I'm thinking about swapping cams when I install my TPI setup, what should I get?

Goodwrench350, Stock (ported) TPI (SD), custom chip, full MSD ingition, Hedman shortys, 3" cat back (no muffler),AFPR, 2400-2600stall non-LU converter, TH350, 3.42 open (gotta get a posi!).

I'm running a Performer RPM intake and a Holley 600 now and it's got a TON of low end torque, but it falls flat on it's face after 4800RPM.

I know the heads SUCK (8.5-1 CR, small ports), but I'm not allowed to swap them until the warranty is over (aren't parents great?).

I'm looking for a hydraulic roller.

Thanks,

John

 

are you going to run the stock TPI setup? if so dont expext it to pull alot more than the intake you have on there now.

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Brandon
"ScreaminDeamin 360"
350 60 over, TRW forged 9.83:1 pistons, crane cam 216/228 .484/.512, crane 1.6 RR's, ported plenum, home made ram air, 19 lb SVO injectors, crane AFPR

 

Quote from TPIS: " ZZ-X camshaft- Would you believe 408HP, 451ft/lb. 350 with factory tuned port, a stock, throttle body, and only an airfoil- and it pulls to 6300 RPM."

Even if most of the power is in the heads, the intake still has to FLOW that much air.

 

Don't believe everything you see or hear. TPIS might have good parts and all but they are just like every other manufacturer who claims their spark plugs give you 25HP, their headers will give you about 125HP and let's not forget those magic fluids like Prolong and MotorUp; you put one of these babies in your car and you'll be running 11s for sure

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'88 GTA 350
Headers, catback, free mods, Xtreme energy cam, and intake pieces
13.51@104.27, but can run better as it is.

I just put a new 2100-2300 RPM TQ Converter. I hope a 13.20 or better

RAPTOR, the baddest bird on the planet
AIM HIGH!

 

LMAO! I know, but still, ANY aftermarket cam MUST be better than the stock cam in this motor!

My buddy is going to hook me up with a set of Vortecs early next year, I'm keeping an eye on the guy who is trying to get his TPI lower to match up, I'm hoping it's something I can do in my machining class, if so I'll be running Vortecs soon. And I KNOW the stock cam will be choking it BIGTIME!

 

whatever man. you do what you want to. we know nothing! good luck

------------------
Brandon
"ScreaminDeamin 360"
350 60 over, TRW forged 9.83:1 pistons, crane cam 216/228 .484/.512, crane 1.6 RR's, ported plenum, home made ram air, 19 lb SVO injectors, crane AFPR

 

I HOPE you are not seriously considering adding the TPIS ZZ-X cam into a stock L98?

If you read TPIS' FAQs they discuss someone wanting to add a ZZ-X cam and they state how it is an "ON/OFF" cam. By that it, you either are ON the gas and accelerating or OFF the gas...no in between. It is designed solely for racing where you are on the gas for the race...that's what is designed for.

TPI requires matching the cam to the heads and the intake. You can do the intake alone, and the heads to a fair extent. But you can't put in a honking cam without the other two. The system will run out of breath before the cam even comes into its powerband. If you read one graph from TPIS, you'll see them using the stock TPI system on a "built" 383. While the TPI does produce power at a fairly high rpm, it is no where near what other systems are producing because the stock TPI severely choked the system.

And lastly, depending how much duration/lift you run, you will most likely have to get a chip to attain optimum performance. There are limits again how far you can go with a cam and the stock ECM before the vacuum signal gets so low that you have to consider DFI.

Good luck machining your intake to match up to the Vortec heads. Are you aware of ALL the differences between the Vortec heads and the TPI intake?

 

I'm not saying I would run a ZZ-X, I'm just using it as an example, I'm looking for either a GMPP cam (ZZ4, hotcam, etc.) or a CompCams roller.

As far as I know the only differences between Vortec heads and L98s are the bolt pattern (8 bolt instead of 12) and the ports (High port- LOTS of cutting/welding). I know you can drill the heads for the standard bolt pattern, or the intake for the Vortec pattern, but the ports are supposed to be pretty far off (even with the "special" gasket).

 

I'm going to be burning my own chips also.

 

Check out Comp Cams XR270HR-10 part# 08-422-8.

Duration @ .050 218I/224E, lift w/1.5 .495I/.502E. 110 LSA.

I think you'll have to change the springs on the Vortec heads with that cam (or at least should). Comp Cams recommend spring #986-16.

That cam will like some compression and prefer a different intake than the stock TPI to get its true potential. If you really are sold on keeping the TPI system, I would recommend a shorter duration and slightly shorter lift.

Also, you REALLY need to change the "peg-leg" in the rear for a good posi.

[This message has been edited by Glenn91L98GTA (edited November 14, 2000).]

 

Double...

[This message has been edited by Blade (edited November 15, 2000).]

 

Glenn I'm running that cam in mine after someone recommended it to me (maybe you?). I'm not too happy with the performance so far. Maybe I need a different intake :/

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92 Z28 L98 350
---------------
Ported and polished heads, ported stock TPI base, ported plenum, Comp Cams XR270HR-10 cam (lift .495/.502 duration 218/224 lobe separation 110), Edelbrock TES headers, LT4 valve springs, Crane AFPR, Flowmaster catback with LT1 style tips, MSD coil & wires.

Best ET 13.5@105 mph

"Take that auto, drop it in first, hold the brakes, stomp the gas and grin from ear to ear! :-)

http://www.truspeed.dhs.org/Members/...dmondIndre.htm

 

I very seldom recommend cams. But as I said, it is best matched with something other than the TPI system (and preferrably heads). I notice you only have a ported base and ported plenum and I think you need a better flowing intake to take advantage of the top end of the cam.

Also, have you looked at your chip? I don't see any mention of whether you are running a custom PROM or not.

I noticed your your times and trap speed. Based on your mods, your et's are not too bad and your trap speed is quite high. If this is NOT a G-Tech time, that would indicate the top-end power of the cam really kicking in. What were your 60' times?

Also, if you don't have a higher stall convertor, I would definitely look at that. Also, what gears do you have?

 

Well let's see.. that IS a G-Tech time with almost perfect traction (on the street). Dunno what the 60 foot is, but 0 to 60 mph is reached in 5.3 seconds. The trap is high cose it's the g-tech... so track mph will probably be 99-100 mph. ET should definately be lower since I can hook like mad at the track! Gears... stock 3:23s, stall... stock vette 2200 stall. Yes I'm running a custom PROM designed by yours truly. I still have a little more tuning to do to squeeze another tenth or so. The stock baseplate is just port matched to the heads. I kinda ****ed up on the porting (the walls on the intake port are bigger then the heads so that sort of kills airflow... so I'm looking for a different intake to start over with.
------------------
92 Z28 L98 350
---------------
Ported and polished heads, ported stock TPI base, ported plenum, Comp Cams XR270HR-10 cam (lift .495/.502 duration 218/224 lobe separation 110), Edelbrock TES headers, LT4 valve springs, Crane AFPR, Flowmaster catback with LT1 style tips, MSD coil & wires.

Best ET 13.5@105 mph

"Take that auto, drop it in first, hold the brakes, stomp the gas and grin from ear to ear! :-)

http://www.truspeed.dhs.org/Members/...dmondIndre.htm

[This message has been edited by Blade (edited November 15, 2000).]

 

I don't know if the stock Vette TC is quite that high, but 2,200 rpm is still on the low side. I would have thought around 2,600 rpm with that cam, with a good TC, like a PI Vigilante.