thunderstruck507

iTrader: (18)

Has it been tuned for the cam?

My car with headers, cam, ls1 intake, 3.42 12 bolt, 2.25" duals cutouts open, stock stall unlocked only did 325rwhp/340rwtq on a dynojet. HP was falling off quick at 5600rpm due to the ls1 intake. Mail order tune.

Switched to a fast intake, larger cone filter, and yank ss 3600 and was in process of dyno tuning when the driveshaft broke. Made 360rwhp@6100rpm unlocked exhaust closed on drag radials at 14.0 a/f in winter.

Fixed the trans, new hd driveshaft, 3" pipe to muffler then 2.25" out to back, underdrive pulley, and tuned down to 13.2 a/f and made ~350 rwhp/330 rwtq unlocked exhaust capped. 28* timing no knock retard. Car was heat soaked from driving 4 hours to get the tune, it was in the 90*s and at least 70-80% humidity.

But the car runs in the 7.7-7.8 range with slight wheel spin and traps 88-89mph in the heat and humidity (2600-3000 DA) so people keep telling me I'm where I should be for a 3700+lbs race weight and spinning the drag radials out of the hole (1.79 60ft).

Try it at the track, let us know the trap speed. On stock stall that car is going to run like absolute dog **** (bet he gets 2.0 60ft dead hooking) but his speed should still be close, might gain 1-2mph with a stall though.

Unlocked autos on dynos suck. Every cammed car is not going to hit 400rwhp...I've accepted that.

But with a cam that large he needs to get an intake and most important a stall ASAP or bolt on cars will embarrass his ***.

Finkledbody

Hes trying to keep everyday drivability and keep good MPG. Hes thinking if he gets a stall is going to destroy his MPG and he wont want to drive the car anymore. He actually traded a fully built 69 nova ss that was running low 10's consistantly for this bone stock 97 vette. He was tried of getting 2-8 mpg.

Ill tell him to check that out the next time I talk to him. I'm also thinking he needs a full tune up.

Not sure on the trap speeds nor if there has been any basic maintanence done. I'll try to get more info today if I get the chance to talk to him.

thunderstruck507

iTrader: (18)

a stall will have ZERO negative effect on highway cruising since it locks like stock and to be honest I don't notice a huge difference in town either...maybe 1-2 mpg

a tight stall like the Yank SS3600 is very efficient at low throttle, but makes a night/day difference at WOT

if he refuses to stall because he is that worried about MPG he shouldn't have cammed it, and especially not with a cam that large...it will run marginally better than if he had just done bolt ons and worse than if he used a baby cam like the ls6 cam

Tainted

iTrader: (9)

those numbers are mad low. and 01-02 ls1 heads arent much different.

you want the ls6 or 243 casting ehads which are much improved and even better when ported.

Finkledbody

A big stall effects MPG pretty bad here in Maine. Its extremely hilly with lots of curves and sharp bends, stop and go traffic and no where to really open them up. So you end up rolling around between 15-25 mph in most places until you get on the back roads where the speed limit is still 35; but there are no cops around to stop ya from getting on it. I have a yank 4k stall and I get horrible MPG's in the city (12 mpg) and worse mpgs on the backroads (8-10 mpg). You're right about the highway though, Ill get 28+ mpg.

Hes not worried about MPG, he just doesn't want 10 mpg in the city. I suggested he go with a 2800 stall cause that wouldn't change much except at wot. I think he'll be considering that option soon..

Yup yup the numbers are low. I think I'm ganna search some to see if I can find flow numbers for the older and newer heads to get a good idea of how different they are.

Im pretty sure hes not ganna do a head swap this year cause hes also building up a dodge ram cummins duelie and hes ganna be drag racing that thing to.

RPM WS6

iTrader: (3)

Not sure where people get the idea that an LS1 intake is so bad.

I made 360rwhp @6100rpm with a baby cam (221//.558), A4, and LS1 intake. Would the LS6 intake be better? Of course, agreed, no arguement there. But the LS1 intake isn't some turd that will hold all cammed engines down in the 32x range either.

thunderstruck507

iTrader: (18)

*shrugs* that's where mine was falling off and everyone told me it was the intake

after the intake swap it didn't fall off like that so I considered that a confirmation

I felt a HUGE difference above 4k rpm with the new intake

flintwrench69

iTrader: (11)

Same here, switching intakes made a big difference & that was before I changed the cam.

fccs

iTrader: (26)

I hate when people just say 1/4 times... like, say the damn trap speed as well.

RPM WS6

iTrader: (3)

Once again, an LS1 intake is not going to hold a cammed LS1 hostage in the 32x rwhp range. Will you see a gain with an LS6 or better intake? Certainly. But you can still make 350-400rwhp below AND above 6000rpm with an LS1 intake and NA setup. People were doing this in 2000 before the LS6 intake was even produced.

09camaro383

iTrader: (2)

RPM WS6 i get your point but also back then most people weren't running cams with 23*/23* 23*/24* duration the highest they were going was in the low 22*'s and that was considers a huge cam!!

CamaroZ28_LS1

iTrader: (5)

I have almost the same cam, 221 // 561 lift on a 114lsa +4 w/ 799 heads and LS6 intake/ full exhaust and put down 380whp on a mustang dyno. His cam should net him over 400whp or close to it with stock intake and heads.

RPM WS6

iTrader: (3)

There seem to be two seperate possibilities happening in this situation.

- Is the car in question making lower numbers than it should for the engine setup?

or

- Was this done on a mustang dyno, thereby explaining the lower numbers. I don't think this one has been answered yet.

In the first instance, assuming these are dynojet numbers, then yes; I feel the numbers are low *even for an LS1 intake*. First off, this is a C5 which uses an IRS and therefore should always dyno a bit lower than an F-body with the same setup on a stock geared 10-bolt.

There are several things that can be robbing power; less-than-ideal tune, poor compression, slipping trans, weak ignition or fuel delivery. These should be considered/checked.

Another issue are the cats. I noticed that it was mentioned this car has LT headers with cats. I've seen cats (even hi-flow ones) rob as much as 10rwhp on cammed LS1s, this is why I always recommend NOT using cats if you plan to build the engine, unless you have no other reasonable way around your state's emissions test.

Or there could be any combination of these issues all leading to lower than expected numbers.

I think before tossing any more parts at the car, two key questions need to be answered:

1) What type of dyno?
2) What were the before and after trap speeds?

I agree that the LS6 (or better) intakes will offer bigger gains with more agressive H/C setups. However, a cam in the 23x duration range should not be restricted to 32x rwhp based on an LS1 intake alone. I'm guessing there are other factors involved.

thunderstruck507

iTrader: (18)

I didn't mean to imply the intake was holding him below 350rwhp. My post was to simply outline how my car with similar mods dynoed...

Since I have thoroughly inspected the car, compression check, filters, ign, fuel, new plugs wires, ect. My numbers are still ****.

If he finds something wrong I would love to hear it because if his non-complete bolt on setup can do better it might give me some ideas. I figure if I was 350ish unlocked being locked would still only get me 370 on a good day. I was hoping to be much closer to 400 with my mods.

01ssreda4

iTrader: (96)

I saw a bolt on/Trqr V3 M6 with 853 stock heads and an LS6 make 420 to the wheels. Knock a couple off for it being an M6 and having a better intake. Numbers still dont add up.

flintwrench69

iTrader: (11)

Those numbers are way low for either dyno. With that cam it should be close to 400 whp.

I agree, theres something holding the car back. Theres no doubt not having the right stall isnt helping it any either. A stall makes a big difference on a stock car, how can this not be part of the problem?

Finkledbody

Sorry guys, I'm having a hard time getting all the information. I'm unable to get a hold of him so I can't ask about the trap speeds or where he got the dynotune done at. Also theres seems to have been some confusion on the cam he selected. He told me it was a torguer v2 but the specs are as follows. The cam is a 224/228 .560ish 114lsa. Thats not a torguer cam as far as I understand. But even than he should be closer to 370whp.


So we know having the LS1 intake is holding him back 5-10 whp
The older heads are holding back another 5 whp
The cats another 5-10 whp
A tune-up could free up another 5-10 whp and lets not forget the IRS.
He may not have had the most optimal tune either.

20-40 whp equals 347-367 whp which is a little low but leaves him closer to what I thought he'd be at. I'm going to try to get a hold of him today but it might prove difficult. The guy is busy this time of year with tourism an all.

Thanks again everyone for helping me get this figured out

thunderstruck507

iTrader: (18)

that's a pretty big difference, much lower duration much lower lift

Camaro_94

iTrader: (5)

numbers are pretty low.... Did he install it?

RPM WS6

iTrader: (3)

With the revised cam specs, I would expect that car to be right around ~350 rwhp with the IRS, A4 trans, stock LS1 intake, and cats. Give or take some depending on the quality of the tune.

So he's down about ~25ish rwhp for the current setup IMO.