83 Crossfire TA

iTrader: (2)

I suppose that this question could fit in boards on this site, but I really want an answer WRT to power adder, which you guys think will work best for a turbocharged small block/which I should use (I don't want this to be a discussion about the engine, but it's going on a 305 with worked/modified LT1 heads and a big cam for a 305 or turbo setup).

I have 4 manifolds that I could use, 2, maybe 3 that I'm willing to use:

• Modified Victor Jr (2975)- it was already pretty heavily worked when I picked it up (had a "ross" badge screwed to it, really looked like some nice work), I added injector bungs and did a little more cleanup (it looks fairly ratty in the pics, but that's because it's covered in sawdust and had half the paint stripped off it)
• Accel Pro Ram- I've heard good and bad things about these things. Its in really good shape, looks good, but has some rough port work that I would clean up before using. Surprisingly, it's taller than the victor
• Modified LT1- I suspect that this one may be the least work to use but will rank second or 3rd on how well it will work. I expect it to flow a little less than the accel but may not have as even a distribution as the other 2.
• stock TPI- don't want to use it. It might be a good choice (modified), but I don't feel like dealing with it, I hate the number of gaskets and bolts you have to mess with to do anything with the fuel system

With the first 2 I have a few choices WRT to TB, I have a precision elbow and 90mm TB, I have an Accel 4bbl 1000cfm TB, and I have a 58mm tpi/LT1 style TB that I could make an elbow for (probably use that on the LT1 if I used that)


I've uploaded a couple of pictures of the Victor Jr and the Accel, the victor jr is the darker one in all the pics

Drac0nic

Skip the GM stuff IMO, go with either of the first two. Honestly some people will tell you that it will "lose torque" or something like that, but it shouldn't make as much difference as they say. See article below.

The question to me is ultimately runner area and how they match up with your heads. I'd go with the intake that matches with the port roof the best, the highest floor and otherwise if worse came to worse probably the one with the most plenum area. I'd probably go with the smaller CSA of the two, even though it's going to be an aggressive engine (Could see 300+HP with the right cam IMO if you have the nuts to rev it to get there) there are still limits turning at a sane RPM.

http://www.carcraft.com/techarticles...d/viewall.html

TwinTurboROC

Depends on what your goal is, Vic jr has good power up top, but if its a 305 i assume your rpm ceiling is 6k or less. Accel and LT1 are just bleh in my opinion.

Now the modified TPI setups. AKA Mass porting and using siamased runners work exceptionally well. Add to that that shift points on a 700r put you right back in the power band of most turbos (im gonna assume your in the 60-76 mm range).

Any more specs on what your doing if your gonna tell?

What kinda powerband you looking for?
What kinda use is this? Track? Street? or the OTHER street?

83 Crossfire TA

iTrader: (2)

LT1 heads ported to felpro 1205's with about as much bowl, below the seat and throat work as you can realistically get away with with stock valve sizes (didn't want to go bigger for the 305 bore). They really should flow rather nicely.

Probably an XFI 280 cam (230/236/113)

Sounds like you're leaving me with the vic jr

I think that the TPI, especially dressed up is one of the best looking intakes out there for an SBC, but I _hate_ working on it. If I did it I'd probably do something to keep it looking totally stock... but I don't see it happening.

700 won't live behind that thing, I'm figuring a 400 or 4L80e (I have one sitting around that I've been avoiding putting in something, have a PI 3600 stall with 3 disk clutch for it too, though I'm wondering if I should be shooting for something closer to 4000 stall), currently manual tranny, I suppose may stay that way for a while.

What's the "OTHER street?" use- yea pretty much all of that, but I'll let the rest suffer for good track times.

TwinTurboROC

Well the other street use is the "grudge" street use if you get my drift. The TPI system is awesome when paired with a large turbo, small exhaust ar combo. That teamed up with the 700s shifting point makes for some fun times.

On another note 700s can withstand a shitload of abuse when built right. If you get a chance look into CPT performance. Frank from cpt has some retarted fast car using his tranys. From what i gather from the lt1 guys its as good as ProBuilts uber trans.

BUT... if you have a 4l80, DO IT.

What are you using to control it btw, the TCI unit? Or one of the other oddities?

The Vic jr is a great "race intake" as most of it worthy power band is from 3k up (especially if your gonna be using a 305, keep that in mind). Im talking usable grunt of the powerband. If your not screaming to 6500 to 7k range i would not bother with the Vic, but it will make the difference at the track if you gear the car for 1/4 runs.

I like the TPI. Its a great intake. It should have been put on a truck. That being aside, its got great potential when boosted. You got to get the siam runner and port the **** out it though. If you can squeeze 5800 RPMS plus or minus 100 before you loose 10% of your peak HP with the TPI its worth it if you have the parts on hand. (and most of the dyno numbers i have seen, and heard of put the extreme tpi port siam combos right around there).

Have you considered the stealth ram? (or are you just deciding on what you have on hand in your garage) I have on on my black iroc and its just...well...awesome. I will never put another intake on any SBC other than that, unless i make a fab intake myself.

What is your engines RPM safe limit?
3500 stall is plenty. you should be able to flash it a bit higher at the track. (But i guess youll have to wait till its in the car to figure out what its exactly doing)

project89

iTrader: (1)

use the tpi and do what im doing with a spare unit i have.
cut the runner tubes off above the top of the fuel rail and make flanges that weld to the runners.
from there u have the perfect base to bolt down a custom plenum to.
this will shorten the runners considerably and would help the thing move some air above 5,500 rpms

Orr89RocZ

iTrader: (20)

I've seen a 383 or 396 supercharged LT1 car pickup alot of useable hp/tq across the entire rpm range when going to a ported victor EFI type intake over a ported LT1 factory casting.... Not sure if the 305 will benefit as much but the single plane is a good choice for boost. It sees better air distribution if the elbow is done right. He reported better air distribution according to the plugs. I've been real happy with mine so far, all cylinders look good. But I'm 400" and no idea how a small motor will take the single plane EFI setup. I dont think it will be much of a problem with that 280 cam. It wont have much low end to begin with no matter what intake you use, it will want to rev up and need boost to make it come alive.

Drac0nic

After seeing your cam choice TPI is way out. That would be a gross mismatch to say the least in where power is going to come on. Single plane all the way.

TwinTurboROC

Not really drac, that cam should start rolling power from about 2k on. Its a gross mismatch the other way too. The XFI 29X (w/e number they have) is a better choice for the vic jr. Only thing i would be worried about is 1st gear and comming out the hole. But if you got a big enough converter shouldnt be a problem. TPI will make HP there. Its just squeezing the last 500 rpms out of it by cutting out and porting **** if he goes TPI.

With the Victor jr, hes kinda loosing the 1000 rpms is down low before that manifold/cam range starts ramping. But up top its gonna scream. (A stock 305 should NOT be reved passed 6k rpms if you want any usable life out of it)

Its like being stuck between a rock and a hard place. Truthfuly the Vic jr, will be the better track oriented if you gear it for the 1/4 only.

Orr89RocZ

iTrader: (20)

280 xfi works best with 3600-4200 stall converters in a 350" motor. Peak powers are generally 6200-6400 rpm and power holds to 6500-6600 well if the heads arent restricted. Its a big cam for a 305 and would be a good match for the vic jr type intakes since you will be optimal in the mid 6000 rpm range. If you arent revving it past 6K you are leaving alot on the table for power with that cam.

LT1 intake isnt any better as its short runner design will lose more torque compared to the single planes. With EFI the single plane isnt going to hurt bottom end as much as it does in a carb car. Carb relies on vacuum signal from motor to feed fueling, and low airspeeds from big cams can make things sluggish but with controlled fuel delivery from EFI, it balances out. My 401 at low comp with small heads/cam felt torquey with single plane, even with 2.73 gears

junkcltr

iTrader: (1)

Victor JR
228/228/112 cam

Drac0nic

I concur with this very much. I think ARP bolts in the bottom end if you're feeling rich a balancing are going to be good ideas. I'd think you'd be going nearer to 7K than 6 with this combo, and no way would I leave it at 5800. Based on what I've been reading I was planning on revving to 6500 or so with a 219/226@.050 cam or something thereabouts. I mean, think about it this way. A basic set of stock Vortecs flows around 226 CFM on the intake, say 220 CFM with 1.92 valves due to bore shrouding. 220*350/305=252.5CFM. So even a set of basic Vortecs would flow the equivalent of a head that flowed 250 CFM on a 350. Mark is making the right choice with a larger cam to match this, and a larger intake in turn to match the high RPM potential of it. Afterall, if you had a 250+ CFM head on a 350 how high would you spin it?

If you look at the Car Craft article I posted, even with a Performer RPM versus the Vic using a carb the power's within a few HP even as low as 2500 RPM. Yeah a TPI would probably make a bit more power but is the cost really worth it, especially since I think he's going to be running a largish turbo that's going to take some revs to spool and with a high stall. By running a higher stall with a TPI it would likely limit the usable power band. Depending on the converter's stall it could actually make it so you're out of power by the time you're shifting. Worse case scenario, but possible. Especially with a box like a 700R4 where the RPM drop is worse from 1-2.

I feel confident in saying that yeah a few ft-lb of low RPM torque may look good but I doubt you'd find someone at the track running better times with a TPI and that cam.

83 Crossfire TA

iTrader: (2)

Sorry for disappearing from my own thread, infant twins will do that to you. They're almost 2 now and I've been driving this thing as a nearly stock '87 TA while slowely accumulating parts and occasionally working on things.

I'd like to add 2 more manifolds into the ring (and after that I'll answer some of the questions and add further comments):

• Victor E- I picked this up from a list member, mostly for the stuff that came with it, but this thing is pretty much a modern version of the victor jr that I ported. Looks like the casting is slighly better geometry than the victor jr, but doesn't have the nice porting that the jr has. I took some pics of the 2 next to each other and its suprising how similar what edelbrock came up with is to what I did on my own...
• Performer RPM Airgap- another good deal on a used part... I'm really kind of liking the idea of converting this one to FI... yea, no one does it, but I don't see why. The port cross section is very close to the vic jr/about the same as the vic E, but with longer runners. The coolant crossover layout is actually slightly better for my use with the converted LT1 heads, and suprisingly, this thing is 8# lighter than the lightes of the other manifolds (well, actually, I don't know what the TPI weighs, but I'm not sure I'm seriously considering it either). I've turned some injector bungs for it on the lathe and I've very tempted to drop this on the bridgport and plunge some holes for the bungs in it. The bungs are more than tall enough to compensate for the differences in runner heights, which if I get them really close to the flange shouldn't be that great anyway.

Anyone have any thought about either of these vs the others already listed (honestly, the TPI will be too much work and parts that I don't want to mess with to work well for this project, and if I want the look I've machined a TPI plenum for a 4bbl flange so I can use it as an "elbow" on top of one of the other manifolds, and the Accel just doesn't give me a warm and fuzzy... so they're probably out of contention).

83 Crossfire TA

iTrader: (2)

why the tight LSA? What lobes? Is this an off the shelf cam? That's actually right in between the 2 cams that I have sitting around that I've considered for this... I have a custom xe lobed 224/224/114 cam and the xfi 280. Honestly, the .050 specs for the xfi 280 sounds a little too healthy for this deal, but the advertised 280/288 does not sound that big. The part that worries me more about that cam is the .57x lift with 1.94/1.50" valves in a 305...

Really, the biggest thing that makes me nervous about the xfi cam is the stock short blocks (I have more than one), and I suspect that I'll have to wing it up to close to 7K rpm to really use it. If I convince myself that that's crazy then I may run the 224/224/114 or get something in between (thoughts? suggestions?). OTOH, I've winged a stock LT1 long block up to 6600rpm spraying it with a progressive 250hp shot and never broke it (gears, axles, clutches... broke all the time though), and smoother pressure delivery of a boosted setup shoulld tolerate RPM better (yea, the '97 rods and probably the hardware are better pieces than the '87 stuff... I know).

83 Crossfire TA

iTrader: (2)

FWIW, the LT1 heads are welded, ported, milled (rigged something up to do it on the bridgeport )... I hope to get them flowed soon, but I expect something in the 250-260cfm range on the intake (based on others I've done), and I worked the exhausts harder. If they don't flow what I want them to I can imagine some work around the valve guides that I can do to get a little more flow.

Honestly, a 305 doesn't need that kind of port flow to make power up to 7000rpm (I'm pretty sure the stock ports will feed a 305 to 7K), so I'm not sure why I'm spending time doing this besides that I can, so I can say I did and it's just some extra cake when I start forcing air through them.

83 Crossfire TA

iTrader: (2)

So, everyone disappeared?

Orr89RocZ

iTrader: (20)

I like the vic E but it is a big intake, likely better suited to bigger engines but should still work good. I really think the 280xfi is too big for a 305 without a big of head work and revving 7000 rpm. That would scare me on stockish bottoms. 268xfi would be abit more friendly