hi, i'm hoping some of you could give me some input.
my car is a 1990 trans am 28000 mi currently with slp headers and cat back,paxton supercharger,msd-6al-btm the paxton currently is putting out 6 lb boost.
the parts i have already are
--afr 190 cc heads 64cc
--arp head and rod bolts
--pro magnum roller rockers
--asm runners
--edelbrock hi flo tpi base
--holly 52mm throttle body
--new timing chain
--30 lb fms injecters
-- spare 1991 tpi moter compleate
--zz4 camshaft
thinking of a stroker crank--and adding cubes 383 or just may upgrade to a new supercharger thinking a d1

question is this will be a street car not a strip car no more than a couple of 1/8 mi passses each year on street rubber.so what is best should i stick with the 350cu and get the d1 or go to the 383 and use the paxton for now???

do i need a new crank and rods for duribility?
what abouit a hi flo or a hi volume oil pump?

any other tip's would like to have this reliable enough to take 1000mi trips so i'd like to build it once and have it for the next 20 years.

 

A few preliminary questions:
1 How much power do you want to make?
2 How high are you willing to rev to make the power?
3 Is low end torque a high priority?
4 What are the specs on the ZZ4 cam?
5 How much fuel pressure are you running?

 

i need to add some things i forgot
i also have the racetronix hotwire kit and 255 pump running 50 psi currently,i have a fmu but it is not installed and would rather tune the prom than use the fmu(i have all the prom tuning stuff)

the car is a automatic,thinking of adding a converter when the moter is out

would like to be in the 500 hp range

being a street mostly car torque is inportent but the tpi should help this

dont want to rev over 6000,this should help keep the roller lifters from floating

the cam is somthing i have laying around that i've herd will be ok for this setup will lookup the cam specs.will get a new cam if necessary

thanks
pete

 

Okay, your plan is:
1 500 rwhp
2 6000 max rpm
3 To make more low end torque w/either stroker or bigger s/c
4 Not known yet
5 50 psi

Secondary questions:
1 What is your compression ratio?
2 Do you know the flow numbers on the heads?
3 Which of the parts listed are on the car now?
4 How much are you putting to the ground now?

 

I'm really curious to see how that ZZ4 cam does with a blower. I have one sitting around from the ZZ4 crate that's in my Dad's vette, I have no use for it myself but I've always wondered how it would do with a blower. Seems like it would do alright, lots of exhaust bias, decent lift for a street motor when used with 1.6 rockers, and not a whole lot of overlap.

 

thanks for the replys
here is some more info

the cam specs are
SDPC Part Number: 10185071
Manufacturer: GM Performance Parts
Duration @ 0.050" Lift : 208/221
Valve Lift : .474"/.510"
Lobe Seperation Angle (LSA) : 112
RPM Range : 1500-5500
Camshaft Type : Hydraulic roller tappet

the comp ratio should be around 9.5-1

the afr flow numbers are
.200 .300 .400 .550 .600

intake 129 240 260 262 262

exaust 108 156 178 192 194

right now the car has a stock 350 with the sc @6lb boost
it also has the slp headers and exaust other than than the msd box it is stock i'd estimate the power to be around 350-375 hp but have no hard numbers
pete

 

Thanks, Pete. I can see right away that your injectors will need to be upgraded and your heads/cam setup are not up to 500 rwhp. The heads are maxing out at about .400 lift on the intake and .500 on the exhaust, and IMO the cam's duration is low on both intake and exhaust, I would go up on the lift as well. and close up the overlap to at least a 114 lsa, maybe as much as 116. This should help keep the power band broad and not peaky. I don't know how attached you are to the heads or cam, or how much you are willing to spend to reach 500 rwhp, but the heads and cam is the first place to start. Going with forged components is never a bad idea, if you have the money for it. Stroking on FI is debatable. There are those that say stick to stock stroke, you will get better cylinder fills because the piston will be moving slower. There may be some merit to this, however, IMO, the longer stroke will give you more torque down low, better avg. power throughout the range, a better cruiser, and is a good option for a s/c application due to the pregressive nature of the boost. As far as a high pressure or volume oil pump goes, more oil is good, too much is not. High pressure can cause leaks and high volume can drain the oil pan at high rpms, neither are desirable. Between the two, I would go with high volume and get an aftermarket oil pan with about 7 qts and good baffling; or I would leave it alone since you don't plan on reving too high or running at elevated rpms for extended periods. If you are concerned about the stock oil pump, get a good oil pressure guage so you can monitor this for your own peace of mind.

This is how I see the decision making process:
1 forged or stock - if forged, go stroker, it doesn't cost much more, power is worth it, peace of mind knowing your internal components will hold up
2 match the heads/cam to the displacement - seek out a head porter w/good reputation or proven track record in FI, give him your plans, let him recommend heads/cam/exhaust pkg for your application, or let him port the heads and choose the cam and exhaust system that will optimize his head work
3 make sure the entire fuel system will support 500 rwhp without maxing out - at 43.5 psi, you will need 50lb injectors for FI, a boost referenced regulator that will add pressure as boost rises, and at least an additional pump that comes on when boost is detected
4 if your s/c setup does not include an intercooler, I would consider getting one. The more boost you create, the hotter your intake charge will get and to avoid detonation, you must back out timing or user higher octane fuel. I am not familiar with Paxtons, but Vortech and ATI both make good kits, but can be expensive by the time you get all the kinks worked out
5 tune, tune, tune some more - for this kind of power, I would not rely on just a generic prom burn for WOT, put it on a dyno and tune for the whole rpm band.

To me, power is important, but reliability and longevity are just as important. I don't want the fastest car in town that spends half its time in my garage because something else broke. I want a fast, good handling, all-around performer that will hang with the best of them, and outlast all of them. I have been collecting my go fast and suspension parts for over 3 years and it is all finally about to come to fruition. It has been a long and sometimes frustrating wait, but I have taken my time, planned well, shopped around for the best parts, and done it right so it will last. I have said it on several other posts and I will say it again, FI is not rocket science, but it does require a certain amount of research and knowledge to do it right. I think you are headed in the right direction by increasing your knowledge and asking questions.

I apologize this is so long, I tend to get a little long-winded. Let me know if you have any other questions and I will do my best to answer them or help find the answers.

Good luck,
Tom

 

The above post was very well said...couldn't agree with him more!!!

 

the afr heads are some of the best out if not the best.seems to me intake flow numbers become mute point once you add boost am i wrong here?

second the cam i know if a little small but the 1.6 rockers will add some lift,i also want to keep it very streetable.i'm talking to a comp cam rep to see what they recommend.

right now no intercooler on my paxton but using water alkly injection for cooling.seems to be working good right now.

looks to me that i should get the ati d1 so i can just add boost to get my results.am looking at the twin intercooled setup.

think i'm going to have the block splayed and go with the new sledgehammer 383 crank in summits catalog,some new rods and forged pistons. i've seen 383's dyno at 400 hp setup right but they were all carbed the tpi will hold me back but the sc should make up for the blockage.

thinking right now i'll do a base run with the new 383 and the paxton then if i'm not satisfied i'll add the ati d1.
i'll definatly go with the larger injecters thinking the 70lb and no fmu,will also upgrade the ecm to the 7749 from a grand national so it can see the boost and add fuel.
thanks for your input--i really appreicate it
pete

 

GNs didn't use the 749 ecm. Pretty much only the turbo sun birds and the Sy/Ty used that ECM. Good idea on the upgrade though.

I'd ditch the TPI in all honesty. It's a bottle neck no matter how you look at it (sucking air or blowing air through it).

As to the twin intercoolers... I'd pass and go with a single large one whether it's air to air or air to water.

 

yes i know the tpi is a restriction but i like the way it looks and the low end torque is awesome.plus people think that tpi cars are slow and cant hang with the 4th gens and vettes.yes i could upgrade to the entire 4th gen drivetrain but i just dont want to.

to be honest i dont really even want to clutter the engine bay with the intercooler setup as it just adds a lot of piping.

i think i'll try to stay with only the water injection and around 10 lb of boost.if it wont muster up the 500 hp maybe i'll spray it with a 100 hp kit as long as the block is built strong and the fuel is availible things should be fine.

with the 2 255 racetronics pumps i've got plenty of fuel.
pete

just like the sleeper look, right now my car looks pretty stock but runs low 13s with street rubber.

 

Sounds like you have made up your mind to go forged stroker and that is cool; I did the same thing. A FI motor is still an air pump, just like a n/a motor. The more air you can get in and back out, the more power you will make. The AFRs are good units and are probably working fairly well with your current setup, but even now the cam's intake lift is being hindered by the heads playing out at .400; the flow numbers flatten out here. Basically, in their current state, their limitations have been reached and will be a restriction in your quest for 500 rwhp. Intake flow (lift and duration) is never a moot point. While not as critical as the exhaust side in a FI application, it must still compliment the exhaust side. In a pinch, with the 1.6 rockers, you may be able to use the cam, but only if you have the heads reworked to take advantage of the higher lifts with special attention to the exhaust side. With the 1.6s, the effective lift will be .505 intake and .544 exhaust and you might gain a degree or two of duration, but IMO, this will not be sufficient, the duration numbers are not right and there is too much overlap. Talking to Comp is an okay place to start, but they will always recommend one of their off the shelf cams that will get you in the ballpark of the power you want to make, but it will most likely not be the perfect cam for your setup. I would still talk to an experienced FI head porter about this; they are usually more than happy to help, and it doesn't cost anything but a little time. It's like free legal advice; you just shouldn't pass it up. 70 lb injectors would be overkill and unless you think you might be making 600 or so rwhp in the future I would not go that big, it will be tougher to tune and might cost you some gas mileage, especially in town. Finally, spinning a s/c faster to try and compensate for an engine's inability to flow enough air to make the desired power output is not sound reasoning. You may gain a little more power initially, but you will quickly reach the point that the engine simply cannot ingest any more air. At this point, you will have driven the s/c beyond its designed efficiency range, and the intake air temps will rise dramatically causing detonation, and if you are at high rpms, even a forged engine may be only seconds away from a catastrophic failure. It is always better to determine where the flow bottleneck is and make your corrections there rather than push any component to or beyond its limitations. Remember, do it right the first time and you will only have to do it once.

You and I are doing some similar things. My goal is 650-700 rwhp and mid-low 10s without having to rev to the moon. I want good street manners, and excellent cruisability. I plan to auto-x and maybe road race as well as drag (got a track less than 10 miles away from my house), but drag racing is very hard on a car and I don't plan on doing a lot of hard launches. Besides, I don't want to put a roll cage in it, so they will probably restrict me. I live in the San Antonio area and want gobs of low end torque for tooling around in the surrounding hill country. I have a 382 stroked LS1, stage 2 o-ringed heads optimized for FI, a small (relatively speaking) cam (216/220 .525/.532 114 lsa), 1.8 rockers (stock is 1.7) making effective lift .555/.563 and maybe an extra couple of degrees of duration. But there are some important differences. I have the D1SC w/dual intercoolers, 72lb injectors, a $1000 fuel system, Accel DFI Gen 7 management system for gnats *** tuning, and a ton of other less relevant goodies. I, too was told that my cam would not allow me to reach my power goals, but I had done my homework and spec'd my motor out carefully. The cam (on a stock motor) has a power band of 1300-6300. The 1.8s will bump that up to around 1500-6500, the stroke will bump it back down to around 1300-6300. Still I was not sure, the seeds of doubt had been planted. So, I called Comp, they recommended an off the shelf cam that would get me to the power I wanted, but the power range was like 3500-6800. I told them I don't want a peaky, high-rpm cam, I want a cam with decent low end and strong mid-range. They said for the power I wanted it couldn't be done. BS. To make a long story short, I called the company I bought the heads from and talked their guru, told him which heads I had, gave him my internal configuration and cam specs. He told me that this particular cam works very well with their heads and recommended I stick with it. He said normally this cam would be a bit small for a stroker, but that the 1.8s would go a long way toward making up for that.
I guess what I am trying to say is that when I had doubt about my setup, I went back to the porter for his advice and I am taking it. If he had said no, and recommended a different cam, I would have gone with it. So, because you are planning on using heads and cam that were designed for a stock displacement n/a motor, I can only recommend that you take similar steps to make sure what you have will get you where you want to be. You asked for help in building a blower motor (which will apparently be stroked as well) and of all the things I have stated, I think this is by far the most important. After all, the heads and cam are the lungs and brain of the motor. If they aren't a match to the rest of your setup, you likely will not reach your power goals. Hopefully, some other guys will chime in and back me up, but I also welcome any constructive criticism as I am still learning, too.

Tom

 

thanks tom great reply,i understand your points and will look into having the heads ported for better flow.

the motor will be a stroked supercharged 350 splayed main, sledghammer crank 383 (forged) ,5.7 rods, ported afr heads,pro magnum roller rockers 1.6,tpi intake all aftermarket-holly 52mm tb--asm runners--edelbrock base all extrude honed for max flow.slp 1-3/4 headers and cat back,using a 7749 ecm
will use the paxton for now and run around 6 psi boost with 9.5-1 compression.the cam for now is still up in the air as i stated i have the zz4 cam left around from another project, but now i'm beleaving you that it is too small.so i'll be doing some homework as to what to use.
anyone have a proven setup? like i said i want to use this car more like a daily driver than a racer so nothing too radical please
thanks again for your input.
pete

 

an update, comp says use their cs xr269hr-12 cam

that cam specs out at 218/224 .495/.503 with a 112 lobe seperation this cam seems so close to the zz4 i have there wouldent be any reason not to use the zz4.

but in doing some research accel makes a supercharger cam that lingenfelter seems to like part # 74220
it specs at 215/220 .540/.555 with a 114 lobe seperation.
this seems to be more in line with what tom is recommending.anyone using this cam?????
thanks for the input
pete

 

Whoa, hoss. I didn't recommend a cam. My recommendation is talk to a head porter with a proven FI track record, give him your internal configuration, where and how much power you want to make, and take his recommendations for head work and cam. I merely stated what I was told by my head porter for my setup as an example of why it is so important to talk with them. While there are similarities between our setups, there are also some significant differences. Your stroke is (will be) 3.75", mine is 4.00", your bore is 4.00", mine is 3.905", your rods are (will be) 6.0", mine are 6.125", your pistions are recessed in the bores, mine stick out, and my heads (in fact, whole induction tract) flow way better than yours. These components, while adding up to about the same displacement and compression ratio, make power differently.

I am curious about your conversation with Comp. Did you discuss using your 1.6 rockers with that cam or that it was for a stroker, or for FI? Did they say why they recommended the 112 lsa? Did they specify a power range?

Thanks,
Tom