High Boost (nasty t-a, phil99vette, pro stock john come in)
#1
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High Boost (nasty t-a, phil99vette, pro stock john come in)
i was doin some searching about boosted 347s and seen the few guys in the title mention that the were running like 30 lbs of boost or something like that and it was years ago...
how were you guys goin this with out 6 bolt heads ?
i am building a 347 and goin to run a TC76 on it for now i know i am goin to max the TC76 out before i get the car in the 9s so i will be upgrading turbos some time in the future to somethin in the 88mm range and would like to get in on the secrets of high boost on a 4bolt head
how were you guys goin this with out 6 bolt heads ?
i am building a 347 and goin to run a TC76 on it for now i know i am goin to max the TC76 out before i get the car in the 9s so i will be upgrading turbos some time in the future to somethin in the 88mm range and would like to get in on the secrets of high boost on a 4bolt head
#5
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I ran MLS head gaskets in both boosted setups that I had.
Build #1 was 317 heads, YSi supercharger. Went 9.40@143/5.99/115/1.35 on 18 lbs of boost. KP's setup was kinda of similar (but quicker).
Build #2 had Allpro heads and an 88mm turbo. Unknown boost for my 9.44@144 pass/1.35/325's, but went 10.008@139 on 16 lbs on a 1.5 on pump gas. I sold that turbo kit to a buddy and he went 8.8x with it, LS2 + patriot heads... He was around 22 psi on the best pass.
I'd say boost in the 17-22 range and high 8's not a big deal assuming the tune is there, but low 8's = pushing water for a lot of 4 bolt setups. I have a few friends who went low 8's without pushing water but I can only think of two of them.
Build #1 was 317 heads, YSi supercharger. Went 9.40@143/5.99/115/1.35 on 18 lbs of boost. KP's setup was kinda of similar (but quicker).
Build #2 had Allpro heads and an 88mm turbo. Unknown boost for my 9.44@144 pass/1.35/325's, but went 10.008@139 on 16 lbs on a 1.5 on pump gas. I sold that turbo kit to a buddy and he went 8.8x with it, LS2 + patriot heads... He was around 22 psi on the best pass.
I'd say boost in the 17-22 range and high 8's not a big deal assuming the tune is there, but low 8's = pushing water for a lot of 4 bolt setups. I have a few friends who went low 8's without pushing water but I can only think of two of them.
#7
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i was doin some searching about boosted 347s and seen the few guys in the title mention that the were running like 30 lbs of boost or something like that and it was years ago...
how were you guys goin this with out 6 bolt heads ?
i am building a 347 and goin to run a TC76 on it for now i know i am goin to max the TC76 out before i get the car in the 9s so i will be upgrading turbos some time in the future to somethin in the 88mm range and would like to get in on the secrets of high boost on a 4bolt head
how were you guys goin this with out 6 bolt heads ?
i am building a 347 and goin to run a TC76 on it for now i know i am goin to max the TC76 out before i get the car in the 9s so i will be upgrading turbos some time in the future to somethin in the 88mm range and would like to get in on the secrets of high boost on a 4bolt head
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#8
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Meeehhhh....there's only so much you can do (within reasonable cost) to get a 4bolt to work from what i've read:
1) Thick deck head
2) Excellent surfaces on both block and head
3) MLS gaskets if you don't o-ring..hell, Koehler ran o-ring and MLS still, so who knows, haha.
4) CORRECT torque on the head across the entire head.
Beyond that, it's all in the tune and the gas you're working with.
I'm certainly not "high boost", but with only 7.5lbs, we went 9.8@134 in a 3600lb car. That was on e85 making 640 on a eddy-current dyno.
1) Thick deck head
2) Excellent surfaces on both block and head
3) MLS gaskets if you don't o-ring..hell, Koehler ran o-ring and MLS still, so who knows, haha.
4) CORRECT torque on the head across the entire head.
Beyond that, it's all in the tune and the gas you're working with.
I'm certainly not "high boost", but with only 7.5lbs, we went 9.8@134 in a 3600lb car. That was on e85 making 640 on a eddy-current dyno.
#9
7 Second Club
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Meeehhhh....there's only so much you can do (within reasonable cost) to get a 4bolt to work from what i've read:
1) Thick deck head
2) Excellent surfaces on both block and head
3) MLS gaskets if you don't o-ring..hell, Koehler ran o-ring and MLS still, so who knows, haha.
4) CORRECT torque on the head across the entire head.
Beyond that, it's all in the tune and the gas you're working with.
I'm certainly not "high boost", but with only 7.5lbs, we went 9.8@134 in a 3600lb car. That was on e85 making 640 on a eddy-current dyno.
1) Thick deck head
2) Excellent surfaces on both block and head
3) MLS gaskets if you don't o-ring..hell, Koehler ran o-ring and MLS still, so who knows, haha.
4) CORRECT torque on the head across the entire head.
Beyond that, it's all in the tune and the gas you're working with.
I'm certainly not "high boost", but with only 7.5lbs, we went 9.8@134 in a 3600lb car. That was on e85 making 640 on a eddy-current dyno.
#11
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last time i had the car on the scale it was 3720.. i am hoping to keep it as far under 4000 with the turbo..
thanks for all the info guys i dont thing i will be ever seeing over 20lbs on the 347...
would really like to start a 6 bolt motor one day..
thanks for all the info guys i dont thing i will be ever seeing over 20lbs on the 347...
would really like to start a 6 bolt motor one day..
#12
i ran a 91mm to 21psi with mls gaskets and the block oringed. that was with stock casting l92 heads on e85, made 1000hp fairly easy.i always run mls and orings, copper tends to leak ive heard.
#15
It's not just the deck that moves around, it's the whole block. Same with the heads, the entire head flexes and lifts up allowing the gaskets to leak. The iron block will take a lot more than the alum obviously.
Here's what I learned from experience on my 4 bolt iron block/Allpro head combos:
5.3 block bored 3mm, 3.622 crank:
- GMPP MLS gaskets dry, ARP torqued to 75 ft lbs; dyno'd great, 1/8 mile great, first few 1/4 passes at 17-19 psi pushed ~8 ounces of water out each pass
- Cometic gaskets dry, same thing
- Cometic gaskets cut rivets out, Hylomar every layer, 75 ft lbs, a little better maybe 4 oz per pass
- retorque to 90 ft lbs; no more water pushing at ~20 psi running mid 8s at ~165 mph 3300#
6.0 block bored 0.030" filled to 1/4" above lower hole in block with block concrete, same 3.622 crank
- 5 layer GM gaskets, copper sprayed on only the outside, torqued to 90 ft lbs; no water pushing yet at over 20 psi running low 8s at ~172 mph
Here's what I learned from experience on my 4 bolt iron block/Allpro head combos:
5.3 block bored 3mm, 3.622 crank:
- GMPP MLS gaskets dry, ARP torqued to 75 ft lbs; dyno'd great, 1/8 mile great, first few 1/4 passes at 17-19 psi pushed ~8 ounces of water out each pass
- Cometic gaskets dry, same thing
- Cometic gaskets cut rivets out, Hylomar every layer, 75 ft lbs, a little better maybe 4 oz per pass
- retorque to 90 ft lbs; no more water pushing at ~20 psi running mid 8s at ~165 mph 3300#
6.0 block bored 0.030" filled to 1/4" above lower hole in block with block concrete, same 3.622 crank
- 5 layer GM gaskets, copper sprayed on only the outside, torqued to 90 ft lbs; no water pushing yet at over 20 psi running low 8s at ~172 mph
#17
8 Second Truck Club
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When you guys talk about o-ringing the block and using mls gaskets are yall cutting receiver grooves in the heads? Seems like the groove would have to be cut deeper into the block if not, or am I missing something? Is there a prefered thickness/material wire to use?
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well the car will be hopefully 3850 or so... i will keep it around that as much as possible....
i would like to see 9s on the 347 ls1 block at 9.3:1 compression at about 18-20 psi... really think i can get 9s and being that porky...on the tc76 anyway
thanks for all the info guys im new too the turbo thing i think its goin to be more fun then i am ready for
i would like to see 9s on the 347 ls1 block at 9.3:1 compression at about 18-20 psi... really think i can get 9s and being that porky...on the tc76 anyway
thanks for all the info guys im new too the turbo thing i think its goin to be more fun then i am ready for
#19
oring is stainless in the block, the head doesnt have a groove. I ran ls9s the past two times but will try ls3s next. the thin deck will barely get you too 1000rwhp with the stock decks.
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o ring and MLS here too , been running it for years on my iron block with the oring on the block and no reciver groove on the heads .
and make sure your tune is spot on !
and make sure your tune is spot on !