I'm puting a Vortec 350 out of a 99 Tahoe in my 88 GTA. I am a chevy newbie I have always driven and modified Mustangs, everyone is telling me not to put to much of a cam in a stock computered car. How would the ZZ4 cam work? Can anyone recommend a better cam for this set up? The car is a Daily driver and the computer is stock.

Vortec 350 <-- Fresh
Stock TPI injection with LT1 injecters
1 7/8 SLP headers
2200 stall
Shift kit

 

The ZZ4 cam wouldn't be bad except the lift on the exhaust side is a bit much for the Vortecs without some clearancing (.510 lift if I'm not going crazy). The duration wouldn't have been bad for a computer car though. If you do some clearancing on the valve guide bosses/run better valve springs it wouldn't be a bad choice IMO.

You should be able to get any number of aftermarket cams that are around 210/220 duration at .050 which is what I'd be aiming for with a computer myself, w/ a max lift of ..470-.480 or less to run w/ the stock Vortecs.

I'm assuming you know you'll need a Vortec specific TPI intake manifold base for it.

 

I plan on getting the Holley stealth ram for the vortec style heads but for now I'm having the stock tpi intake machined.

 

I went with a TFS cam what do you guys think?

Cam Style: Hydraulic roller tappet
Basic Operating RPM Range: 2,100-5,600 RPM
Intake Duration 050 inch Lift: 214
Exhaust Duration 050 inch Lift: 220
Duration at 050 inch Lift: 214 int./220 exh.
Advertised Intake Duration: 270
Advertised Exhaust Duration: 276
Advertised Duration: 270 int./276 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.452
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.465
Valve Lift with Factory Rocker Arm Ratio: 0.452 int./0.465 exh. lift
Lobe Separation (degrees): 110
Intake Valve Lash (in): 0.000
Exhaust Valve Lash (in): 0.000
Computer Controlled: No

 

Why go through the hassle of better heads when you can't get any more air to them? Buy the proper intake and a set of runners w/ the plenum mods or you will have wasted your time on the heads. The problem with TPI's is the lack of air getting to the heads, which is the problem you'll still have.

 

I realize the intake is the problem but I'm using the parts I had laying around, I stated above that I plan on getting a holley stealth ram when I have the extra money. i was just wanting to know how the cam would work with my combo.

 

The only thing I see that might give you trouble is the centerline of that camshaft. TPI motors typically like 113-115 degree centerlines for a good idle. You may have to get a chip burned to make it work to its potential. That cam isn't that much different than stock so I don't know if I would invest the money in that cam and then have to spend extra cash on tuning it. On the flip side it will work with the stock valve springs in those heads with out any valve guide modifications needed. I wasn't knocking you head choice (I am eventually going to put the SDPC kit on mine) I'm just thinking why spend the money on machining your intake when you can put that money towards your stealth ram. To realize the potential of the vortec's you will need to run the other intake parts I mentioned earlier.

 

Well if vortec heads and a new cam dont do that much, then how is SDPC getting 357hp, and 420 lb ft out of an l98 with vortec heads and a .525 in lift cam with a stock tpi unit with the exception of their vortec base?
I'm sorry but those numbers, both occuring at 4200rpm, seem like a pretty damn good improvement.

 

the sdpc car that you speak of, brian grubens to be exact, made 269whp with the exhaust un bolted from the cat. not very impressive. but this was with a stock tune. he had edelbrock runners and tb on it, and edelbrock headers. he had the gm hot cam also.

 

Thats what I'm hearing also. It doesn't seam like "the package" works exactly as advertised. From talking to a few people though it sounds like with some wise programing that package really comes to life.

 

Exactly,

My car was not that great compared to my , home port L98, with comp ex264HR, on a stock home port intake and base. not much better for the money - until I got it tuned - totally changed the car. went from a soft low end to a "beefy" low end bark/ pulse , the mid is great, and the top pulls "cleanly " to 6K

My car doesn't feel very fast, but have beaten 9 out of 10 cars on the street with this, including STi,(barely),M3(New style), NSX, Evo III - these were all stock cars, and I would only pull them by maybe a length or two. From a stoplight it pulls hard. soo this thing does well against lighter 300+HP cars. the pull from 70~100 in 3rd is brutal. even LS1s can't keep up.

And my car passes CA smog, with a emissions hooked up, including the SDPC external egr.

If you want to be king of the drag strip, there are way better combos for the money.

If you want a cool street car that has good HP, and awesome torque, really fun to drive power - this is the set up - if you don't plan on tuning it - don't buy this set up- you'll be disappointed for sure.

 

How does the tuning effect fuel mileage? Ballpark avg?

 

Well if you tune for at WOT, it may not be great for everyday, but if you tune for everyday driving, it may work well.

But in general, if you tune it reasonably, it should see better mileage, more power, less throttle you use, the less gas. Just depends on how 'raced out' you go with it.

 

I consistently get 14mpg which sucks here in CA with gas at $3.00 a gallon. There may be another mpg or two in tuning and possibly I have a problem with my EVAP set up, or even a sticking egr. If I could get 16~17mpg I would be very happy. even when I bought it back in 1990 it only got 16mpg stock, and with the vortec combo before it was tuned and with the ARAP bin I would get 17mpg on 90% highway mileage 15 arround town. the hotcam is not very efficient at low rpms. once tuned now it gets arround 15mpg on 90% highway, but my BLMs are off at high speed cruise, maybe 118 should be that magic 128 I could be giving up my 2+ mpg there.

DOn't get me wrong though, the car has way more power with the custom tune over the ARAP bin - no comparison. With a slightly smaller cam, or a stock cam with a good tune the milage would be way better, and my torque converter doesn't help arround town either,

 

My setup is in my sig .... I made 251 rwhp (with a stock AYPS 305 prom ) . So my cam is smaller than the hotcam ....but wasnt THATS far off it seams . It was also on a 95 + day when I dyno'd . Either I did good ....or that vortech setup was lacknig at the time ( I know mine was for sure )

 

I almost want to approach SDPC on they're HP claims. According to most of the guys posts here, it doesn't seem like the claim of 300 hp with the addition of the vortec head kit alone will fly. I'm not saying I don't think they're kit has some nice parts in it, I'm just saying don't tell me my motor will make those #'s when the reality appears that you need to do (and spend!) alot more to attain them! Kind of a little false advertising.

 

my car pulls over 100 MPH in the 1/4 mile

103 is best but consistent 101

Stock Vortec heads, Stock SDPC base, Stock runners and plenum, stock cam, Edelbrock TES headers, no cat and Dynomax Cat back.

My car weighs 3570 without driver

All HP calculators put my car at 280-290 rwhp...so I think 357 CHP with a HotCam is very possible, thus SDPC claims seem to be on the mark.

My .02$

 

I could also pull 101-102 trap speeds from my hotcammed vortec 350. Their claims are close for a 350 being tested on a stand(which is how they tested it:-)).

Vortec heads and base compared to stock heads and base is not even a comparison. I would love to see someone who just did heads and base to see what they got. Prolly and honest extra 40-50hp as claimed.

U could do the same thing going nutso on a stock base and porting the poop out of it(u can get lots of metal out of one, I have done it) and port the stock heads and go thru them and be almost at the same range.

That gets trumped by the vortec heads are avaialble for less than what it would cost u to go thru a seat of stock heads competenelty.

Course the vortec have the far better combustion chamber design and make equal power with less timing and yadda yadda.

Depends on the budget, but if all else is equal I always go for a more modern cyl head design, no matter what the appplication.

just rambling
JEremy

 

Interesting #'s. How much converter and how much gear are you guys running. Also are you running in street trim with those MPH's. Very impressed for a stock cam and plenum/runners! Did you have to modify the 'puter at all to get those #'s?

 

I am running an stock torque converter and stock 3.23 gears. Tuning was needed to maximise the setup. Before tuning car was running 97-98 mph at low 14s. Now runs 13.6-13.7 at 101 in pure street trim, drive to the track and line up. Best run on a strong backwind has been 13.34@103 on worn out BFG Drag radials.

Before Vortec heads and SDPC lower car ran best of 14.6@94mph after tuning.

Car started at 15@89 MPH in pure stock condition. Exhaust and tuning netted the above 14.6, then came the heads. Heads are bone stock aside from springs.

I full second and a half plus 10-12 mph gain over stock is rather impressive IMO. All this while retaining all street functions and even better driveability over stock. Also nets 25 mpg on the highway!

A 6speed will really make the car quicker too, that's a possibility for the future.

 

Have you thought about loosening up the converter? That combination is pretty much what I was looking at running. I impressed that the drivability is still excellent and gas mileage is still good! Who did your tuning? Did they change alot?

 

My brother was running a looser tc and IMO i prefer maintaining the stock feel versus a 10th or 2 in 1/4

I did my own tuning. Got into DIY prom burning 3 years ago thanks to this board. Bought EPROM programmer, built ALDL interface and bought a WB O2 sensor and controller.

Its a steep learning curve, but once you get into it the rewards are worth it.

 

my experience, but......

i have the scroggin engine and am pretty happy with it. the magazine artcile is why i bought the engine. they used a stock chip, stock TB, stock injectors, zero gasket matching, and stock plenum. i know because i spoke with brian on several occasions.
to me, that said a lot of HP was left on the table.

it doesn't even begin to address what effect a HSR or other after market intake would do to let this breath. look how low the torque and hp numbers were arrived at.

brian told me he was running 1.8 60ft times and 13.5 at elevaton. he was claiming corrected times in the mid 12s. not verifying the info just relaying it.

now as for mine i did the chip, ported the plenum, gutted the cat and did the gasket match along with a few other minor items. she runs just fine. ask my buddy with the audi s4 i just smoked last week. after he nailed it first i drove past him and was pulling away. that car is listed as 0-60 in mid 5s quarted in about 13.6 and i was driving away from him. keep in mind i still have the sucky 2.73s in it.

i guess i am trying to say it ain't bad bang for the buck. no doubt you can get better stuff. we all know fast=$ so how fast can you afford to go?

just my

 

I have stock 3.23's and a 2200stall act converter from pro-built, and the car is tuned, I just have the milage problem I mentioned. From a stoplight I have pulled most all stock things. And believe me here in San Diego every magazine "car of the moment" is out here, and you will run into all of them on occasion. you name it, people have them on the steets here. To be honest the new 300Z's are really pretty fast ( must be the gearing or something?)

But as we all seem to agree who have this combo - it is a significant improvement over stock, and brings the car to horsepower levels of modern cars, plus torque they can only dream of. all for in the real world a pretty fair price for what you get... this is not a cheap hobby - unless you're into nitrous, cutout's and gutted cats, (cheap horsepower)all which don't fly to
well with the smog police, or the longevity of a high mileage l98,lb9, etc...


210rwhp to 290rwhp is a real 100flywheel hp gain, that's not a joke. IMHO you NEED better brakes because the car is that much faster over stock, my car accelerates way harder than it ever did with a stock bolt on L98 - there is no comparison

can you get more HP for the same money - probably choosing the combo wisely- and pass CA smog - probably not

$.03