What CR would you go?
12-30-2008, 10:40 PM
#1
10 Second Club
Thread Starter
iTrader: (21)
Join Date: Mar 2004
Location: Ft Lauderdale, FL
Posts: 808
Likes: 0
Received 0 Likes
on
0 Posts
What CR would you go? What CR would you guys go if you where building a 402 nitrous motor? Solid Roller. Race gas only. And is there any formula to how much hp gain you get from each full CR point?
12-30-2008, 11:50 PM
#2
TECH Fanatic
iTrader: (21)
Join Date: Feb 2006
Location: Allen Park, MI
Posts: 1,370
Likes: 0
Received 0 Likes
on
0 Posts
there are quite a few factors you have to throw in, im not a pro like some of the other people are on here, but cylinder pressure is a big factor, if your running 4 bolt per cylinder heads, its going to be harder to hold the heads down with a higher cr, because a big shot is going to make that cylinder pressure rise.
im sure a much more person will chime in and tell you what you need to do to determine what CR you should shoot for
im sure a much more person will chime in and tell you what you need to do to determine what CR you should shoot for
12-31-2008, 03:17 PM
#5
Nice T/A!! My 346 was 10.8 with the stock heads w/ETP Stage 2 CNC. The 382 w/same heads and cam is 11.6. I can't wait to try with 150-200 worth. I run 11.3 @ 119 N/A. The old set up w/150 picked up 1.2 secs. I'm hoping for a similar response in the spring. I'll bet you'll be pleasantly surprised with the nice mods. Let us know what your final race weight will be. To answer your initial question, I always ran 9.5-10.5 comp with a NX motor. I was told the higher comp won't be a problem with the tuning capabilities today. Good Luck with your new combo. Happy New Year!!
12-31-2008, 04:52 PM
#7
10 Second Club
Thread Starter
iTrader: (21)
Join Date: Mar 2004
Location: Ft Lauderdale, FL
Posts: 808
Likes: 0
Received 0 Likes
on
0 Posts
Nice T/A!! My 346 was 10.8 with the stock heads w/ETP Stage 2 CNC. The 382 w/same heads and cam is 11.6. I can't wait to try with 150-200 worth. I run 11.3 @ 119 N/A. The old set up w/150 picked up 1.2 secs. I'm hoping for a similar response in the spring. I'll bet you'll be pleasantly surprised with the nice mods. Let us know what your final race weight will be. To answer your initial question, I always ran 9.5-10.5 comp with a NX motor. I was told the higher comp won't be a problem with the tuning capabilities today. Good Luck with your new combo. Happy New Year!!
. My old set-up was a stock bottom with 224/228 cam (forget the lift) AFR 215 heads with full bolt on and a dry shot. Not the best of converters and a stock 10 bolt and I went 11.1 @121 N/A and 10.2 @135 with nitrous I was spraying like a 250 dry but the car wouldnt 60' my best was a 1.61. Now I have a fab 9 rear, double adjustable afco shocks, springs, mini tub, madman torque arm and all the goodies and I have spindles up front so finally the suspension should be the least of my worries. Im going to need the luck too so thanks! and Happy New Year to you too 
Thats what I was thinking. What fuel did you run?
Trending Topics
01-02-2009, 07:34 AM
#10
The torco stuff I have been runing has been good to me, but with some of the thigns that have happened there recently I don't know if I want to trust it anymore to be honest.
I"m gonna end up swapping to VP, but I really don't like the fact that I'm gonna be paying abotu 3 bucks a gallon more for C16 then I was for 118 torco.
I"m gonna end up swapping to VP, but I really don't like the fact that I'm gonna be paying abotu 3 bucks a gallon more for C16 then I was for 118 torco.
01-02-2009, 06:11 PM
#13
If you're trying ot run 13.5 to 1 compression with nitrous, you're gonna need more then 110.
110 with 13.5 to 1 just on motor is probably the BARE minimum I'd run, my car likes 114 to 116 n/a, plugs and performance was best with that, I tried 105 for a little while,a nd it never ran right and didn'ty perform nearly as well.
I went from 105 to 116 and picked up .2 and 3 mph from nothing else then the fuel swap fwiw, 114 it would run the same, but the fuel was only about a buck a gallon cheaper so I just ran the 116.
The 118 I was getting it for 65 for a 5 gallon pail, I think a 5 gallon pail of the VP116 is like 75 or 80, I don't remember what the guy told me.
I'm gonna ust go to buying it in 55 gallon drums, I'll burn about a whole drum in a season anyway so I mine as well just go that route, just have to keep it sealed up good and off the concrete floor.
Torco, before they ran into some trouble was GREAT fuel I don't care what anyone says. That 118Nos fuel would let ya run a good couple degrees more timing before you'd see any detonation, eastside ran the stuff in thier nitrous cars for years, and tried the other fuels, and always went back to the torco stuff.
I hate to get away from it, but with the stuff becoming a little unreliable, I don't want to take a chance.
110 with 13.5 to 1 just on motor is probably the BARE minimum I'd run, my car likes 114 to 116 n/a, plugs and performance was best with that, I tried 105 for a little while,a nd it never ran right and didn'ty perform nearly as well.
I went from 105 to 116 and picked up .2 and 3 mph from nothing else then the fuel swap fwiw, 114 it would run the same, but the fuel was only about a buck a gallon cheaper so I just ran the 116.
The 118 I was getting it for 65 for a 5 gallon pail, I think a 5 gallon pail of the VP116 is like 75 or 80, I don't remember what the guy told me.
I'm gonna ust go to buying it in 55 gallon drums, I'll burn about a whole drum in a season anyway so I mine as well just go that route, just have to keep it sealed up good and off the concrete floor.
Torco, before they ran into some trouble was GREAT fuel I don't care what anyone says. That 118Nos fuel would let ya run a good couple degrees more timing before you'd see any detonation, eastside ran the stuff in thier nitrous cars for years, and tried the other fuels, and always went back to the torco stuff.
I hate to get away from it, but with the stuff becoming a little unreliable, I don't want to take a chance.
01-06-2009, 10:12 PM
#14
TECH Resident
iTrader: (46)
Join Date: Dec 2001
Location: Some where in the Corn Fields of Illinois
Posts: 821
Likes: 0
Received 0 Likes
on
0 Posts
Stick with somewhere between 13:1 and 14:1. I've ran my old motor at a hair over 14:1 for 2 years and it loves the spray.... But my camshaft was designed around that too.
My new motor is 13.5:1.........
And the ONLY fuel I'll run, VP NO2 fuel, 120 octane.
My new motor is 13.5:1.........
And the ONLY fuel I'll run, VP NO2 fuel, 120 octane.
01-10-2009, 11:23 AM
#17
TECH Enthusiast
iTrader: (19)
Join Date: Dec 2001
Location: deam land
Posts: 623
Likes: 0
Received 0 Likes
on
0 Posts
If you want your parts to live longer and heads staying down longer, I was told 12.0 to 13.0 is the range you want to say around. Mine is 12.2 to 12.5 and 1/2 studs with 6 bolts.