Flfinn

(Tried to search for earlier posts, didn't find any.)

So is it worth changing the cam for 305TPI/T5/3.42 posi? Other mods are on my sig.

Later on I'm going to get headers with cat back. I know I could get quite radical with the Haltech..

I'm hoping to get 40-50hp without loosing my low end torque (with the headers/cat back) And I've heard that original runners/baseplate will flow enough with mild mods on a 305.

I was thinking on Cranes compucam 2031. Rpm range 1500-5000, adv dur in264 ex270, 112 lobe, lift in .438 ex .452
Is this too much of a cam? Or what do you guys suggest?


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-88 GTA 305TPI/T5, 3.45 posi, minor mods (slightly ported+portmatched heads, base, plenum, multiangle valve job), Haltech E6GM, ~more to come. ET 15.2@93mph. www.helsinki.fi/~kjilehto

Kevin91Z

iTrader: (1)

What is the @.050 duration for that cam? The lift seems kinda small. For a 305 I'd get something in the 206-212 intake duration range, with .480 or less lift, if you dont want to change the valve springs.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

'87FAKE-IROC-Z

i've heard good things about comp cams 08-302-8, i'm going to use this in my 305 tpi.
with your five speed you could go for a little higher power band.
anyway the specs on my cam are
dur. intake 210 at .050 lift
dur. exhaust 220 at .050 lift
lift .480 intake and .480 exhaust.
lobe separation 112 degrees.
just my opinion on a good cam.
this cam i think has a 1500-5500 powerband.

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88 CAMARO RS
87 IROC-Z DRIVETRAIN
305 TPI, 700R4, 3.73s
ported plenum, performance resource chip,edelbrock TES Headers and cat-back, K&Ns, AFPR, rest is stock.
15.0 @ 92.5 (bald tires)

355 IROC-Z

the cam 87 fake suggested is about as big as you should go. anymore then that would be a waste of money, and power. the slp 51002 (believe that is the grind #, i know 002 is the last part) would probably be ideal for a 305 IMO. with a T5, and 3.45 rear, you can probably run alittle more duration then with an auto. what is the centerline of the cam? if ya want to keep the low end, i would try for 106-108 in. centerline. you might have to adv. your cam to get that centerline, but that isn't hard with offset bushings.

of course, if you really want to complement your combination, i would suggest porting the plenum out and radius blending the runners, this helps the topend breathing considerably.

hope this helps

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87 iroc-z 355 TPI 5 spd. 51006 SLP cam adv. 4* (106.5* centerline)
hypertech stage II chip/ 160* stat./ Airfoil, accel AFPR
19# injectors, ported plenum and runners. 9.8:1 compression
stock heads, pocket ported, 1.94 int., unshrouded.
stock exhaust manifolds and y pipe! hopefully soon to change
3.45 rear (stock)
Flowmaster, K&N w/ hacked airbox/removed MAF screens
14.38@100mph 2.2 60'

ViciousZ

iTrader: (1)

I 've got a 305 TPI with edelbrock TES, 2500 stall, and 3.73 gears, to name the major mods. I put in SLP .480 .487 lift 206 212 duration and I went slower! I lost a tenth and 1 mph in the 1/4. I can't figure what went wrong because I thought that cam would be perfect...

88IROCs

1. this is probably a silly question to ask but,... you did upgrade the valvesprings when you put in the SLP cam, right? if not, I can think of about 3 or 4 reasons why you lost power and why you should replace the stock springs right away.
2. you're gonna hate me for mentioning this but,... CompCams has two cams that are duplicates of the SLP TPI cams. But the CompCams versions cost about $100 less(enough to get some real good valvesprings). XR258HR-10(p/n 08-408-8) matches the SLP little cam(206/212 dur @ 0.050, .480/.487 lift, 110 LSA). XR254HR-10(p/n 08-412-8) matches SLP's big cam(212/218 dur @ 0.050, .487/.495 lift 110 LSA).
3. if I remember correctly(which is a bit of a challenge lately), the stock 305 head intake port stalls at around 0.450" lift, above that excessive turbulence actually causes flow to decrease. If the cam is spending an appreciable amount of time above 0.450"(which I believe is the case with the cams mentioned) you may be restricting flow into the cylinder. you could try cleaning up the runners and doing some bowl work. Or you could look for a cheap set of Vette heads or maybe used 305 Torquers.
4. then again,... mebbe the ECM just needs to know about the extra air the cam is allowing into the engine(read you may need a new prom).

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He who hesitates,... is lost!

355 IROC-Z

you are usually ok with coil bind and guide to retainer clearance up too .500 lift i have found. this is no excuse, though, cause if you reused the old springs (which i would strongly recommend against) they are probably weakened to the point where there isn't enough tension holding the valve closed and they are bouncing off the seats when they close. you can get away with getting brand new stock springs (for that lift) for $35 (i have been guilty of this too), but would you should really get springs to go with your cam. looks like you had the right idea with gearing and TC.
i have to agree with 88 iroc %100 with the flow rates of the stock 305 head. an unmolested stock 305 head can't flow past .450 lift, atleast anything to get excited about. i did notice that flfinn has some port work and port matched heads in his sign. i believe with porting the plenum out and radius blending the runners, a cam with .480 lift and about 210-215 dur @.050 would be advantagous.

Flfinn

http://www.cranecams.com/master/apps/chevy37.htm

There's the site I found that cam I was thinkin of. Duration at 0.050" lift is int. 208deg. exh. 214deg. I belive it's the most wildest cam crane has to offer me, at least on their website.

Thanks for all the answers. I'm still wondering how much hp/torque I would possibly get with it? I'm hoping a real good boost compared to the stock roller..

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-88 GTA 305TPI/T5, 3.45 posi, minor mods (slightly ported+portmatched heads, base, plenum, multiangle valve job), Haltech E6GM, ~more to come. ET 15.2@93mph. www.helsinki.fi/~kjilehto

[This message has been edited by Flfinn (edited November 23, 2000).]