formularpm

Thats false. If two heads are identical in every aspect except the metal they are made of, they are going to flow identically. The iron head will insulate better and make slightly more power because of it, but the aluminum head will tolerate more compression due to better ability to disipate heat. Both heads have advantages, the aluminum is just more expensive but lighter and easier to modify/repair.

RobsWS6

LT1 has been around since 92 and has been modded since. True the small block has been around since 55 but the LT1 probably has just as much, if not more, stuff you can do to it.

There are some N/A LT1's in the 9's(388+ CID). Don't know how many tuned ports are there but they came out in 85 so they have a few years on the LT1.

If it were me, I'd swap an LS1 and go from there. But that is expensive!

After that, I'd stick with the old fashioned small block. Many head choices. Use the LT1 intake as a cheaper alternative than modding the TPI. It might cost a little more in the long run but I think you'd be better off.

90rocz

The LT1's main (so called)advantages are the shorter runner intake and taller port heads, why is spending $1200-$1500 for a motor and extra $500 or so in adapting it and maybe $1000 in labor for someone to install it, a cheaper alternative to buying a HSR or MR + F/R + WP Heads + cam = $1600????

And as for stock iron heads, mine are rated at 285/300HP STOCK!
(Part#10125377 or casting#14011083)
I'm looking at getting a little over 400HP out of them and putting only $250 in them, very much worth my time, to me...

Because I can, and am willing to port my heads, I won't spend $1,000 for a set of aftermarket heads that will flow the same as mine when ported. I guess I've always been one to want to swim upstream, but I've learned a lot that way...

Airflow = HP and heads are where it's at, I know...but I'm not willing to shell out a grand for minimal gains over what I'll have.
When I buy aftermarket heads, they'll be Aluminum, so I can run another point of compression on pump gas, and they'll be supporting more than the 420HP combo I'm building now...

You don't see many fast TPI's out there either b/c most want it "fast & easy", they give up on the "Tuned Port" b/c everyone tells them they can't do it with LTR...Guess I'm hard headed there too.. When I get told "you can't do it", I become more determined to prove them all wrong..

And for "the guys in this forum who dump a ton of money and run 13.50's....Combination is EVERYTHING!...That goes way beyond just heads....Buying aftermarket heads will NOT improve this.
If they install a set of 230+CFM race heads, a 240*/ .540" cam, MR and don't address programming, injector sizing, gearing and stall etc....or if the cam doesn't operate in the heads optimal flow range...They won't go faster than 13.50's either! And they will have spent a TON MORE money...
BTW, I know I'll hit high 12's with my combo(ported stock heads), I'm gonna try to stretch it to the mid-low 12's tho.. ...we'll see this spring!

Camarocracy

Go with an LS1

dj haf

ls1's are bad ***... but they're really expensive to mod. would rather build my own sbc and make it out perform a modded ls1 for way less than what it would cost to buy an ls1 and put the same mods on it

BOZS89IROC

TPI's are known to be better for low speed and mid range power because of the longer air runners. With a modest amount of mod's it could easily keep up with an LT1. It is all a matter of personal preference. LT1's are more technologically advanced and there is a large market for them. TPI's have a huge market and so far have a wider range of user's because of the ease of install into cars of all sorts. Remember that the 1st Gen blocks have been used since 1955 to 1994.

BOZ

jonesy91z28

guys I am in no way tring to start a war with this comment but does anyone out there have a stock headed, no nitrous, no superchargered l98 that can run 10's or 11's? And if so how many are there? two or three? With this in mind how can anyone say a modded l98 with stock ported heads,cam, and programming will run with a stock ported heads, cam and programmed lt1? Just looking at the facts. Not trying to start another war here. If anyone has facts to back up the l98 just lets us know. Maybe this coming year we all could get together and have a lt1 vs l98 heads up shootout. And just let the track times speak for themselves. Anyway as long as we are all busting those mustangs that's all that really matters.

Teek

I know "The guy" who got 248cfm@ .480" lift out of his stock 083 castings, with larger valves. He was assisted by the owner of Cylinder Head Specialties www.cylinderheadspecialties.com and his heads flow great on the exhaust too (185cfm@.600" EGR port)

He also siamese ported his intake manifold and it pulls HARD up to 6500rpm with STOCK runners now. No track times yet but I'll let you know when he gets his @ss to the track.

steve10358

I don't see how it can pull hard with stock runners. They are like straws! TPI always fools the butt-o-meter, though. Let us know if you get any numbers next year.

TPI SUCKS!!! You can't lump the potential of the 50 year old SBC into the tiny 7 year window that TPI was around. You can't do anything with the TPI that GM had. You'd have to convert a carb intake over to get past that and still have FI.

The LT1 intake can help, but you can't get much more than 270-high280's out of it... which doesn't support all that much power for the guys that have more money than me.

The real problem is that no one has ever organized a race series that focused on just the F-body. But there are tons of series with SBC's- so that's where the technology curve goes. Look at the Mustangs if you don't believe me. They've got several race series, and you can cheaply get a Stang into the 9's, and it's not just cause of weight! It's really too bad the F-body never saw that... but then again- all of us bickering, undecisive fools helped bring it down too. LOL.

"I like new ones"
"No, I like old ones, new ones suck"
"Well, I don't like the rules"
"They were designed around politics"
bicker bicker, fight fight.


LOL

Merry Christmas!

S.

90rocz

TPI's suck, LT1's suck...lets all buy Mustangs..

steve10358

You're missing the point.

1. TPI does suck. Pure Garbage. Anyone who says otherwise has never hung out near a flow bench before. I do wish I didn't have reverse flow though... it'd be nice to just throw a set of heads on my T/a.

2. LT1's had some improvements, but still have $ome flaw$ overall- and a very limited aftermarket. Also- what would be the incentive for a hardcore racer to chose our vehicle, aside from personal preference? They're heavy, the intake is trash if you wanna compete in a serious race series, and you need to convert an aftermarket set of heads over to get anywhere, if you don't wanna dump $4000 on the right AFR's.

3. I WISH we had the industry support that the Mustangs get. I'm a realist. It'd be naive to think F-bodies are all there are. Let's all face it- as much as I love the F-body, it's DEAD and we are left in it's wake.

There's no way around it.

Keep in mind- I'm not trying to insult anybody, and there are certainly many ways to skin a cat- but there are a lot of misconceptions here. I am trying to argue the fact that a third gen really does have more options, the LT1 and LS1 aren't the end all's to the SBC, and if you wanna get anywhere, scrap the only real weakness... the TPI.

Later.

90rocz

Do you have flow bench numbers for a TPI??
I do get near a flow bench once and a while...I HAVE seen "ported" stock TPI intakes only give up 12HP to a "SuperRam", is that garbage...if so what is your yardstick to gage it by???(That was w/o adding aftermarket runners or base.)
The SuperRam has a much shorter runner too...

I'm just saying, I think there are a lot of misconceptions too, in the other direction.
I'll agree with you about more options out there for the L98, ofcourse. And NO "All Out Racer" would even choose an LS1, but that's NOT what we're talking about here.
We're talking about a fast daily driver with very streetable manners...I still believe a TPI can accomplish this...
I've already shown you one(TPI) in the 12's, do I have to find one in the 11's, then 10's.???
How fast will make it NOT garbage???

I guess I'll be the only 3rd Gen staying true to it's design, powerplant & all...at least for now...

(I guess next we'll see LT1's in F150's???)

steve10358

I don't know, maybe it's cause all my friends are in the 8's and 9's, that I think 12's is ho-hum now-a-days. No insult to anybody, I run 12's and am dissapointed.

Sure, TPI cars can run 12's. All it takes is a few bolt-ons, and the right combo. But once you start getting serious, it becomes a major drawback. Show me one NA Stock intake TPI car running -9's, much less 10's or 11's that hasn't been gutted- and I'd be impressed...but you're never gonna find one.

Heck- I've seen a couple LPE 383 C4 Vettes w/ Ported heads and ported stock TPI's that couldn't bust 108-110 in the quarter. Tell me that's not a waste of money... all cause of the bottle neck up top. An NA 383, should at least run low low 12's @ 117.

And even in the long run- it's more about combo than anything. Just cause a near stock TPI motor runs high 12's doesn't truly mean that's a reflection on the intake. Nothing was really done to make the engine draw in that much more air to tax the intake. Start adding real heads, and a cam- and it's all restriction from there.

That's why so many guys run 12's with such a low MPH out of these cars. They make mods to take advantage of the torque, but the cars all nose over in the end. It's just the nature of the beast.

You're cutting yourself short. Out of the thousands of TPI cars out there, there is no point in keeping to the original anything. These cars will never appreciate. There are two many of them. Not only that- but isn't the goal of all of this to go fast? Why cut power output down for the sake of a TPI fetish? There's no point!

But hey, to each their own. This conversations getting too hostile, and I'm done. A car's just a car.

slimdawson

So a stock 350 tpi with ported heads and an intake can kill a slightly modded Lt1?

I am not saying my car is fast but I would race somebody quick that said all they had was ported heads and an intake on a stock 350 tpi. I imagine there is somebody out there that is running 12s but how is it going to look after the 1/4.

Now put in a nice cam and a really nice exhaust with all the bolt ons and maybe.

Black6SpdTA

Great post Steve.

I agree that TPI becomes the bottleneck once you change heads/cam/displacement/etc. If you're an all out drag racer, then yes, TPI sucks. But for a street car, TPI rocks. Nice low end torque on the street. It's great! Even if you're a road racer (me in 5 years ) the low end torque is great for boosting you out of turns quicker than a similarly equipped LT1/LS1 car.

One problem I saw with your post: The 9 second stock intake car comparison. Why pick the intake when we're comparing engines? I've never seen an LT1 with a wet OPTI run 12's, let alone run. TPI cars can run 12's with wet engine compartments

-Rippin