visionpb16

I have a 1991 Camaro Z28 with a 5.7 TPI engine. The mods to the engine are: bored .30 over, ported heads, 1.6 roller rockers, a hydraulic roller cam lift .495/.502 (here is a link to the cam specs http://store.summitracing.com/partdetail.asp?part=CCA-08-422-8&autoview=sku), mini-ram intake and, 58 mm holley throttle body.

The car has a 700R4, I had the tranny rebuilt but the car still has a stock stall in it. What size stall do I need? Also I was wondering what difference the stall makes. I know it lets you launch at a higher rpm, but if I lauch the car it doesn't hook up anyway. And I know that a higher stall will change the shift down points when its in drive and you floor it but can't I just drop it down manually? Will it make a difference in my 1/4 mile time? Also from what I have read that a larger stall lowers MPG, how significantlly?

customblackbird

iTrader: (15)

mini ram is alot of intake for a ported stock head. so is the 58mm TB but some ppl will argue that it doesnt make a diff. you would have been fine with a 48mm stock TB or a 52mm max. not untill u throw more cam and larger heads will u need a 58mm, the stocker can support 350-400hp. a 52mm tb can support prob up to 500-550. and the 58mm is all and beyond. and the cam doesnt show up on the link... sends me to arizona state. i checked the part number and its a 218/224 duration and a 110 lobe.... also you kno it says its not computer compatable. the 110 lobe seperation will not be easy to tame with a computer if not impossible... a 113 lobe is alot easier to tune.

u should look at the comp cams XFI series.... radical designs for EFI. look at the XFI260. im goin with the XFI 280 230/236 for my HSR 383.


a higher stall will kill ur gas mileage. not great for saving gas at all. higher stall will allow u to rev higher into the engines RPM range before the stall grabs and pulls through the brakes. means the engine will launch higher in the RPM range.i would say that your small duration cam will prob recomend 2000-2200. my XFI280 with 230/236 and comp cams recomends 2400 stall.

a higher stall will make it even harder to launch/hookup. what you need is traction and higher stall which will lower your ETs etc. the higher the stall will mean it will take more RPM to move the car. it also depends on your motor and injector sizing etc. think of it as when u step on the gas before u did all this work... the car would move instantly... not imagine u having a 2500 rpm stall converter.... at a light you would step on the gas and the car would not move, your engine will rev to about 2500 before it even starts to move.... get how ur gona be wasting more gas?

unless u plan on racing the car a lower stall will help around town and MPG. as well as throttle response etc. again i would think that comp cams would recomend a 2000-2200 stall. give them a call.

what size injectors are u running? 24lb? i would say your stock 22lb would have to be set to about 50psi i would say just go with the 24lb.

visionpb16

The link worked for me here is the specs thought:
Brand:COMP Cams
Product Line:COMP Cams Xtreme Energy Camshafts
Part Type:Camshafts
Part Number: CCA-08-422-8
Cam Style: Hydraulic roller tappet
Basic Operating RPM Range: 1,600-5,400
Intake Duration at 050 inch Lift: 218
Exhaust Duration at 050 inch Lift: 224
Duration at 050 inch Lift: 218 int./224 exh.
Advertised Intake Duration: 270
Advertised Exhaust Duration: 276
Advertised Duration: 270 int./276 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.495 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.502 in.
Valve Lift with Factory Rocker Arm Ratio: 0.495 int./0.502 exh. lift
Lobe Separation (degrees): 110
Intake Valve Lash: 0.000 in.
Exhaust Valve Lash: 0.000 in.
Computer-Controlled Compatible: No
Grind Number: CS XR270HR-10
Quantity: Sold individually.

The 1.6 roller rockers also increase the lift. And I do think that a 58mm throttle body is a little big but when I first started buying everything for this car (about 4 years ago) I didnt really know that much and just figured bigger was better. I have 30lb injectors just got them about a month ago cause the duty cycle was too high with 22lb and I am already getting around 80% duty cycle with the 30's. And as far as tuning goes im using the EBL flash system and it took a while to learn and I had to ask alot of questions but the car is pretty well tuned right now. The whole computer controlled compatible thing alot of cams say that from the ones i looked at, the lt4 hot cam says that too, if you just look at the cam and not the whole kit and there is alot of people running that cam.

91interceptorZ

iTrader: (3)

also what size tire?? stock? and what gear are you running and what are you planning in future and what do you do with car, street/strip, bracket??? Don't put a stall in with a gear like a 2.73..you'll burn trans. out of it....just a thought

visionpb16

I just have the stock 245/50/R16, Im not sure what the gearing is cause I have tried to figure it out but i have read both 2.73 and 3.23 was an option but i dont which one it is. The car is just a daily driver but I still want to take to the strip on weekends and stuff.

91interceptorZ

iTrader: (3)

2.73 would be bad with stall...burn trans. out....but ya know if your going to run like a 2200-2500 stall or somewhere low there is a little trick that will save ya some money that I actually have done.....go get a convertor for a chevy s10 blazer....they have a flash stall around that range, and a TON cheaper than a convertor from let's say B&M or someone..but it works great...I've done it twice.....and works just the same..

joeblue83

iTrader: (8)

what you should do is put a 3.73 posi along with a 2500 lockup converter along with a tranny cooler, and you will be pulling off great 60 foots and still maintain good mpg, and you will be less likely to burn up your tranny. With my combo I maintain 20 mpg

91interceptorZ

iTrader: (3)

agreed.....

customblackbird

iTrader: (15)

im stiff stumped on how ur using the 30lb injectors.... they are way to much for a stock ported head and miniram.... id say ur making maybe 350hp. those 30lbs should be flooding that bad boy.

still the LT4 hot cam has a wider lobe... 113 i think... thats what is making it non computer compatable but hey... if u got it working then great.

agreed the 2.73 is poo and a higher set like 3.45 or 3.73 would be better and will like a higher stall.

friend had a truck converter installed on his camaro and it would stall everytime put in drive... the stall was too low, never heard of the S10 thing.

91interceptorZ

iTrader: (3)

Yeah...mine stalls up around 2500 or so..Learned that from a trans. guy whom built my tranny.....I also agree on the 30lb injectors that it's to high..but I have a xtreme fuel cam with 113 sep...and it's designed for computer car....works good in mine....I was told they use the wide lobe sep to get the computer to work with higher lift cams..of course mine has been re-burned but that's just what I understood...but I've been wrong before plenty of times....lol.

visionpb16

Why is a 110 lobe separation harder to tune?

I dont seem to be having any problems with 30lb injectors. I can just lower the pulse width of them if they are running to rich, and all my afrs are good (I have a wideband). Im sure if you put 30's in a stock car with the stock computer you would have some problems, but im running the EBL flash so I have more control over the computer. And also my duty cycle is in the high 70's at WOT with the 30's so I dont think 24's would be able to handle it at WOT.

But thats not really what my question was about. How difficult is it putting difficult is it to put in a new stall, it's just a new torque converter right? Also about changing the whole gearing thing, do I have to get a new diff, or can you change out the gears in the stock diff?

customblackbird

iTrader: (15)

ive gone to a few chip burners and they wont touch a tight lobe like 110 or a cam that has more duration than 220degrees for the TPI. they say its too hard to tune (with a stock ECM etc)

what is your expected HP output? trying to figure out how they are working at high 70s duty cylce. i dont think your pushing close 400hp. which is territory for 24lb. up to about 425-450hp.

a new stall is just a new tq converter.... u might get it in when its on the car... not sure ive never done it like that or u will have to take out the trans to get it on the shaft. easyiest sumtimes is taking the motor and trans out at the same time.

i wouldnt do it since u dont seem to kno much about it. esp the rear gear. its a simple gear swap if u buy the gear for your 10bolt or 9 bolt 7.5 or 7.625 ring gear. but its not simple. u will have to rip the whole center section out then put it back together then set all the lashes and wear tooth pattern. usually easy to just pay someone. if your off by alittle bit ur rear wont last long and it will make alot of noise

visionpb16

I hope to make around 380hp but I dont think its happening, probably close to 350 is a good estimate.

I haven't ran the car yet in the 1/4 mile but I want to get into the 13's and I don't think its there yet so Im trying to get the basics of the car set where I want before I do anything else.

I think I need to go the the tranny shop I had it rebuild at and see what torque converter they put in it cause i know they said that they put a higher friction one in or something to make it shift harder, then go to a differential shop and ask about changing the gearing. I think that putting in a new torque converter and changing the gearing is something that I would like to learn to do myself incase i wanted to do it again in the future. I'm only 22 so I have learned alot about car from my experiances with this one but I still have a ton to learn.

customblackbird

iTrader: (15)

yea im only 24. i got my stock 350TPI with some intake mods and exhaust to run 14.8 with only one wheel (posi is shot) and 3.27 stock gears. that was bc i had horrible 60' somewhere in 2.2-2.4 range. with all the suspension mods ive done and with 2 wheel traction i should be ripping 1.6-1.8 60'. when my 60' dropped from 2.8 to 2.2 i lost over 2s from a 16.8 to 14.8. that was with 1700-1800 stall.

you should be able to rip mid to low 13s with 350hp. i still dont think ur gona be making that with the stock ported heads. but with good traction and better gears u should be able to. im guessing u'll be pushing 330hp but u lost a good but tq with the miniram.

no such thing as a higher friciton TQ converter.... the only clutch part is for the locking ability for 4th gear highway cruising. the converters just stall... which is where the turbines spin enough to engage the other side... there is still slippage. they aren only locked in a "locking" tq converter for 4th gear.

if your gona be doing a gear change... not sure how well ur rear is in as far as shape...if its stock or not in great condition i would throw in a new posi... go for eaton... auburns are ok but they suck as in they wear out and arent rebuildable also they throw crap in the fluid when they wear.

eatons are stronger and rebuildable.

visionpb16

I read a little on heads, and everyone says stock heads even if ported still dont flow as well a aftermarket. What heads are do you think are good for my mods?

customblackbird

iTrader: (15)

your working with 20yr old technology and castings.... the new aftermarket is way ahead of that. most pocket porting will give u 15hp-30hp. 30hp is a more expensive porting job etc... so the money u spend on porting and rebuilding the heads will prob cost more if not the same of the aftermarket heads and u still one flow as much.

your engine has a nice intake that wants to revvvvvv! so larger heads are in order. your cam is also alot like the GM HOT CAM... which is designed for short runner EFI intakes like LT1/LT4 etc and also work well with HSR and miniram. i think u should be looking in the 190-200cc head range. the best being the AFRs but they are also the most $$

with a good flowing 190-195-200cc head like an AFR and that cam and intake u should be able to easily make 450hp. but rememebr that ur heads and cam and intake means ur gona be reving to above 6K prob. so once u figure out your power range and power output then u match the TQ converter stall to it.

also if your reving higher like 6k with the combo i mentioned ur rear gears will have to go up like 3.73. those 2.73s are gona make it a dog.

again look for heads in your price range... like patriot, AFR, edelbrock, RHS, brodix, trickflow. and dont be afraid of iron heads, altho heavier they are basically the same as aluminum. as long as the designs are good. RHS makes nice iron heads. your gona want heads that flow in the 250-270cfm range at like .5-.6 lift since thats where your cam lift is.

visionpb16

so i was looking at alot of different heads and trying to figure out which are right. what is the significance of the combustion chamber size? It would seem like you would need more gas for a larger chamber. There is alot of specs that I dont know exactly what they mean, like valve angles. I'm just trying to figure out what heads will work with the engines current geometry without changing anything else but I dont know if i know enough to do that. Do you think its possible to change the heads with out pulling the motor. Cause I have already done that twice and this motor has only been in there like 600 miles.

customblackbird

iTrader: (15)

lol oh man, u dont kno that much about cars do u lol. its ok i'll help u out. your stock heads have 58cc combustion chambers... larger cambers means more room above the piston so say u have 9.3:1 compression with 58cc heads... so putting on a head with 64cc combustion chambers means ur fillin a larger space with the same amount of gas/air etc so your compression will drop. its like pouring a small glass of water into a larger glass thats empty... theres more room in the larger glass with the same amount of fluid.

valve angles i think u mean valve... and the valve angle job. thats the degree of cuts behind the valve that make up the seat. more cuts means more flow well not totally but most likely. stock is 1 cut at a 45degree angle i think... 3 angle valve job means they add 2 extra cuts to increase flow around the valve seat. some go as high as 5 angles but some depending on the head 5 angles can hurt flow compared to 3 angle valve job. this is an easy way to gain flow and HP. most if not all aftermarket head companies do this.

there are a ton of heads that will just bolt right on. u need to give us a price rrange. and if u want aluminum or iron heads. and u do not have to pull the engine to do a head swap. its pretty easy in the car. ive done head gaskets in my car with no real problems.

i dont kno ur compression ratio but a larger combustion chamber size will lower compression which is good if u want to run pump gas (only if your comp ratio is too high for pump gas) but u also lose alil power bc your not compressing the air and gas as much so u get a cooler lesser bang. if yours is a stock comp ratio then u would prob be better off with 58cc combustion chamber heads. you could put 64cc chamber heads on but u will have to calculate comp ratio and then figure out what thinner head gasket to use to bring compression back up.

a hanyes manual will tell u how to take the heads off without removing the engine... its basically just disconnect everything off the top of the engine. intake. accessories. electrical, and exhaust manifolds/headers. and they come out when u take the head bolts out

visionpb16

yea i really dont know that much about cars. I would definitely say that i know alot more than the average person but when it comes to details and specifications i dont really know that much. My dad and I pulled the motor ourselves both times but I had a friend over when it came to putting it all back in. And we didnt build and balance the motor ourselves we had a shop do it but I did choose what I wanted going in the motor from reading on the forums and asking people. I really wanted the lt4 hot cam cause i read thats what alot of people on here were running with the miniram. but the guy that build the motor didnt trust gm performance or hadnt ordered from them before so he said he would find a similar one from comp so thats how i ended up with the cam i did. And when the motor was getting built I asked the guy about heads not knowing anything and he said that porting them would be just ask good as newer heads so thats why I still have stock heads.

There is an explanation for every mod on that car. But i think not knowing that much about cars and not paying a shop to do everything, I did alright there are things that I would have done different with the motor cause its on its second rebuild. First motor with a different/smaller cam had a custom chip burn by TPIS ended up dumping too much fuel in it and washing out the cylinders, we thought the rings didnt seat but it was a computer problem. Thats why now I have the EBL flash. Its all been a learning process. With the EBL i had to rewire the computer not really hard but just kinda tedious. Then learning how to use it and finally getting the car running right with good afrs took some time but I really happy with the EBL and being able to control everything. I spent so many hours reading on tuning and still feel like I dont really know that much. I did find some websites with computer files from custom tunes in them for lt1s with the lt4 hot cams and lt4 intake manifolds. I stole spark advance tables from them and put them in mine, they made the car fell like a different car.

I'm thinking about spending about $2000 more on this car then if Im still not happy possibly an STS kit. For now i was thinking probably somewhere around a $1000 for heads, then I figure it will be around $400 for a torque converter, and then i will have about $600 left for gearing (i really doing know how much this will cost I looked at 3.73 gears online but i dont know like you said i might need a new posi and plus labor if i dont do it myself).

I dont have this money right now but I graduate college in may and start my a full-time job in june when I recieve my signing bonuses. So part of them are going into my car. At this point I have decided that I am going to start making my list of stuff I want to buy for this car and hopefully buy the time I have the money I will have figured everything out.

Originally when I decided to start really modding the car I was shooting for 400hp at the wheels and to break into the 12's. But it took awhile realize how much 400hp at the wheels is and how fast a 12 second car is.