306s' also, but I figure if I'm already spending the money I might as well go bigger now with the 331. I've heard 347s' aren't too good as far as reliability/durability. I've also heard negative things about Probe (coast high performance) like them sending wrong cranks,etc., so I may go with D.S.S., their stroker kit goes for around $1200-1300.

Good stuff Chris. How much boost do you think the stock bottom end can handle? Or what do you recomend?

No more than 6 pounds. Keep in mind I mean a real 6 pounds, not the numbers the cheap boost gauges, like the turbo t-bird factory gauge, allow you to think you're reaching. Put it this way, above 6 pounds with stock pistons will require at least 95+ octane, and should run on 100. Past 6 pounds is the point where I won't do the work unless the customer follows my recomendations, which include new, lower compression blower designed forged aluminum pistons, and a tighter bore. I also insist on a better flowing fuel system, from the pump to the injectors, as well as a boost retard ignition box.

6 pounds of boost, at sea level, creates 430 cubic inches of displacement in a 302. If they want more than that, they're going to do it my way, or have someone else do it.

Take care,
-Chris

Do you think I should be alright @8 psi for daily driving and a little higher psi every once and a while on weekends with the stud girdle/forged pistons/race prepped crank/I-beam rods?

You'll be fine, provided the compression doesn't exceed 8:1. 8.5:1 is doable if you have 100 octane fuel available.

Take care,
-Chris

Apple Boy? or a baaaad seed?
 

hey Chris, what would be an accurate tool or gauge in measuring boost? i never hear much on the accuracy of gauges, so what do you know or recommend? i think most of us would like to know, smarty pants! j/k:D

Chris,

I don't nor am trying to start a flame war here, but with 8:1 he can run 10-12 lbs of boost on pump gas easily. I'm just adding heads to mine and I'm going to be running 8-10 lbs on pump gas with 9:1. Why do you say so low? With 8:1 unless he's making some big hp on motor, the thing want get out of it's own way.

The driver I worked for last season (2000) builds exotic race engines and tests them at his dyno and out at Willow Springs, and I've tagged along several times to learn what I could. What I learned from him regarding boost pretty much echoed what I was taught in my engines class at the local cc when I was preparing for my ASE Engine Repair and my ASE Engine Performance Certification exams, and that was that pump gas is not safe beyond 6 pounds of sustained boost in a stock small block Ford with 9:1 pistons. In fact, this is a widely accepted standard. There are different options available that can alter these numbers, but for a general guideline, 9:1 compression and pump gas can safely handle no more than 6 pounds of boost. That doesn't mean that you can't run more and not have a problem, it is only a recommendation of how much boost can be added without increasing the chances of detonation to an unacceptable level. For my customers, I will not install any combinations that will result in more than 6 pounds of boost if I know they have a stock bottom end with 9:1 or higher compression, without having them first sign a warranty release that becomes effective the first minute after they take possession of the vehicle. This hasn't caused a problem yet, as my customers trust my recommendations. I know I've got books around here that repeat what I'm saying, and if you like, when I have time, I'll dig through and find one or two for you if you would feel better about this by seeing it in writing.

I know that there are many people who regularly run 8-10 psi with 9:1 compression on pump gas, but they tend to be the ones that have the failures you hear about. I won't make a recommendation that has a high chance of failure. It doesn't help me and it doesn't help the customer, so why bother.

As far as an accurate method of measuring boost, the dyno was the best, but since it's difficult to carry one around in your trunk, a quality boost/vacuum gauge that is hardlined to an isolated manifold vacuum source is the best bet. Boost-only gauges, meaning those that do not also measure vacuum, are the worst, and almost always read higher boost than is actually being produced. The factory boost gauges are often off by 50% or more. Most forced air engines produce less boost than the owner thinks they do. I had a customer with a turbo T-Bird who claimed to have 10 pounds of boost "all the time". It actually never exceeded 5 psi, and even that was rare. He wasn't happy to hear that, and preferred the exagerated numbers, but then, he was that kind of guy. He liked exagerated HP numbers, too. ;)

Take care,
-Chris

Chris,

Are you talking non-intercooled or intercooled boost? I agree if someone trys to run more than 8 lbs on pump gas without the proper tune, problems can occur. Maybe not immediately, but overtime. But if the proper tune is applied, especially once compression is dropped below 9:1 and using intercooled boost, 10-12 lbs is easily attainable on pump gas without fear of problems.

I understand if this is something you do for customers, why you would try and be conservative, I probably would be too.

Thanks,
James

Non-intercooled. Like I said, there are alot of options that can change the recommendation, but with a stock set-up (9:1, 69cc heads, stock gaskets and bolts, and no intercooler), the fine line between safe and dangerous is 6psi on pump gas. Larger cc heads, o-ringed gaskets, ARP studs, heavy duty pistons, etc. all can contribute to higher safe boost levels, but it's still an octane game. If the pressure get's too high for the octane to control, the mixture will just start popping like pop corn.

Take care,
-Chris

Chris,

I assumed since the original topic delt with a turbo, we were talking intercooled boost. I don't think you ever specified in your posts that you were only talking non-intercooled boost. Now that we have that straight, I totally agree with you. If 429 builds a 331 with an intercooled turbo setup, he will easily be able to run 10 - 12 lbs on pump gas.

The twin turbo setup I'm going with from Turbo Driven Concepts is intercooled. As far as the rest of the motor, I'm thinking of going with AFR 185 heads, GT40 lower and Downs box upper, 331 stroker kit from D.S.S.(forged pistons,I-beam rods,race prepped crank)- I'm still not sure about the compression and camshaft, I'll probably go with a custom grind cam from Crane and keep the compression around 9-1, should I go with a smaller cam with 1.7 rockers or a little bigger with 1.6 rockers?

Dont get a stock Block If you are getting all the other good stuff **(I'm thinking of going with AFR 185 heads, GT40 lower and Downs box upper, 331 stroker kit from D.S.S.(forged pistons,I-beam rods,race prepped crank)- I'm still not sure about the compression and camshaft, I'll probably go with a custom grind cam from Crane and keep the compression around 9-1, should I go with a smaller cam with 1.7 rockers or a little bigger with 1.6 rockers?)
You want 600HP Get a new stronger Block and a EZ 700HP+ could be done With GOOD gas! I to Will be going to a Trubo When I get a New Short Block I Hope for Min of 600HP IF I do. I want alest 100% more Power over N/A And to get 600HP you will not have to come close to that Much with 100% more power that should make very Close to 400HP and a 50% incress right there will give you 600HP.

You should be a dignitary somewhere. No one has ever been so cordial with me when disagreeing.

Truthfully, I kept thinking he was talking about a blower, but the same rules apply. Yes, with an inter-cooler he will be able to sustain higher levels of boost, but I still don't see 12 pounds (sustained) on pump gas with 9:1 compression. Maybe, but I wouldn't recommend it. That's just me, though.

I have become a firm believer in lower compression for boosted engines. The lower your compression, the more boost you can safely achieve. Think about it... If you go with 8:1 and find some A/V gas, you could easily reach 15 pounds. At 15 pounds of boost, that 331 suddenly has over 670 cubic inches of displacement. That's what I like.

Make sure you get blower pistons. They're stronger, and are less likely to crack the skirts.

Take care,
-Chris