when should my torque kick in?
10-02-2006, 12:15 AM
#1
TECH Addict
Thread Starter
iTrader: (8)
Join Date: Apr 2003
Location: Honolulu HI
Posts: 2,513
Likes: 0
Received 0 Likes
on
0 Posts
when should my torque kick in? im trying to figure out when and where my car should start to pull. it just doesnt seem to have a great amount of pull under 2500 and i figured it should have some. here are the list of mods. can anyone take a guess? what should my powerband look like?
hpe 370, f13 112, stock ls6 heads, ls6 intake, lid, ported stock tb, 3.90 gears in my 9", svo 42# injectors, u/d pulley, LTs, catted y, cutout. Im going to dyno it on the 14th, but im wondering if im missing power under the curve or if thats just too low of an rpm.
hpe 370, f13 112, stock ls6 heads, ls6 intake, lid, ported stock tb, 3.90 gears in my 9", svo 42# injectors, u/d pulley, LTs, catted y, cutout. Im going to dyno it on the 14th, but im wondering if im missing power under the curve or if thats just too low of an rpm.
10-02-2006, 04:34 AM
#4
TECH Addict
Due to cutain area OHV setups (2v per cylinder) have a smaller rpm range. This means to get more power you move the power up the rpms. You will there for loss some of the lower end potential. This is because at said rpms you will be lower down the torque curve.
Do you have a dyno of your setup?
As HP is a function of toqrue you will not have much accelaration from low rpms by comparison.
HP = torque x rpm / 5252
So even if you engine makes 300lb ft @ 2000rpm it's still only 114HP. So acclearation won't be startling. (Even 500lb ft @ 2000rpm is only 190hp).
Do you have a dyno of your setup?
As HP is a function of toqrue you will not have much accelaration from low rpms by comparison.
HP = torque x rpm / 5252
So even if you engine makes 300lb ft @ 2000rpm it's still only 114HP. So acclearation won't be startling. (Even 500lb ft @ 2000rpm is only 190hp).
10-02-2006, 05:37 AM
#6
TECH Addict
If you don't have a dyno I guess you also don't have a tune?
If so then I would suspect a good tune should make a noticable difference. What are the specs of the F13, I don't really know a lot about it? I think it's a pretty sizable cam isn't it. which means it's probably happy from 2400rpm upto mid high 6000's?
I really have no idea, but most of the large cams seem to be happier in that rpm range. Where as stock is quite happy from 1500rpm or lower, but they are out of puff at 5800rpm or so.
If so then I would suspect a good tune should make a noticable difference. What are the specs of the F13, I don't really know a lot about it? I think it's a pretty sizable cam isn't it. which means it's probably happy from 2400rpm upto mid high 6000's?
I really have no idea, but most of the large cams seem to be happier in that rpm range. Where as stock is quite happy from 1500rpm or lower, but they are out of puff at 5800rpm or so.
10-02-2006, 05:38 AM
#7
TECH Addict
Thread Starter
iTrader: (8)
Join Date: Apr 2003
Location: Honolulu HI
Posts: 2,513
Likes: 0
Received 0 Likes
on
0 Posts
no dyno, but i am tuned. i have HPT and a LC1 so i tune on a daily basis. the cam is a 230/232 112 +4 .598/.598. i cant cruise in 2nd gear going about 20mph and punch it and feel anything. i mean, i can light the tires up in first, but in 2nd i dont have much umph.
Trending Topics
10-02-2006, 05:55 AM
#8
TECH Addict
How does it pull up top?
I'm gonna gues the higher the gear the worse it gets in the low rpms? This is due to increased load on the engine. Sounds like a tuning issue to me. Does it splutter or stumble at all? And does it suddenly kick in really good at a particular rpms, more noticable than just coming "on cam"?
A dynotune should work wonders and willl highlight any issues also.
Tuning on the street is one thing, but to really see whats happening you need to load the engine, a 1:1 gear would be ideal (4th for M6 cars) but that means you'll have to pull high speed to cover the entire rpms.
A load bearing dyno like a Mustang dyno would be the best bet for tuning. The HP numbers will be lower than that of a Dynojet, but since they are inertia dyno's they don't load the engine the same.
I'm gonna gues the higher the gear the worse it gets in the low rpms? This is due to increased load on the engine. Sounds like a tuning issue to me. Does it splutter or stumble at all? And does it suddenly kick in really good at a particular rpms, more noticable than just coming "on cam"?
A dynotune should work wonders and willl highlight any issues also.
Tuning on the street is one thing, but to really see whats happening you need to load the engine, a 1:1 gear would be ideal (4th for M6 cars) but that means you'll have to pull high speed to cover the entire rpms.
A load bearing dyno like a Mustang dyno would be the best bet for tuning. The HP numbers will be lower than that of a Dynojet, but since they are inertia dyno's they don't load the engine the same.
10-02-2006, 06:01 AM
#9
TECH Addict
Thread Starter
iTrader: (8)
Join Date: Apr 2003
Location: Honolulu HI
Posts: 2,513
Likes: 0
Received 0 Likes
on
0 Posts
ill be tuning on a dyno dynamics dyno. they're much better for tuning. as far as the car pulling, it pulls very strong once it hits 3k plus. it doesnt sputter or anything of that sort. id say it does pull harder at about 4k. after that its all up hill. im just trying to figure out below all that. i guess ill compare afrs and see how close my WB actually is. ill be doing some logging and tuning tomorrow so we'll see what i can come up with.
10-02-2006, 07:17 AM
#10
TECH Addict
iTrader: (22)
Join Date: Sep 2004
Location: tennessee
Posts: 2,639
Likes: 0
Received 0 Likes
on
0 Posts
what is your timing at around 2500 when you are accelerating ? tq is what gets your car off the line or gets you moving from a low rpm but i wouldn't think an f13 cam would be too big for a 370 cube motor,it should be a great cam for that size of an engine.
10-02-2006, 07:21 AM
#11
TECH Addict
Thread Starter
iTrader: (8)
Join Date: Apr 2003
Location: Honolulu HI
Posts: 2,513
Likes: 0
Received 0 Likes
on
0 Posts
thats what i thought which is what led me to start this thread 
i dont have my tune on my, but here is a screen shot of my current timing table:
ve is pretty dead on. wot still needs some tweeking, but its pretty damn close too.
i dont have my tune on my, but here is a screen shot of my current timing table:ve is pretty dead on. wot still needs some tweeking, but its pretty damn close too.
10-02-2006, 01:38 PM
#12
Launching!
iTrader: (2)
Join Date: May 2005
Location: Rochester Mn
Posts: 285
Likes: 0
Received 0 Likes
on
0 Posts
Try more timing, add it via controls while your driving. I did this to my doggy TSP 231/237 and it improved noticably. I run a lot of timing down low without KR - it makes the car a lot more streetable.
10-03-2006, 08:56 AM
#13
10 Second Club
iTrader: (6)
Join Date: Jan 2006
Location: Hattiesburg, MS
Posts: 673
Likes: 0
Received 0 Likes
on
0 Posts
My car is the same way. It was tuned by the Vette Doctors and it doesn't come alive till about 3000 or 4000. Anywhere under that I think a golf cart could outrun me. 
