WicketMike

iTrader: (13)

Old setup was 222/224 cam with bolt ons and stock converter.

new setup is 231/237 cam with PP stage II heads, electric water pump and hi-stall conveter.

before and after its taking me 4.3x seconds to get from the 1/8 mile marker to the 1/4 marker. i looked on the database and it looks right compared to other people running 11.8x but i was running that before at 12.2's

with the new cam, heads and hi-stall coverter so far ive gained .4 tenths. 2 tenths in the 60ft and the other .2 tenths by the 330ft mark, after the 330ft mark its taking me the sametime before and after. so the converter is doing its job.

i dyno'd 403 to the rear wheels on the new setup and around 375 on the old setup.

should i be worried? should i look for something? race weight is 3600
my mph stayed the same around 114mph also

thanks!

Beast96Z

iTrader: (21)

It's hard to base gains off timeslips. Weather conditions vary so much, that it is easy to gain something here and loose there. I would assume that the "before" times were your best, and I doubt the weather conditions were as optimum as they were when you ran your best before. I'd wait on a day where it is going to be nice and cool out, and I'm sure your times will come up. You "should" be running 11 sec passes at around 120 or so.

93octane

Have you had a tune since the new cam?

ACCELR8

I noticed a lot of people are viewing this post, but not too many people are replying. So I give it a shoot.

I'm no expert, but I would think that you would want to look at your mph at the 1/8 mile and 1/4 mile for the new setup compared to those values for the old setup.

your average acceleration at top end = (velocity at 1/4 mile - velocity at 1/8 mile)/(time to get from 1/8 mile to 1/4 mile).

I would calculate your average acceleration for both setups and see were you're at. In addition, the faster you're going the more power is required to accelerate the car at the same rate of that same car moving at a slower speed. (e.g., a car accelerating from 60mph to 90mph at a rate of 400 ft/sec^2 requires more power than that same car accelerating from 0 mph to 30 mph rate of 400 ft/sec^2). Therefore, if your 1/8 mile mph is different between the two setups, which it probably is, you'll have to take that into consideration.

Again, I'm no expert, but that's how I would approach it.

For a more practical approach you may want to post this in the drag racing section.

Hope that helps,

Jim

badboy4life

try tuning and get the car on a diet.

onyxxtreme

iTrader: (4)

post your whole time slip info, from the old and new setup
that may help some
but if your saying you trapped 114 before AND after, something is wrong
but your also saying you gained 28rwhp on the dyno with the new setup. That right there is telling you your new heads/cam setup isn't the culprit, unless your car is running worse now than it was on the dyno
or maybe the weather was just plain horrible at your latest track outing

93LS1RX7

iTrader: (8)

Could a very loose converter cause the mph loss to? He went to a high stall with I would think would gain off the line but loose some on the big end.

CHRISPY

the converter can eat hp and also cause mph loss. But should sixty and run through the 330 better. Might want to try a lockup in third gear. did you tune the car? I would expect 2-4 tenths and 2-3 mph improvement depending again on how loose the converter is.

PREDATOR-Z

Also traction is a factor. What kind of tires are u running?? Are you hooking right off the line?

WicketMike

iTrader: (13)

thanks for the replies.

the da' was around 1500 feet about the same on the old setup those days.
ive tuned the car myself using ls1 edit and also have a wideband o2 (LM-1 innovative).
traction wasnt the issue, i had a 1.640 60ft time and lifted the wheel off the ground.
i dont have the timeslips with me (at work) ill look them over and post them later

thanks again!

CHRISPY

with a 4000 stall converter and that power you should run low 1.5 sixties

foff667

iTrader: (2)

consider though my setup made peak tq at like 5000rpms and didnt gain over just bolt ons till like 3800-3900 rpms so really even a 4000 vert is pretty small for this cam IMO.

Ragtop 99

iTrader: (7)

1500' DA and full wieght won't give you low 1.5 60'.

I'd be concerned about mph being unchanged and so low. Even in that DA, I would expect another 2 mph.

Plum Crazy Rob

iTrader: (3)

Have you adjusted your shift points to match with the new cam making peak power at 300-500 RPM or whatever higher??? What stall converter? If you said in this post, I missed it somehow. foff667 is exactly right in thinking that if your stall is TOO SMALL for the cam your combo will be off because the basic stall and shift extension will both bring the engine down too low in the power band. ...

Remember, the basic deal is to maximize the average RWHP applied throughout the run, which is one of the basic reasons for shifting a few hundred RPM AFTER the power peak has occured - so that engine is off as few HP as possible from the peak either at the minimum RPM, OR maximum RPM you see during a run. Have the dyno shop print you the text file showing the HP vs RPM in 100 RPM steps and adjust shifts accordingly to maximize the
area under the HP curve you are applying...probably telling you stuff you already knew about....

Car diets are always good, I shucked 200 lbs and went from 114.4 MPH to 117.4 MPH in the same DA (1500') without doing any "permanent" alterations to my car....
!catback -70 lbs
!clunky stock wheels for Bogarts and skinnies ~-50lbs
!full size battery for dry cell -30lbs
!beer gut -34 lbs

WicketMike

iTrader: (13)

the one thing i did leave out was that i have 3 cutouts and with the 2 cutouts open on the ypipe i gain 20rwhp vs. them being closed. so with them closed just like on my old setup, i really only gained about 10rwhp from old setup vs. new. and that might be just from the electric water pump.

Got Me SOM

iTrader: (2)

cutouts are garbage. I suspect your gains are really from your converter and quite possibly your elec wtr pump.

it could be that your converter and shift points aren't matched up and/or your tune might be a little off. i think that cam makes power all the way to the atmosphere. probably have to shift her close to 6800 possibly 7 grand before going to the next gear.

before you start pulling weight out, figure out what's wrong, correct it (if at all possible) and see how repeatable your times are.

your converter may not be as efficient so its eating up some of your hp on the top end. that's a trade off. locking the verter in 3rd might help.

keep playing with it till you get it right.

I suspect after all is said and done you might gain another 2 tenths or so but that's it. when your car gets faster its harder to take tenths off.

good luck

by the way you never specified your rear gear. that could be part of the equation too

PREDATOR-Z

That is a comment.

destroyerSS

iTrader: (2)

Sorry to hear, Kinda sucks when things don't go as planned . I would think that with the cam alone you should be trapping at 114-115mph. This cam is a proven cam but i think the heads leave alot to be desired! About the weight i would not do anything right now till you find out why there was no improvement over your old set up. The loose converter might be eating up some MPH but you still should be at least in the 117-120 mph range with the TSP231/237 and a stage 2 head setup. Good luck and hope it works out for ya

WicketMike

iTrader: (13)

i have 3 cutouts. one on the i-pipe and 2 on the y-pipe. With the 2 closed and only the 1 on the i-pipe open i gained about 20rwhp vs. all closed. then with all 3 opened i gained another 20, so 40rwhp from all 3 open vs. closed. i know some people say b.s. but i have dyno and 40 people that witnessed it.

i think i might be shifting way to early, on the old setup and still now. i am shifting around 6400 rpms. i will move that up and see what happens.
thanks guys

bigeller

iTrader: (2)

I agree.. Your MPH is off.. Could be something very minor in your tune. I make 408 unlocked hp with my TSP 228R cam and ran an 11.74 @ 117 in 2000' DA weather right after it sprinkled at Texas Motorplex. That was with the worst launch of my life .... A 1.72 60' and 3670 lbs race weight.

Keep tweakin it.. You'll get it hammered out. You have the power to get mid 11s @120 easy.