LB7 Turbo Advice

[K1SSRSS]

Hey guys, I finished up my injector install and have been driving my truck for about 3 months to make sure everything is in good order.

Now that it seems good, I am thinking about upgrades, I was going to order a cold air intake but after some research thought I should decide on my turbo first.

What are the best options out there, I do pull quite a bit so my goal is to keep the truck reliable, but it would be awesome if I could pull my race car to the track, unhook my tow vehicle and run 12's in it too.

I have stock injectors and won't be changing those anytime soon since they are new, I currently have the BD exhaust manifold and AD lift pump and my built tranny is in the works. I plan on some HSP intercooler pipes and CAI also.

What do you all recommend, an upgraded IHI, stepping up to something like an S366, or other options... I do have a T4 pedestal laying around, but the ease of dropping in an upgraded IHI is intriguing. Ultimately a second turbo on top of the IHI would be nice, but I think cost is too much of a factor at the moment.

Thanks for the help.

 

[fastpunker]

You are in the same boat I am or was about a year ago.... you are right on track with the mods and adding the built trans. My recommendation would be to just upgrade the IHI turbo with a batmo wheel or something of the sorts. This would keep you in the safe(ish) range of lifting the heads/stretching head studs/ and blowing the head gaskets. Most of my friends that have gone with a bigger turbo have lifted the heads stock stud lb7/lly trucks...

I am in the process of ordering a batmo wheel myself and down pipe. I currently run 12.7 with everything stock (or same mods as you are on track for) and added a normal air compressor regulator to the waste gate to get more psi out of the turbo... I set the regulator to hit 30 psi in 5th gear as I'm going down the track. This all depends on how healthy your cp3 is also... mine is really healthy so I am able to hold good rail pressure. I tow with mine with this set up all the time... with a different tune obviously though.

This is just my opinion and experience though... food for thought

 

[melms23]

S475 over stock would tow nice, easily do 12's and make good power with stock injectors.

Also no need to buy an intake or pull the factory turbo.

 

[K1SSRSS]

Awesome, thanks for the input guys.

 

[Chevy1925]

You are in the same boat I am or was about a year ago.... you are right on track with the mods and adding the built trans. My recommendation would be to just upgrade the IHI turbo with a batmo wheel or something of the sorts. This would keep you in the safe(ish) range of lifting the heads/stretching head studs/ and blowing the head gaskets. Most of my friends that have gone with a bigger turbo have lifted the heads stock stud lb7/lly trucks...

I am in the process of ordering a batmo wheel myself and down pipe. I currently run 12.7 with everything stock (or same mods as you are on track for) and added a normal air compressor regulator to the waste gate to get more psi out of the turbo... I set the regulator to hit 30 psi in 5th gear as I'm going down the track. This all depends on how healthy your cp3 is also... mine is really healthy so I am able to hold good rail pressure. I tow with mine with this set up all the time... with a different tune obviously though.

This is just my opinion and experience though... food for thought

No jonny boy... lol. The ones that blow a headgasket are the ones trying to drive a stock charger well beyond what it can handle, pushing drive pressure through the roof. Not to metion running quite a bit of timing to get that last bit of power, increasing cylinder pressures, thus increasing the chance of lifting heads. combine those two and its a ticking time bomb. BUT you dont see that much anymore as guys are much smarter with tuning and are not running the fuel to a stock charger to over drive the heck out of it.

the ones that blow a HG are generally on the old style LLY HG or have hurt them at some point and the added power found the weak spot. If you tune it and put a turbo on it that cleans up your fuel, rods are the weakest point so tuning again plays a roll.

Im with melms though. s475 over stock and either have the tuner keep torque under 1100-1200ft lbs higher race tunes or stay off them. a few runs under full boost and low rpm's will bend rods in a heart beat.... i know first hand . You will hit 12s even on a semi weak CP3 though. if my big boat could hit a 13.04 with just twins, built trans, lift pump and tuning, a stock truck is 12s no issue.

 

[yellowchevy]

X3 on twins if you're going to doing much towing. You'll have good power for towing, daily driving, & going down the track.

I personally would stray away from a 366 if you're going to tow much; I think you'd be much happier with a twins or a modified IHI. This is assuming you're wanting more than 550-600hp & plan on building the motor one day.
If you're just wanting a little more "fastpunker" is correct on just dropping in a batmowheel. Good drive ability and a little quicker spooling. The wetzel wheel is a good option as well but its not quite as good.

If you're not planning on building your motor then I would lean towards a modified IHI. I've gotten quicker spool up, lower EGT's, and more power/torque. Here's a link to testing I did on the different comp wheels and my porting/polishing on the IHI's if you're interested IHI Show Down.

Now the ultimate setup I feel would be a modified/ported/polished IHI in the valley with a 475 or 480 over top of it like James has. That way you'd get the best of both worlds!!:woott::thumb:

Yellowchevy

 

[fastpunker]

No jonny boy... lol. The ones that blow a headgasket are the ones trying to drive a stock charger well beyond what it can handle, pushing drive pressure through the roof. Not to metion running quite a bit of timing to get that last bit of power, increasing cylinder pressures, thus increasing the chance of lifting heads. combine those two and its a ticking time bomb. BUT you dont see that much anymore as guys are much smarter with tuning and are not running the fuel to a stock charger to over drive the heck out of it.

the ones that blow a HG are generally on the old style LLY HG or have hurt them at some point and the added power found the weak spot. If you tune it and put a turbo on it that cleans up your fuel, rods are the weakest point so tuning again plays a roll.

Im with melms though. s475 over stock and either have the tuner keep torque under 1100-1200ft lbs higher race tunes or stay off them. a few runs under full boost and low rpm's will bend rods in a heart beat.... i know first hand . You will hit 12s even on a semi weak CP3 though. if my big boat could hit a 13.04 with just twins, built trans, lift pump and tuning, a stock truck is 12s no issue.

I stand corrected haha. I forgot about the drive pressure side of it... I never claimed to be a know it all lol

 

[yellowchevy]

I stand corrected haha. I forgot about the drive pressure side of it... I never claimed to be a know it all lol

Hey hey hey, don't give James to much credit. It will just go to his head!!!:thumb:

On a side note I forgot to point out. I've got my wastegate set to 35psi and my back pressure has been at its highest 58psi when on the dyno. For daily driving, towing, and just having fun its stays right around 1:1; boost to back pressure.

Yellowchevy

 

[Chevy1925]

I stand corrected haha. I forgot about the drive pressure side of it... I never claimed to be a know it all lol

i thought engunmanears did know it all though :hug:

Hey hey hey, don't give James to much credit. It will just go to his head!!!:thumb:

Hey suck it Russ! :roflmao:

 

[fastpunker]

Hey hey hey, don't give James to much credit. It will just go to his head!!!:thumb:

On a side note I forgot to point out. I've got my wastegate set to 35psi and my back pressure has been at its highest 58psi when on the dyno. For daily driving, towing, and just having fun its stays right around 1:1; boost to back pressure.

Yellowchevy

I'll have to keep the James credit in check :roflmao:


I like the sounds of the 1:1 ratio... but you're not giving me all the facts here, making my head hurt lol. At what boost psi does the drive psi start to spike? come on, I want to see data and graphs here... chop chop!!

 

[yellowchevy]

I'll have to keep the James credit in check :roflmao:

I like the sounds of the 1:1 ratio... but you're not giving me all the facts here, making my head hurt lol. At what boost psi does the drive psi start to spike? come on, I want to see data and graphs here... chop chop!!

You best do that!!!:thumb:

My spread sheet is on the IHI showdown thread I posted & linked as well; I don't have a graph but I've got my peak numbers.
On the dyno my boost and back pressure would climb about the same till boost reached about 30psi, at which point it would climber a little faster than boost. It then kept climbing till it reached 58psi where as boost stayed at 33-35psi.

Yellowchevy

 

[fastpunker]

My spread sheet is on the IHI showdown thread I posted & linked as well; I don't have a graph but I've got my peak numbers.
On the dyno my boost and back pressure would climb about the same till boost reached about 30psi, at which point it would climber a little faster than boost. It then kept climbing till it reached 58psi where as boost stayed at 33-35psi.

Yellowchevy

Good stuff!! :woott: I'll have to look at the showdown thread again when I get home, dumb work computer won't let me see the pics in that thread..

 

[K1SSRSS]

Thank you guys for all the info, I am gonna read through the IHI info now. Ultimately my plans are to run the truck with the stock motor (not planning on studs either since I'd rather not tear into it that far) for about 2 years as I slowly build my spare motor. In that time, I'd be plenty happy with 500-600hp if it is reliable.

Ultimately I'd like to be around 800hp once the built motor goes in, and ideally for ease on the budget I'd like to choose parts that can be used both now and later.

 

[yellowchevy]

Thank you guys for all the info, I am gonna read through the IHI info now. Ultimately my plans are to run the truck with the stock motor (not planning on studs either since I'd rather not tear into it that far) for about 2 years as I slowly build my spare motor. In that time, I'd be plenty happy with 500-600hp if it is reliable.

Ultimately I'd like to be around 800hp once the built motor goes in, and ideally for ease on the budget I'd like to choose parts that can be used both now and later.

If thats your end goal I'd lean towards twins. Good power now with a stock motor but room to grow. And if you still plan on towing its nice.

Yellowchevy

 

[Chevy1925]

Thank you guys for all the info, I am gonna read through the IHI info now. Ultimately my plans are to run the truck with the stock motor (not planning on studs either since I'd rather not tear into it that far) for about 2 years as I slowly build my spare motor. In that time, I'd be plenty happy with 500-600hp if it is reliable.

Ultimately I'd like to be around 800hp once the built motor goes in, and ideally for ease on the budget I'd like to choose parts that can be used both now and later.

Put an s480 over the stock charger and then mod the stock charger via yellow Chevy and that turbo setup will be good for the 800hp you are after.

 

[Sledhead]

Put an s480 over the stock charger and then mod the stock charger via yellow Chevy and that turbo setup will be good for the 800hp you are after.

Pretty much what I'm thinking. With this set up whats the pros of S480 vs S475 (again please, I've been gone a while) And what options on the BW?

 

[Chevy1925]

480 moves quite a bit of air over the 475 at the expense of just a tad more lag. My 480 is box stock, no different covers or anything. The combo of the modded stock charger and the 480 was good for 60hp with a decent boost leak between the two chargers

 

[melms23]

Thank you guys for all the info, I am gonna read through the IHI info now. Ultimately my plans are to run the truck with the stock motor (not planning on studs either since I'd rather not tear into it that far) for about 2 years as I slowly build my spare motor. In that time, I'd be plenty happy with 500-600hp if it is reliable.

Ultimately I'd like to be around 800hp once the built motor goes in, and ideally for ease on the budget I'd like to choose parts that can be used both now and later.

Definitely go with the s480. I'm kicking myself for not doing it right away. If you have a spare motor you could always build your own twin kit.

If it was me, I would wait until you pull the motor to get the ihi worked over but I'm lazy.

 

[Sledhead]

480 moves quite a bit of air over the 475 at the expense of just a tad more lag. My 480 is box stock, no different covers or anything. The combo of the modded stock charger and the 480 was good for 60hp with a decent boost leak between the two chargers

It's the lag that I want to improve. Since the bigger I/C I've lost some response. Tuning will help but what is the least laggy IHI/S475 set up?

 

[Chevy1925]

Initial lag will be from the stock charger. Once you get it building boost, you feel the large one coming in. You don't notice it now cause the 475 come on quick.

Have you check really well for boost leaks?