he351 retrofit lag issues

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mtk454ss

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Nov 28, 2010
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Ok..i got my he351 installed on my 90 w250 and im having some boost and spooling issues. First off i did build a custom boost pipe from turbo to intake using 3 inch mandrel bends and eliminated grid heater while i was there..this is a non ic truck. Fuel screw is maxed and smoke screw is all the way down. My stock turbo would max at 37-38psi now with he351 im only getting about 40 with wastegate wired shut and wastegate solenoid hole in compressor cover welded closed ...i kinda assumed boost would be much higher??
Now the real issue happens in higher gears (4th and 5th)..1st thru 3rd spools fairly quick and will build about 30lbs and minimal smoke but when i grab 4th and 5th my truck is plauged with a lag that is as bad as my stock 18cm housed turbo if not worse!!!...boost is slow to come on and smoke is bad til around 30lbs and peaks at 40lbs.
Truck feels very sluggish and its baffling me...is my fuel settings too much and putting fire out in higher gears?? Intake piping too big or grid eliminate be a issue?? I really thought it would run better than this?
 
so no intercooler? what exhaust do you have after the turbo?
 
Sounds like boost leaks, exhaust leaks, or both. Post turbo exhaust leaks aren't a problem, pre turbo exhaust leaks are really bad for both spool up and power.

If I were you, I'd pressure test the boost charge pipe system with about 35 psi and find the leaks. Sometimes, the gasket under the intake plate blows out and it's hard to catch until you pressure up the whole setup.
 
no grid heater won't cause a problem at all. Your wastegate might be coming open a little. When I had my HE351 on and first installed it I had a bracket with a tight spring holding the wastegate shut, it would only get to about 10 lbs and open from drive pressure so i put a turnbuckle on it instead and tightened it right down then it was right up to 40 lbs and screamin. Something to check into cuz drive pressure can push that wastegate open a lot easier then ya think.

You could also check for boost leaks, with the engine running spray some ether around the intake gasket and boots, if the engine roars a little then you have a leak, if it idles normal and doesn't change when you spray then your good.

Mess with your afc tuning if nothing else to see what happens. Mine was different with my auto.
 
24vriviera said:
so no intercooler? what exhaust do you have after the turbo?
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Thats correct..no intercooler..just 3inch piping from turbo to intake. Exhaust is currently a 4 inch hood stack intil i get downpipe made.
No exhaust leaks either everything checks out..i will double check for boost leaks however..
 
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both holes in wastegate solenoid hole welded closed? and why aren't you running a wastegate actuator? 9cm is a tight housing, I bet on higher gears your, drive pressure is insane. that's a lot of exhaust to be running through that little of a hole without a gate
 
Well, update here!...i got her figured out! I did have small boost leak at the boot..( i found it by the small black streaks left by boost pushing past) ..that fix was worth 2 more lbs of boost! But the real discovery was my throttle linkage...when i eliminated grid heater and stock crossover i reluctantly forgot to make spacers to secure the giant throttle linkage plate at the top. This plate spans from the outer two crossover mount bolt holes down to the bottom of the block....so pretty much every time i stabbed the throttle the whole plate was pivoting rearward off of the one lower bolt holding it on..hence i wasn't getting full travel!
She is a damn rocket now...i peak 50psi in 5th and low end takeoff is very impressive... Im gonna have to figure out a wastegate for sure cuz the truck has over 520,000mi on the ticker!!!
My opinion of this turbo swap??... It has been totally worth it! I have only invested around 300 bucks for this swap with turbo costing me only a 100$ I encourage anybody on a budget to do this thank you fellas for all the help and ideas to figure this darn thing out!!
 
Let me know if you find another $100 He351. Heck, $150 is a steal, $200 is a good deal, and $250-$300 is the current going price.
 
Big Blue24 said:
Let me know if you find another $100 He351. Heck, $150 is a steal, $200 is a good deal, and $250-$300 is the current going price.
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X2!!! I loved mine on my 1st gen and wished I woulda never sold that turbo! Now I want another
 
Big Blue24 said:
Let me know if you find another $100 He351. Heck, $150 is a steal, $200 is a good deal, and $250-$300 is the current going price.
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To be truthful..i paid a kid 100 bucks for the he351 an hy35 and a ebay hx40!!! lol
 
does it sound anywhere close to as cool as the stock h1c? and what do you have to get to control the waste gate on one? and does the 9cm housing effect egts even though it is wastegated?
 
Took a spin in this truck last week, spools quick which delivers a nice wide power band. Quick enough toast the tires in front of my house in 1st, 2nd, and I think even 3rd with a Getrag.

mtk454ss is a turbo slut, someone needs to talk him into taking a picture of the, what, 15-20 turbos he's got lying around? Or better yet documentation of H1C vs HE351 vs HX52 vs HX40 vs HY35 spool up, boost, etc. He needs a magazine product tester contract lol.

-Dustin-
 
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06cumminspower said:
does it sound anywhere close to as cool as the stock h1c? and what do you have to get to control the waste gate on one? and does the 9cm housing effect egts even though it is wastegated?
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H1C will always have a sound of there own...Smokin Ace decscribed it once has having a screaming sound to it, and i agree with him!! The HE351 has a whistle to it at all rpms and whistles louder ,im guessing due to the tight exh. housing and bigger comp wheel and sounds different compared to the old h1c's. Also the sweet sound the h1cs made when lifting the pedal is gone now with the 351 :-(
Some are making custom brackets and mounting a traditional actuator to get boost control..i have been running my truck with wastegate shut for now.
I have know known difference in egt since i dont have my pyro hooked up yet but im curious to find out myself!!
 
Bersaglieri said:
Took a spin in this truck last week, spools quick which delivers a nice wide power band. Quick enough toast the tires in front of my house in 1st, 2nd, and I think even 3rd with a Getrag.

mtk454ss is a turbo slut, someone needs to talk him into taking a picture of the, what, 15-20 turbos he's got lying around? Or better yet documentation of H1C vs HE351 vs HX52 vs HX40 vs HY35 spool up, boost, etc. He needs a magazine product tester contract lol.

-Dustin-
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U watch Dustin, im gonna mount that hx52 on their someday..it will be my poormans silver bullet 66mm!! Hit 52lbs boost on her yesterday...twins what??:rockwoot:
 
Bersaglieri said:
Took a spin in this truck last week, spools quick which delivers a nice wide power band. Quick enough toast the tires in front of my house in 1st, 2nd, and I think even 3rd with a Getrag.

mtk454ss is a turbo slut, someone needs to talk him into taking a picture of the, what, 15-20 turbos he's got lying around? Or better yet documentation of H1C vs HE351 vs HX52 vs HX40 vs HY35 spool up, boost, etc. He needs a magazine product tester contract lol.

-Dustin-
Click to expand...

already done:pop:
turbo try outs - Competition Diesel.Com - Bringing The BEST Together
except hx35, 52 and 40
 
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