Abubaca

iTrader: (3)

If by myth you mean compared back to back with the other manifolds on a flow bench then yeah, it's a myth.

Look, you guys are missing the point. ...and for the record, I'm actually looking into the Vortech TPI myself. ...but I have some specific goals and reasons for doing so. But let's take a basic build up. Vortech heads. Awesome. But they'll need work to accomodate even an average sized cam. I think it's only capable of around .480 outta the box? Not sure exactly. So by the time you do that, they're about the same cost as a good aluminum head. Not $1500 dollar AFRs, but right around the $1000 dollar mark. But you can argue that the 170 intake runner and chamber design is still worth it. I'll go along with that, no problem. Then you figure an aftermarket TPI intake, vortech or not is between 4 and 5 hundred. OK that's fine, but as has been TESTED time and time again, the vortech flows better than stock by a little, but is nowhere near the next best aftermarket intake. Soooooo, again, as in so many other areas, it'll perform great, but dollar for dollar, not AS GREAT as another option. I love TPI, I love Vortech, I love T5's and Borg warner rears. ALL good parts, but ALL proven again and again to be good, but not AS GOOD as other parts available.

...and SDPC got those numbers with a ported intake, long tubes and a big cam, on a motor that most certainly was tuned and timed to put up as peak of an HP number as possible. ...and of course it was at the crank. But again, because I know you guys will nit pick, yes, those are certainly respectable numbers. I would be happy to make them with my motor. ....you what's ironic, if they'd used a smaller cam and shorties, they'd probably get a MUCH better looking torque curve, which would be more appealing to the hot rodder, but of course, the masses want that peak HP, which in all reality doesn't tell much about what the car/motor is really capable of.

Rolling Thunder

Well the thing is its not that the vortec base is terrible from the flow data ive seen its about as good as the stock piece but it is no myth that it is not as good in terms of flow as the standard tpi base equivalent. Now you have noticed that vortec TPI motors do pretty well and that is also true but its not because the base is good its just that the heads make up for the bases short comings. The reason is that although the max flow of the heads would be limited by the intake all the lower lifts that arnt limited by the intake flow better too. So when you take into account the cam profile with respect to these flow rates at different valve lifts you can see how the vortec set up's net flow would out do the standards l98 heads for example by a pretty decent margin. So it would make a big difference swapping to a vortec set up and nothing else because even though the base is about even with the stock piece the heads flow rates allow you to have a larger net air flow for a given cam profile over say stock l98 stuff. However with an appropriately chosen cam and good heads like afr 180s or even well worked l98s the tides start to go back in the classic sbc set up's favor. So really you could make an argument to go either way. If you were stuck using a flat tappet cam you may not be able to have the ramp rates that would allow you to really take advantage of the higher max flow rates so the vortecs with their superior flow on the lower lifts may out weight the benefit of a larger max flow. So its really a judgment call depending on the application but overall, with no restriction as to parts I could chose from, I tend to favor standard SBC heads with a good base.

Abubaca

iTrader: (3)

That's an awesome point too. Part of why the old school guys love 'em. Flat tappet cams. Also-The vortecs also tend to fall off exponentially after .500" (even with non TPI) lift. While I don't know exactly why, my guess would be that it's the small runner size, which is part of what makes them great UNDER the curve. You know what would be interesting. An off the shelf head, SDPC mani, stock runners and stock cam. That would be neat.

RED86Z28

How does stock like flow equal terrible? I could understand the criticism if it flowed worse than the original gm casting. For $399 it allows you to use inexpensive heads that make a big difference over the original castings. You have to look at the overall package sometimes instead of the individual pieces.

Orr89RocZ

iTrader: (20)

Well compared to other regular TPI manifolds, for the same price, you can get MORE potential out of the regular style TPI manifolds. Ported/welded up aftermarket bases can flow 300cfm to match the best of best heads out there. Vortec bases are MUCH more difficult to work with and I do not think they can hit 300cfm. High 200's maybe. Its been proven by the california guys that post here. They have taken TPI setups to levels beyond most.

But your typical budget setups you can do well with vortec TPI. I havent seen a Vortec TPI setup with stock vortec heads dyno numbers, but I do note that mild cleaned up 113 L98 heads with aftermarket base/runners can easily do 320whp. Its been done by quite a few members I do believe. Would make more power with HSR/miniram/etc.

Bolt ons. Doesnt really matter if its all aftermarket TPI, HSR, or miniram. You do exhaust/headers/some kind of intake manifold, give it 8-10 deg base timing instead of 6, throw in 93 octane, and 2800 stall with drag radials, you will be mid low 13's on a good day. 235-250whp/315-380 wtq depending on the manifold you go with.

I'd really go with 1.6 rockers and a tune while your at it. Makes a big difference on the shorter runner intakes.

I had these mods and went 12.95 at 103.8 mph on my full weight 89 Irocz:
Stealth ram intake, gutted TPI air box, custom tune by me with more timing in spots, 1.6 rockers, hooker 2055 headers, custom 3" catback, 2800 stall, 3.42 gears, drag wheels with slicks/skinnies up front, new injectors since my old ones were bad, full suspension mods.
It made 254whp running pretty lean and 315wtq with flat curve. Shift by 5500 rpm. Car hauled for bolt on L98. Very fun.


With just stock TPI, hooker 2055 heads/flowmaster catback 3", 3.27 gears, stock Irocz wheels with drag tires on back, 2800 stall, full suspension, it went 13.63 at 97 mph in good air.

As you can see intake mods/1.6 rockers makes a BIG difference in ET compared to stock TPI

IF you can get a L98 in the 13's with bolt ons something is WRONG!

The key is suspension, drag tires, and 2600-3000 stall. A good designed converter that will hit tires pretty hard. Get 60 fts down in the low 1.7 range.

My buddies 88 formula 350: 13.59 at 99 mph on street tires!! Mods: Vette L98 swap: bigmouth runners/aftermarket base, 52mm TB, 113 heads with mild clean up i think it was, chip tune, shorty headers, custom exhaust 3", 3.70 gears. STOCK transmission/stock converter. ON 16x8 street tires. 1.93 60 foot. 90% of his runs were in the 13.6-13.7 range. My car when it was doing 13.63 with bolt ons/stall above, ran 13.8-13.9's on street tires. Low mid 1.9 60 foots.

Rolling Thunder

Yea I really love vortecs for the vast majority of applications. Not only are their flow rates pretty outstanding for what they are but it does so with a relatively small port size for superior air velocities over comparable flowing standard 23 degree heads. However unfortunately nothing is black and white and although vortecs are great in many applications the standard sbc heads still have their place this application I believe being one of them.

Well If you wanted to run a pretty much stock l98 but with vortec heads I imagine it would make a pretty decent difference. The L98 cam isnt too crazy so you would get a bit of benefits from the superior lower lift flow rates as well as it would help exact more flow out of the fairly restrictive stock TPI intake. The benifits would be more pronounced than swapping to comparable standard 23 degree aftermarket heads. All and all I think people would be surprised and would be a great learning experience to demonstrate some basic principals to consider when building motors for example just how much max flow numbers mean on their own as well as some of the effects of different cam profiles. I think it would really show why parts need to be matched to work with each other for maximum effect. Probably not a build I would do given the choice but if I was trying to demonstrate some of the fundamental concepts behind building motors I think it would be a great example of a lot of things.

1989GTATransAm

iTrader: (3)

No myth about the TPI Vortec intake manifold. It is the worst performing after market TPI intake. For the average build it will do just fine. However if you want to get into the upper echelon of TPI performance that is not the route to go.

Regarding the First TPI intake manifold. It is by far the highest flowing out of the box TPI intake manifold. Nothing else comes close. IMHO what holds it back is the runners that come with it. They need to be opened up for max performance. I bet and Extrude hone job would do wonders for it.

Anyone want to bet on a 550hp TPI motor that will pass California Smog and be fully streetable? It's not even a 383.

regal301

STOCK vortec heads make more power than STOCK l98 heads.

STOCK sdpc or edelbrock hi flow vortec base out flows the STOCK
base.

if you were looking for a high flow,high rpm setup i would not run a tpi setup or use stock heads.

a stock l31 has it all over any stock l98,its a cheap upgrade,and the low flow all torque tpi setup compliments it nicely.

ASE doc

I agree that anything we can do using what we already have will certainly save $. And Ive been quite pleased with a few TPIs Ive done using stock heads and intake components.

I fact, as far as the Vortec heads go, Im not so sure that youll do much better than with a well ported set of stockers. While I am a proponent of builing a 350 rather than a 305(more power, same cost), The 305 you already have can make great power with a decent cam and some hours of porting work.

I read on here where someone said that stock heads require machining to run higher lift cams. I have built 3 different L98s with ported stock heads and .512 lift. Only changed springs.

Orr89RocZ

iTrader: (20)

What springs did you change to? Its been said here many times that the retainers will hit the valve guide boss at .470-.480 lift. Beehive springs you can get more lift out of because of the design. I guess the retainer is thinner? I never did measure my L98 for max lift on stock castings. I wish I would have.

ASE doc

I first went to some cheap Crane springs that claimed to be okay with roller cam lift to .520. Ended up with one broken spring. Had my machinist swap in springs when he did valves. He installed Isky springs, dont know what P/N. Did not have any interference issues with valve guides.

ASE doc

BTW. Beehive springs allow more lift before coil bind because of the asymetrical design of the coil itself. For information sake, the cam I used in these TPI motors was an SLP grind(224/230 @ 050 503/512 112 LSA), as well as I can remember. I ran it with ported stock heads, ported stock base, stock runners, ported plenum, stock TB.

The cam was featured in the Summit Racing catalog during 1999 when their catalog contained a special section for TPI. It was advertised for use in "extensively modified TPI motors". And was the cam originally used in my extreme TPI project. With the combination listed in my sig, it made 450 lbft @3,500 and 417hp at 6000. I swapped it for the cam listed in my sig now to make my IROC the animal it is today.

I never dynoed one of my budget TPI builds. I would guess they made around 380-400 ftlb and probably 300+hp with stock exhaust manifolds. I believe they would have pushed an easy 350hp with headers and good exhaust. They ran like little beasts and idled sweet and lumpy. I ran them on stock programmed MAF systems with fuel pressure set at 60psi and initial timing at 12 degrees. The idle had to be mechanically set to 850.

Orr89RocZ

iTrader: (20)

The beehive point wasnt about coil bind height, it had something to do with the actual clearance between the retainer and valve guide boss. I dont remember the exact details but I remember reading many posts about situations like that, where cams over .480 were risky without machine work. The one way to gain more clearance was to shim the base of the spring up and run .050" offset locks to move the retainer up higher.

Its a case to case basis, you will have to double check your heads for max lift before bottoming out the retainer/locks on the valve guide boss. Good to hear you had luck with .512".

ASE doc

A method I learned several years ago is to install a valve with a small spring from the hardware store. Use a spring soft enough to allow the valve to be opened with hand pressure, while still holding the valve securely closed. Then, using a dial indicator, measure valve travel to the point of guide to retainer interferance. This will tell you how much actual lift you can accieve without machining. I dont remember what the stock heads allowed, its been too many years. I just remember not having to have machine work done on the original build. If my machinist, Archie Sommers, made any change to the valve guide bosses with the valve job, he didnt mention it, it's highly doubtful.

The above method for checking valve lift, is also very good for checking overlap clearance when using large cams with flat top pistons.

BigWhiteGTP

1200ft elevation but DA with our temps is usually at best 2200ft. DA that morning was around 700ft. So that helped.
The nights those LS1s were running 13.9-14.2 I was doing about the same. But that was my fastest time

T/Atime

can someone help me find a part number for this filter. i have a cheap one in the exact place. its a 3" pipe btw. or a filter that is larger or different shape.

3rd-gen's 4life

I'm a complete newbie as far as the mathematics of cfm velocity cam specs etc etc but as far as the good reviews I see from "SDPC" 350 replacement the sd360vtpi seems pretty good or the ZZ4 short block can anyone agree what the better choice might be to replace my 305 LB9 tpi and why?...pros and cons! and if the ZZ4 thinking AFR L98 heads for a little more $$. This is a second vehicle mostly driven around town for fun. I am a simple home mechanic have never built anything from scratch just want something I can swap all or most of my TPI set up with exception of injectors and ecm. thanks in advance!!

Abubaca

iTrader: (3)

Anytime "we" or anyone gets into the "what engine" or "what mods" should I do, it's always a good time. .....and it's impossible to really say what's best for you. Seriously, go search and see what the "best TPI runners" are. OMG there are so many opinions from peak power to peak torque, most metal for porting, best casting outta the box, best price, etc. etc. etc. and that's just ONE part!
My thoughts on what you mentioned are that the zz4 shortblock form GM is probably the most reliable shortblock. GM has built millions of em and you almost never hear of an issue. It's high quality, real good performance, but also very expensive. The scoggin' dickey engine also performs well, but I don't know that you might not be able to do a little better for your money. That being said, it's nice to take it out of the crate, drop it in and have a reliable performer with minimal work. If you're not planning to go crazy, I'd look into dropping in a BluePrint engine longblock, and putting the TPI on top of it. Customer service seems top notch, quality seems darn good, and the price is hard to beat.

ToolGuru

Ya know, it just kills me. Every time somebody asks about the potential of a 350 tpi, the first thing you hear is "it won't rev, it will suck in the quarter mile, it will fall flat on its face, blah, blah." We are talking about potential. So here's a post from a well respected tpi and performance guru (no offense meant to anybody here), Grumpyvette. I am starting with something better than a L98 but the plan would be the same. I've already ordered the Dart SHP 180 heads (identical to the old Pro 1's before the Platinum series came out) and putting a retro roller into it. But I digress. You will see that the plan below doesn't need a welded and highly modified intake that flows 300+ cfm. Here is the recipe. Should get in the mid 12's quite easy if I can get it to hook. I'd rather go with TPI for the street than a TBI unit from FAST, Edelbrock, and the rest of the clones. I think the OP would too, that's why he asked what he did.

http://forum.grumpysperformance.com/...p?f=55&t=10494

Good luck on the build. TPI gurus, please remember what is being asked, not everybody is looking for an all-out strip effort TPI. Keep in mind what the questions actually are and what the person is looking for.

Bigfoottpi11

+1

Bigfoottpi11

Why dont you just supercharge it?

3rd-gen's 4life

Again I'm a newbie Blue print has pretty good prices and good reviews from what I see but first off as far as the ZZ4 it has a forged crank and getting anything forged crank, rods and pistons is a good way to go from what I've researched right??? but I cant find a completely forged long block should I be going this route? I might want to get into a Saturday night spray one night in the near future and not that I have ever before but want to pop my cherry if you know what I mean but getting back to "350 potential" want to do it right once and only once! so can I ask...what are the preferred rod and piston materials to be sprayed on lol? and to give you an idea of cash flow I get $7000 with my tax return and I'm married so maybe 4,000 every year to build/purchase no rush so starting with a foundation on an engine stand as far as a short block is ok is there something like this out there complete or is the ZZ4 the only option for a rookie with a heavy foot. thank you for all your help and input.

3rd-gen's 4life

Other then maybe super charging really love the car for what it is tpi and all no forth gen seat or aftermarket hood 91-92 z28s have been my favorite cars for ever this is my 5th one in need of a restoration not to fully be original but look it so guess I'm still in the same boat between ZZ4 or 360vtpi. ok let me ask this now...what TPI cam kit is a good choice for a ZZ4 w/stock ecm if I go that route? a link or part # would be great!!!

Abubaca

iTrader: (3)

If you're gonna spray it, you'll want forged pistons. The ZZ4 has good hypereutectic pistons, and "should" be ok, but as you say...."do it right" so I'd opt for forged. ....pretty sure a good cast crank can rev into the low 6000s without issue, and is good around 500 hp, so "they" say. ...and nodular, even more ...but having the forged crank in the zz4 is sure nice. In my opinion, it's overkill, but...if you can afford it, why not???

As for cams, I'm actually running a zz4 cam and although I have a custom tune, it ran great on my stock tune/89 MAF car. SD cars probably will HAVE to have a tune. ....I also like a LT4 Hotcam sized cam on the larger side of TPI friendly cams, but you will HAVE to tune the car, no doubt. Does the Scoggin Dickey TPI motor have the Hotcam??? I thnk it does. Look at the specs of what the crate motor companies are putting into their engines. See what kind of idle quality they say they have, what power and torque, what intake set-up they run and whether or not their able to pass emiissions etc. etc. Look at what size heads they're running. ....that'll give you a decent idea what cams work in what engines. Sure, you can get more power with a custom cam and tune, but they're all gonna be pretty solid combos.

3rd-gen's 4life

Thanks for your reply the only real reason other than the crank in the zz4 is I'd have to buy heads and would totally go for a set of l98 AFR's but the scoggin dickey tpi don't list and specs at all!!! seems to be the only one guess I need to talk to them to get that all summed up. and there is no tuner around me in these parts really other than mail order and don't want to have it sitting any longer than it already would be that's why I'm trying to go with a 350 ci block to maybe get lucky using a stock ecm or trust me I'd be on another page saying 383 potential lol.

Abubaca

iTrader: (3)

What intake do you plan on using? Bone stock TPI? Modded TPI? HSR or MR?
The Scoggin Dickey motor uses (I think) stock L31 vortec heads with a valvetrain to accommodate the higher lift cam. Good heads, but not AFR good. They're a 170 intake runner which does promote low end grunt, and they're essential fastburn chambers, so it's a great option, BUT....they're still not AFR good. I think this is a GREAT option right out of the crate, but if you do your homework, you can easily piece something together that'll make more power. Again, not knocking it at all. Depends how much work you wanna do on your own. Keep in mind the Vortec head rage was caused because they're cheap, and perform great out of the box. For most of us late model EFI guys, we add cost to upgrade the valvetrain for bigger cams, and the poor flowing TPI/vortec pattern manifold cuts off a little performance. At this point you lose at least "some" of BOTH benefits. Savings and performance.

If you go ZZ4 and add a set of...say....AFR 180(185?) heads and maybe put on a modded and ported hi flow TPI, or even an HSR, it'd be a lot more fun!

Abubaca

iTrader: (3)

Also, don't plan on NOT tuning. Private message Tuned Performance. He's got a pretty good reputation on the boards.

3rd-gen's 4life

I was really hoping on not having to tune if scoggin dickey tpi was just gonna find a tpi 350 vett ecm or maybe locate a accel even or I can get any tpi ecm from my work "junk yard". but I have researched that edelbrock are the largest runners out of slp and accel by dial caliper tests and plan on getting both edelbrock runners and base and having High Flow Fuel Injection - Porting - TPI / L98 / TBI / LT1 / LS1/ L67 / L32 stage 4 port work done. his work is great! ok here it is zz4 with afr heads then call comp cams what ever big cam I "can" put in edelbrock base and runners stage 4 port work mono blade TB new injectors flow matched rebuilt oems and I guess mail order tune if not the option you listed above. and yes I know what your gonna say but full emissions headmans shorties egr etc with dual cats....I call it super stock sleeper!!! well I was trying to add a picture but "paste" button isn't highlighted idk.

3rd-gen's 4life

let me ask this...l31 long block is like $2,000 roughly so for a cam and base its quite a bit more so paying for the work I guess and from what I gather is a lt4 hot cam right? I did find a web page that said there dyno run on the 360vtpi was 284hp and 330tq at the wheels from 360hp at the flywheel so that's like a vette tpi pretty much lol thanks for all your help thou Abubaca

3rd-gen's 4life

AFR# 0919 180cc/65cc L98 heads $1564 looks to be fully assembled. and ZZ4 short block $2,489.85 = $4,053.85 add cam and lifters for roughly $800 still not as complete as the scoggin dickey but for the additional parts needed I will feel like I made the right choice with the 360vtpi being $4,750.95. 8)) another year before she will be done but this 350 powered 91 z28 will be sweet I think!!!

Abubaca

iTrader: (3)

Well see now you're bringing a few different things into play here. That L31 Longblock is a whole nother discussion!!! ...Easily the cheapest overall, and best bang for your buck would be pick up that L31 longblock, get the biggest cam that comes in under the "about" .470" lift limit on those stock vortec heads, get a vortec TPI base, and drop it in. You could probably be up and running for barely over $3000 and you'd perform WELL over any stock L98 350 TPI. ...AND.....if you're running MAF and not SD, a stock L98 tune will work well.

....now the Scoggin Dickey engine bumps the valvetrain up to handle that much bigger cam, and adds a higher flowing TPI, although you're still somewhat limited by the Vortec TPI base. Still a stout engine, still good bang for your buck. More money though, and you're basically running a stock L31 shortblock. Great for a street TPI, but you said nitrous, right???

...and then of course the AFR head/ZZ4 set up. That's basically your best performer, and also the most expensive. Isn't that how it always works? ...and both the ZZ4 and SCoggin dickey are going to require tunes. I still think the zz4 shortblock and AFR head set up is overkill for what you're doing. For that kind of money and performance, I'd go with a Stealthram or Miniram, not TPI. ....but me personally, I'd keep the TPI, but spend less. Find a smaller cheaper, but efficient head, and put it on a solid reliable, but maybe not the BEST performing shortblock. That L31 is hard to beat! ...I dunno, it's trick....SOOOO many factors

Abubaca

iTrader: (3)

OR.....(see..this is how it always works)......pick up that L31 longblock for $2000, spend a little and get the heads(valvetrain) worked to accommodate a larger cam, get a bigger cam, and then run a vortec stealthram. No limitations of a TPI vortec base, spend BARELY more for the entire stealthram, thanyou would for just the vortec TPI base, and no flow limitation! That L31 comes with the strongest factory block chevy ever made, and a rock solid nodular crank. You do have non forged dished pistons, but it'll still perform awesome. Just don't spray it. (much) Basically it's cheaper than the scoggin dickey TPI, but it'll outperform it.

3rd-gen's 4life

Abubaca Thanks for the reply...I have some time to research all my options and will. First off the complete stealth ram is about $3,000 and vortech base is about $400 guessing you got lost in your wording on that no biggy but love the old style TPI idk why but...really trying to go the distance with it and I do have speed density to add that! but thanks again gonna go search and find all I can about this "L31" ttyl....

Abubaca

iTrader: (3)

The Stealthram you're looking at for $3000 is the WHOLE fuel injection system. Computer, harness, injectors EVERYTHING! ....just the manifold itself, 1 pc. upper and 1pc. lower is about $400. Then another $200 for the fuel rail kit, so about $600 total. Everything else from the TPI set ups works. I think you may need a fuel line fitting here and there, but it's very minimal. I'm 100% on board with keeping the TPI, but dollar for dollar, short of just bolting up a carb, the stealthram is the best bang for the buck by FAR!

....as for the L31....it's not perfect, but for the average street 350, it's darn close. Lots of guys using them as the foundation for 350 street motors well into the mid 400 hp range. The nodular crank is far stronger than our L98 cranks, the metallurgy in the block is stronger, and the tolerances are darn close to LS tolerances. Then of course it's assembled by GM. Reliable, reliable, reliable. It's the last traditional small block, and they had plenty of time to get it right, and they did. Thousand and thousands of heavy duty trucks and vans running them into the 100s of thousands of miles.The only thing I don't like is the dished piston, but that's a minimal issue for what you get.

Jazzyjeff87

I had tpi Cars that wear freaked.... No lie to god. I had a bone stock tpi 350 91 formula ,true dual exhaust, cats, bullet mufflers. Slp intake, air foil, pulleys.... ..it ripped 14.06 at 104 mph with 2.0 60 ft. 54,000 miles. I had a 87 iroc burned oil. Check engine, ripped every single sensor off it and smog pump. Custom intake out of Monroe exhaust pipe. 134,000 miles... Vince's garage helped. In Albany NY ... He's the man Dan fillipello... Nitrous express 150 shot wet system. At 2 gear 275 drag radials.... Spayed the shot out of it...... 72 passes.... Best pass. .. 12.24...109 meh 1.70 6ft.smoked a 96 viper. I had tpi freak cars. Everyone seen them I don't bullshit.