Building 7.3 idi

[doofussevilla]

Truck started off as a 7.3 idi with 088 turbo and zf5 trans pushing 3.55 gears. i'm young and wanna go fast so i got my hands on a factory turbo and slapped it on her. I was running about 15psi daily on my commute to work, ******* 18-19 psi floored. I still wasn't happy with egt's and power so last month i installed my psd inter cooler. it was making decent power after that, egts still were on hot side, needed to time it. however i blew the head gaskets after flooring it from a zero to sixty instead of easing into it. The engine was tired so it got torn apart, machined .020 over, crank cut .010 under. I ordered studs, and cam from r and d last night. what turbo can keep egts cool with like 150cc???? s366 using 093 hotside? posting this to get educated, educated others, and showing off my build step by step. I'm not any crazy mechanic by any means. just your average teenger looking for some extra power.

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------before intercooler, egts were still pretty high..

 

[Thewespaul]

Okay buddy let me help you out here,

First, are you sleeving the block as well or just trying to increase displacement? The cylinder walls of the 7.3s are known to be very thin and already have cavitation issues and if you make that wall thinner you will only weaken the block even more.

Next if you are trying to lower your egts you need to have your timing set properly with a timing meter, not by ear or by a shop that doesnt know what they are doing. The 093 hotside is too small already so you will need a larger hot side as well, talk to justin over the phone at R&D about sizing a turbo for your needs, he supplies his own.

You need to know that these engines are not power monsters and they take work and knowledge to get them up to the level of modern trucks, the egt limit on them is 1200 degrees, any more and you will melt pistons and exhaust valves and on stock head bolts you shouldnt go over 15lbs. There is a wealth of information on this forum and if you read up in the tech forums and use the search function you will answer a lot of your questions. Hope your build goes over well for you and good luck.

 

[Hydro-idi]

.020 over on a 7.3 idi has been done many times, but I would never trust it even if block showed no signs of cavitation. Just my opinion on that one tho.
Timing is very crucial on how these engines run & heat up. Sounds like your pushing the engine on what it can reliably handle. These engines will never be a psd & sometimes patience is better than pushing the limits of what these old dogs were designed for.
As for the turbos, R & D, Conestoga diesel & typ4 aka Russ can hook you up with what you'll need.
Also, get those heads checked out. If you've run excessive egt's for extended periods of time, they're likely cracked making them a damn good boat anchor. I've been there done that a couple times.

 

[pelky350]

I have a similar project going on, started with a 088 ats, then stage1's injectors, then 90cc pump r and d, 4 inch straight pipe, custom intake. Just installed factory turbo, banks downpipe and 60-1 cold wheel mod, it's alive now burns all the fuel a 90cc will throw at it, cx racing intercooler coming soon!

 

[88 Ford]

You will definitely need a bigger hot side than the factory hot side. It is too restrictive. While you are at it, use some Zerex Extended Life Coolant. My engine is also bored out slightly and the ELC coolant will help prevent cavitation in the future. With a 150cc pump, I think you would want anywhere between a S362 to an S366 turbo. It just depends where you want it to spool and where you want the power to come in at. Also torque your studs to 150ft-lbs. At that torque, you shouldn't blow a head gasket again. Also like was said, check the heads for cracks AND flatness as well too!!!

 

[pelky350]

If the 088 ats has a bigger exhaust wheel than a factory turbo and the same cold wheel, why does the factory turbo make more power?

 

[Thewespaul]

because wastegate

 

[Black dawg]

If the 088 ats has a bigger exhaust wheel than a factory turbo and the same cold wheel, why does the factory turbo make more power?

It doesn't make more power usually, just different power, being wastegated it makes decent boost early on...during the engines torque peak.

Keep upping the fuel on a factory kit or even the ats 093 kit and you will run into exhaust restrictions(if you are running it up to the governor), where the non gated kits are just starting to work really good. In my experience, the internal wastegate isn't big enough to control backpressure with high rpm and high fuel rate.

 

[doofussevilla]

Okay buddy let me help you out here,

First, are you sleeving the block as well or just trying to increase displacement? The cylinder walls of the 7.3s are known to be very thin and already have cavitation issues and if you make that wall thinner you will only weaken the block even more.

Next if you are trying to lower your egts you need to have your timing set properly with a timing meter, not by ear or by a shop that doesnt know what they are doing. The 093 hotside is too small already so you will need a larger hot side as well, talk to justin over the phone at R&D about sizing a turbo for your needs, he supplies his own.

You need to know that these engines are not power monsters and they take work and knowledge to get them up to the level of modern trucks, the egt limit on them is 1200 degrees, any more and you will melt pistons and exhaust valves and on stock head bolts you shouldnt go over 15lbs. There is a wealth of information on this forum and if you read up in the tech forums and use the search function you will answer a lot of your questions. Hope your build goes over well for you and good luck.

I think i'll be fine as long as i put the right coolant in. i already paid $1000 for machine work, no going back lol. i bought a mt480 but blew the heads before i could time it. ive hit 1300 for a few seconds, and ran it at 1100 for miles. I'm lead to believe if get the engine built for it, she'll run find with plenty of boost. i dont want to bother justin he seems busy, im sure there's others that have built idi's that can share info.

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[doofussevilla]

You will definitely need a bigger hot side than the factory hot side. It is too restrictive. While you are at it, use some Zerex Extended Life Coolant. My engine is also bored out slightly and the ELC coolant will help prevent cavitation in the future. With a 150cc pump, I think you would want anywhere between a S362 to an S366 turbo. It just depends where you want it to spool and where you want the power to come in at. Also torque your studs to 150ft-lbs. At that torque, you shouldn't blow a head gasket again. Also like was said, check the heads for cracks AND flatness as well too!!!

heads are at machine shop, resurface, magnaflux, resealed, 910 springs.

 

[doofussevilla]

Getting somewhere. Waiting on r and d cam, and head studs to get here. Is a s257 Borg Warner off eBay any good? Going with 90cc for now. Need truck back on road..

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[pelky350]

90cc has a good amount of fuel you won't be dis-appointed with it! Tons of fuel down low, you will receive a fuel chart of where your pump tested out at. Mine came with 108cc at 1000rpms and dropped to 96cc at 3000rpm. 90cc is just the minimum max fueling it will have at 3k Rpms.

 

[88 Ford]

Make sure it is a real S257. Verify part numbers if you can.

 

[Macrobb]

I *really* like a S360 with a .63 hot side. Yes, it's really tight, but it spools *extremely* well. Make sure you have studs when running this - I hit 30 PSI near instantly on acceleration with just a 110CC pump.
That should give you as much air as you want, and you can always add an external wastegate to the exhaust if it gives you *too* much pressure.

Bore wise, I had one bored .030 over. Worked, no cavitation issues. Ended up throwing a rod(machine shop not knowing what the F they were doing, valve clearance issues), but it *still* holds coolant.

Also, I always time by ear. I've found that what gives you the most power and sounds the quietest without giving any gray smoke on acceleration(black is OK) is generally best. This also results in lower EGTs.

You'll also probably find what I did - as long as you are not smoking, egts stay sane. It's when you start smoking out the tailpipe(overfueling/rich mixture) that they start creeping up.

 

[icanfixall]

Bet that test drive was on I60 thru the bad lands area. Driven it way too many times hauling horses. RV and dirt bikes. I was young once long ago.