7.3 2.5" power potential

JD3020 · Mar 17, 2014

I know that 2.5 class set-ups have been discussed on here a couple times, but has anybody actually put together a truck and ran it? I have yet to see or hear about any 7.3's running a 2.5 turbo, but i'm curious as to how these engines do with a stock or billet 463. I've heard numbers from the Dodge and GM guys that range from 6-900rwhp with em, but never anything from the Ford camp.

I'm working on a "build" right now that will involve big oil, 250/200%'s, S400 with a 92mm turbine wheel, and to get it going a cast 63mm wheel/cover. Is 400hp possible with a cast 63mm wheel? I'd like to be around 600hp eventually so i'll step up the injectors and turbo, but even then is 600hp possible? Just looking for some input as i've had this discussion with a couple different guys but nobody really knows what's been done or what is possible

lincolnlocker · Mar 17, 2014

JD3020 said:
I know that 2.5 class set-ups have been discussed on here a couple times, but has anybody actually put together a truck and ran it? I have yet to see or hear about any 7.3's running a 2.5 turbo, but i'm curious as to how these engines do with a stock or billet 463. I've heard numbers from the Dodge and GM guys that range from 6-900rwhp with em, but never anything from the Ford camp.

I'm working on a "build" right now that will involve big oil, 250/200%'s, S400 with a 92mm turbine wheel, and to get it going a cast 63mm wheel/cover. Is 400hp possible with a cast 63mm wheel? I'd like to be around 600hp eventually so i'll step up the injectors and turbo, but even then is 600hp possible? Just looking for some input as i've had this discussion with a couple different guys but nobody really knows what's been done or what is possible

With those dimensions being not much bigger then a stock turbo I dont know how much improvement it would be... but then again it might be just enough to make some difference.

live life full throttle

1badpsd · Mar 17, 2014

I think it could make a little power, I know its different turbos, but I built a friends truck with 250/200,s468 and an old TE modded 17*(he has had pump) and he did 551 @40 psi with a plenum leaking and was dropping icp past 2500rpm.

Groomzybanshee · Mar 17, 2014

A lot depends on the turbo rules.. Tru bore 2.5 stepped /clipped wheel?

JD3020 · Mar 17, 2014

lincolnlocker said:
With those dimensions being not much bigger then a stock turbo I dont know how much improvement it would be... but then again it might be just enough to make some difference.

live life full throttle

Disclaimer:I know very little about turbo's so somebody correct me if i'm wrong.

But theres a lot more to it than just the inducer size. For example a stock compressor wheel is roughly 58x80mm, whereas a S463 wheel is 63x92mm. You also have a larger turbine wheel/housing, like in my case 92mm vs whatever tiny wheel a GT38 has. I imagine the billet 2.5 wheels have a much larger compressor exducer.

And around here 2.5 is a protrusion class.

Turbocharger:

S-4, GT 42, HX 50 and turbo of this type is the largest turbo allowed. T-4 mounting flange is the largest allowed. No clipped wheels or step down covers. Billet compressor wheels are allowed. A single .200 inch MWE groove maximum allowed. Inducer bore must be non-removable. All air must go through the 2.5 inducer bore and MWE groove. The wheel must protrude into the 2.5 bore 1/8 inch. Turbo checked with a 2.550 plug.

lincolnlocker · Mar 17, 2014

JD3020 said:
Disclaimer:I know very little about turbo's so somebody correct me if i'm wrong.

But theres a lot more to it than just the inducer size. For example a stock compressor wheel is roughly 58x80mm, whereas a S463 wheel is 63x92mm. You also have a larger turbine wheel/housing, like in my case 92mm vs whatever tiny wheel a GT38 has. I imagine the billet 2.5 wheels have a much larger compressor exducer.

And around here 2.5 is a protrusion class.

You are correct that there are a lot more to turbos then inducer but
Hmmmm.... why was I thinking a stock turbo inducer was a 60 or 62mm....

live life full throttle

JD3020 · Mar 17, 2014

lincolnlocker said:
You are correct that there are a lot more to turbos then inducer but
Hmmmm.... why was I thinking a stock turbo inducer was a 60 or 62mm....

live life full throttle

Because you would be correct. LOL Just googled it and the stock wheel is 60mm inducer. I'll have to dig out my tore down stock turbo and get some measurements as i'm curious as to how small the stock turbine wheel is.

lincolnlocker · Mar 17, 2014

JD3020 said:
Because you would be correct. LOL Just googled it and the stock wheel is 60mm inducer. I'll have to dig out my tore down stock turbo and get some measurements as i'm curious as to how small the stock turbine wheel is.

80ish I think

68/76 from what I found.
live life full throttle

4.0l sahara · Mar 17, 2014

I wouldn't waste my time on a 7.3 in 2.5 just my opinion tho. I just don't see it ever being competitive.

NyCowboy87 · Mar 18, 2014

If you want to pull in a limited inducer class you need to focus on moving the available air as efficiently as possible. A nice cam, head porting, headers and a free flowing intake manifold. Many people are also playing with raised compression ratios for the limited inducer classes and say it helps. Just some food for thought it's not always about what charger you are running, more importantly it's the whole setup.

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powerstrokenstang · Mar 18, 2014

If its protrusion clip a s475. But like said its the whole package. And if you can run clipped wheels its not much diff than 2.6. Even back in the day a 62mm h2e would support 500hp with a 200% nozzle. I ran 8.05 in the 1/8 with that setup on a bone stock long block.

JD3020 · Mar 18, 2014

4.0l sahara said:
I wouldn't waste my time on a 7.3 in 2.5 just my opinion tho. I just don't see it ever being competitive.

I doubt a 7.3 will ever be top dog, but i don't see why a well set-up 7.3 couldn't be halfway competitive. The main reason i'm going with a 7.3 is i'm getting tired of going to pulls and it only being GM's and Dodges. Not really interesting to watch when everything looks, sounds, and runs exactly the same. I will say there was one pull last summer when my truck actually did halfway decent and my POS turned some heads. Plus i think i can have this truck on the track with all my mods and some suspension work and have less than $4k in it including purchase price, and i'd guess it'd weigh in around 5800 so i can hang plenty of weight.

I'd like a cam but i'm going to be running my old engine, so i'd have to go with something that doesn't require reliefs and IDK if i'd gain anything. I have thought about making headers of some sort as my current manifolds are rusted out.

Petro · Mar 18, 2014

JD3020 said:
I doubt a 7.3 will ever be top dog, but i don't see why a well set-up 7.3 couldn't be halfway competitive. The main reason i'm going with a 7.3 is i'm getting tired of going to pulls and it only being GM's and Dodges. Not really interesting to watch when everything looks, sounds, and runs exactly the same. I will say there was one pull last summer when my truck actually did halfway decent and my POS turned some heads. Plus i think i can have this truck on the track with all my mods and some suspension work and have less than $4k in it including purchase price, and i'd guess it'd weigh in around 5800 so i can hang plenty of weight.

I'd like a cam but i'm going to be running my old engine, so i'd have to go with something that doesn't require reliefs and IDK if i'd gain anything. I have thought about making headers of some sort as my current manifolds are rusted out.

This is also the problem we have around here, all Gm and Dodge. Last year my wealthy friend gave me the go ahead to build a 7.3 that would somewhat compete in the 2.6 class at the local county fairs. The setup I put together competed quite well , the limiting factor was traction. It just didn't hook up real great, needs a lot of suspention work. Truck was a 02 F350 ccsb, Forged Rods, built auto, 275/200 stroked A codes, S475, Srp 1.1, water/meth and full fuel system. It may have seen some spray also but we kept that quiet lol. Now I'm sure competition is a little tougher in your area but I think with the right suspension you should have no problem being halfway competitive, at least put on a show.

lincolnlocker · Mar 18, 2014

Petro said:
This is also the problem we have around here, all Gm and Dodge. Last year my wealthy friend gave me the go ahead to build a 7.3 that would somewhat compete in the 2.6 class at the local county fairs. The setup I put together competed quite well , the limiting factor was traction. It just didn't hook up real great, needs a lot of suspention work. Truck was a 02 F350 ccsb, Forged Rods, built auto, 275/200 stroked A codes, S475, Srp 1.1, water/meth and full fuel system. It may have seen some spray also but we kept that quiet lol. Now I'm sure competition is a little tougher in your area but I think with the right suspension you should have no problem being halfway competitive, at least put on a show.

What tires did you guys try?

live life full throttle

Petro · Mar 18, 2014

lincolnlocker said:
What tires did you guys try?

live life full throttle

Mickey Thompson MTZ's. I think the best part about the whole experience was having guys from both the GM and Dodge crowd come as tell us how impressed they were with how well the truck ran. Since there are almost ZERO Modified Fords pulling in this area, it surprised a lot of people, and it got second's and thirds in several pulls.

Petro · Mar 18, 2014

http://powerstrokearmy.com/photopost/data/500/medium/1004835_10151854838613974_45300355_n-1.jpg

Here's a pic of it pulling in the light class. I'll quit derailing this thread and let it get back to technical talk. I think I somewhat made my point that a 7.3 can compete to a certain point, you just won't be top dog. But it is fun being different.

lincolnlocker · Mar 19, 2014

Petro said:
http://powerstrokearmy.com/photopost/data/500/medium/1004835_10151854838613974_45300355_n-1.jpg

Here's a pic of it pulling in the light class. I'll quit derailing this thread and let it get back to technical talk. I think I somewhat made my point that a 7.3 can compete to a certain point, you just won't be top dog. But it is fun being different.

Track looks hard and dry. Is that the type of track you normally pull on?

live life full throttle

Petro · Mar 19, 2014

lincolnlocker said:
Track looks hard and dry. Is that the type of track you normally pull on?

live life full throttle

Ya most of the tracks we pulled this year were harder than f uck and very dry.

Oil Field Trash · Mar 19, 2014

Petro said:
Ya most of the tracks we pulled this year were harder than f uck and very dry.

Some Truxsus sts would have worked better than MTZ's on a hard pack.

Sent while I probably should be doing something productive.

Petro · Mar 19, 2014

Oil Field Trash said:
Some Truxsus sts would have worked better than MTZ's on a hard pack.

Sent while I probably should be doing something productive.

It was a learning experience. If it pulls this year it will be getting 400/400s and twin pumps and probably a built bottom end. Time will tell. Learning as we go.