VHP heads
now. test parameters are changing. because of the right cat coming apart, i will be hollowing the hi-flow cats out and adding o2 simms. will go back to track for more runs before tuning. at least we can see how much more i can gain by 'removing' cats.
Last edited by mrr23; Jan 22, 2005 at 05:35 PM.
marc w - the 8 mph is a loss from the last time i was out. right side cat came apart internally. i have pics of it.
on the heads alone, i gained .2 and 2 mph with a bad cat (not apart but throwing code)and no tuning. cats are hollowed out now and o2 simms in place. going back wednesday for more times before tuning. i might try to play with the VHP tuner while i'm there.
on the heads alone, i gained .2 and 2 mph with a bad cat (not apart but throwing code)and no tuning. cats are hollowed out now and o2 simms in place. going back wednesday for more times before tuning. i might try to play with the VHP tuner while i'm there.
TECH Addict
Joined: Oct 2003
Posts: 2,620
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From: Central, MA
Awe geeze... The 8mph thing is a reading comprehension problem of mine. Even with the bright pink outlines - I still read the times off of the left lane on those Before/After - no juice runs... Sorry for the confusion there.
Either way, good stuff. That car's still on the stock cam, right?
Either way, good stuff. That car's still on the stock cam, right?
yep stock cam. vhp waits until last to put a cam in. unless the customer wants it. get the most power without sacrificing driveability and idle quality. the heads just finished up stage IV of the series. stage V is the cam.
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Verdad Gallardo ok results are in:
distance-----NA ----- N2O
60ft ------ 1.930 --- 1.881
330ft ----- 5.460 --- 5.005
1/8 ------- 8.286 --- 7.559
mph ------ 87.32 --- 95.58
1000ft --- 10.743 -- 9.786
1/4 ------ 12.822 -- 11.671
mph ----- 108.59 -- 119.60
in comparing it with the beginning runs before heads with cats to now 4.8 ported heads and no cats it's:
NA .322 and 2.92 mph
N2O .378 and 6.34 mph
i'm going to discount the mph gain on the bottle. i had issues with the right cat when i did the before heads n2o run. i got the SES light during that run. so it was the beginning of the end right there. i've done 117 mph in the past at OSW. still no tune. but, next on the list.
distance-----NA ----- N2O
60ft ------ 1.930 --- 1.881
330ft ----- 5.460 --- 5.005
1/8 ------- 8.286 --- 7.559
mph ------ 87.32 --- 95.58
1000ft --- 10.743 -- 9.786
1/4 ------ 12.822 -- 11.671
mph ----- 108.59 -- 119.60
in comparing it with the beginning runs before heads with cats to now 4.8 ported heads and no cats it's:
NA .322 and 2.92 mph
N2O .378 and 6.34 mph
i'm going to discount the mph gain on the bottle. i had issues with the right cat when i did the before heads n2o run. i got the SES light during that run. so it was the beginning of the end right there. i've done 117 mph in the past at OSW. still no tune. but, next on the list.
from the other thread
99 pontiac formula
automatic
stock converter
3.23 gears
stock ls1 intake
stock ls1 cam
VHP airlid
VHP air filter
VHP MAF ends
VHP/Crane 1.89 accelerated lift rocker kit
VHP/Crane dual valve springs
bassani 1 5/8" optimum length headers w/hi-flow catted y-pipe
borla catback
CHANGING
VHP ported 4.8L heads
no cats
mr gasket .042" head gasket
99 pontiac formula
automatic
stock converter
3.23 gears
stock ls1 intake
stock ls1 cam
VHP airlid
VHP air filter
VHP MAF ends
VHP/Crane 1.89 accelerated lift rocker kit
VHP/Crane dual valve springs
bassani 1 5/8" optimum length headers w/hi-flow catted y-pipe
borla catback
CHANGING
VHP ported 4.8L heads
no cats
mr gasket .042" head gasket
Last edited by mrr23; Feb 15, 2005 at 07:02 PM.
Originally Posted by jrp
rest of the mod list? its confusing following all the different **** you do and what mods are on what car, lol.
this was just and R&D type of thing right?
this was just and R&D type of thing right?
today vinci added my flow chart to their page. he's considering selling them as 'street' heads. but like i said before, i test every little part i put on my cars. i like to know what that part does all by itself. unfortunately, the cat decided to interfere with the proceedings. i don't do a heads and cam and wonder which one did what.
Originally Posted by jrp
not bad. now throw a cam in that bitch 
Originally Posted by mrr23
that's funny. i was just typing the mods list when you posted this. R&D meaning that VHP only ported the 4.8L just for me? or i'm just trying to continue my PRODUCT PIMPNESS? today vinci added my flow chart to their page. he's considering selling them as 'street' heads. but like i said before, i test every little part i put on my cars. i like to know what that part does all by itself. unfortunately, the cat decided to interfere with the proceedings. i don't do a heads and cam and wonder which one did what.
today vinci added my flow chart to their page. he's considering selling them as 'street' heads. but like i said before, i test every little part i put on my cars. i like to know what that part does all by itself. unfortunately, the cat decided to interfere with the proceedings. i don't do a heads and cam and wonder which one did what.despite as much VHP pimping you do, the tests and results are always very interesting, keep it up
yes it was just for R&D purposes. car already has headers and now technically an ORY-. unfortunately for the wife, it's now too loud for her. i might be putting the bassani tru-dual on her car to quiet it down. now that'd be a neat test. borla w/small open plate vs bassani tru-dual. another thing i've seen wanted on this board. a single to dual test. HMMMMMMM
ok finally go it back on the dyno. first one is heads, no cats, untuned. second is untuned vs tuned using the VHP handheld tuner. as the notes say, i ended up using CAM #3 +10% power enrichment so, a total of 34 rwhp and 29 rwtq peaks.
