Some new results for my 455.
07-30-2011, 02:49 PM
#1
Some new results for my 455. My last set up ended up with some ring issues, while it was apart I made some changes. In the process it picked up 70hp.
What's in it.
REDs LS7 MID block. 4.198 bore.
Callies 4.125 Magnum crank
Compstar H Beam 6.125 rods
Wiseco pistons and ring package.
Morel lifters
PI 275 Cathedral port heads
Ported and modified Harrop 55mm intake
Kooks 1 7/8 headers
Cam 255 263 .67x lift 110
Big Stuff 3 to control it.
What did it do.
http://www.streetfire.net/video/ls7-...-2_2290861.htm
Thanks for the help and support from:
Wildgoose Performance
Erik Koenig
Wade Stevens
Stage 7
RobZ
What's in it.
REDs LS7 MID block. 4.198 bore.
Callies 4.125 Magnum crank
Compstar H Beam 6.125 rods
Wiseco pistons and ring package.
Morel lifters
PI 275 Cathedral port heads
Ported and modified Harrop 55mm intake
Kooks 1 7/8 headers
Cam 255 263 .67x lift 110
Big Stuff 3 to control it.
What did it do.
http://www.streetfire.net/video/ls7-...-2_2290861.htm
Thanks for the help and support from:
Wildgoose Performance
Erik Koenig
Wade Stevens
Stage 7
RobZ
Last edited by RAMPANT; 08-17-2011 at 07:27 AM.
07-30-2011, 03:22 PM
#4
What I do love about the intake is the throttle response, zero hesitation tipping in or lifting off. Makes a huge difference in the cars handling.
Last edited by RAMPANT; 07-30-2011 at 10:32 PM.
07-30-2011, 05:46 PM
#6
Do you still see red Xs? I just changed the permissions. It was those with a link, but sometimes it does not work. So it is fully opened now. It should be a graph and a data list.
Last edited by RAMPANT; 07-30-2011 at 05:55 PM.
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07-30-2011, 06:38 PM
#8
It was nice and cool the first time with the 455 back in Dec 2008!
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I will get started putting it in likely next weekend or the week after. More than likely September before I am out and rolling with a dyno tune.
07-30-2011, 06:38 PM
#9
705/663, the very first full run was 695, so it was really close out of the gate and 700 kept teasing us. We had one at 699.6 peak and I had seen 700 on the screen but it must not have been a data point. So that run in the video had several 700s showing. I knew it had to have broken it then. I also liked that this motor like my LS2 412, seemed to like to be hot. That run was at 160 but was about the third pull in 10 minutes. We tired one with the coolant at 130 and it dropped to 695 again. So that is a good thing, I need to order up a 160 T Stat.
Do you still see red Xs? I just changed the permissions. It was those with a link, but sometimes it does not work. So it is fully opened now. It should be a graph and a data list.
Do you still see red Xs? I just changed the permissions. It was those with a link, but sometimes it does not work. So it is fully opened now. It should be a graph and a data list.
08-17-2011, 08:58 AM
#15
No real issue with the Harrop, though it flowed poorly as cast. 283cfm. So we ported it and I had a set of new throttle shafts made. I flowed close 330cfm when we were done. The shafts were worth 12cfm alone.
The issues I had were mainly with piston rings falling apart. I had 71% leak down on one cylinder and 22 on another.
It never seemd to perform correctly and had high oil temps. Still trapped 125mph the week before that picture though.
I bought the heads and cam from Stage 7 as he had great success with a Harrop on them and I only had 11 fewer cubes. So we were confident it would work well. I think 2" headers would have helped, but it has nice low end torque for street and autocross use.
Last edited by RAMPANT; 08-17-2011 at 09:31 AM.
08-17-2011, 09:31 AM
#16
TECH Apprentice
any idea what the 283/330cfm is in comparison to something like a fast 102mm
Also im not sure how it works but if your intake is flowing 330cfm does that equal total air flow of 330x 8 =2640
which would still make a high rise intake marcella with 2x 2000cfm throttle bodies carb style efi flow alot better?
like this:
http://www.youtube.com/watch?v=r0oodHrDAfc
http://www.youtube.com/watch?v=QA-uszLNcsU
Also im not sure how it works but if your intake is flowing 330cfm does that equal total air flow of 330x 8 =2640
which would still make a high rise intake marcella with 2x 2000cfm throttle bodies carb style efi flow alot better?
like this:
http://www.youtube.com/watch?v=r0oodHrDAfc
http://www.youtube.com/watch?v=QA-uszLNcsU
Last edited by O.N.; 08-17-2011 at 09:40 AM.
08-17-2011, 09:46 AM
#17
What we noticed on the flow bench was that the inline restriction was not the total flow. When the heads flowed 330cfm and the intake 283, and both bolted together it showed a flow of 305. So it seemed to find the aproximate middle point, as though the heads were able to pull on the intake. That said the higher you can get every link will offer an improvement in the engines peak potential, but you may sacrifice the bottom end in going to big.
I think there is a lot to be said for a well matched set of components and I am not the guy to talk about that theory, there are much better on here than I.
I think there is a lot to be said for a well matched set of components and I am not the guy to talk about that theory, there are much better on here than I.
08-17-2011, 10:02 AM
#18
TECH Apprentice
im thinking about some itb's for my GTO 454 but if the twin 2000cfm like in the video is better.....umm i still dont know, which one do you think is best for highest hp drag racing?
08-17-2011, 10:10 AM
#19
The ITB intake tames a big cam. If you like cam lope, it is not the intake for you. It is one of the reasons I wanted it. On the street, people will have no idea what you have. Mine idles at 750rpm and likley could go lower, but I figured that was low enough. Considering I have a 253/266 cam that is a pretty mild idle.