Thirdgen89GTA

iTrader: (5)

even though that’s a aftermarket package I don’t really consider it aftermarket because it’s using a GM pcm.

drb930

That’s the Beauty of it

newbvetteguy

Any that support the features mentioned.

Sequential injection, CNP, open valve injection.
Which is most of them, at least with some upgrades.

I have Holley HP with a CNP harness added on; FAST can do the same, I think even the more turn key Edelbrock EFI can, too.

The biggest benefit is not having to burn chips and email a tuner. Hook it up to a PC and if you want to pay a tuner they can remote in and tune it remotely.



Adam

newbvetteguy

Not very much, IMO.

Stock TPIs overwhelming limitation has been proven a hundred times to be AIRFLOW, and not runner length. No reason to do anything before addressing airflow.

After that, the limitation with stock length runners becomes that you’re not going to make more power by pushing the RPM up, so you have to get closer and closer to max cylinder pressure and combustion temperature for as much time as you can and detonation becomes the limitation. -This is where cold air, cool coolant temps, cool oil, great quench velocity, AND things like open valve injection and big injectors come in handy.

A high compression, FIRST build with E85 or Methanol would be awesome to see as you’d have huge octane benefits and air temp cooling benefits to chase those gains. (E85 is nearly non-existent where I live, so I’m not going to do it, hence my interest in OVI.)

Good long runner builds just become RPM limited which makes increasing the cylinder pressure the way to chase gains and then detonation/ octane limits are the enemy. To chase the power on pump gas, OVI is helpful.


Adam

Thirdgen89GTA

iTrader: (5)

or……


modern efi system + BOOOST.


I wish they made a LS style integrated supercharger for sbc so it would have a lower hood profile.

newbvetteguy

Boost is one way to make more cylinder pressure.

The Vortec kits for TPI engines doesn’t increase the required hood clearance, does it?


Adam

Thirdgen89GTA

iTrader: (5)

I like the screw/whipple type more than Centri's. I prefer Turbo over both though.

newbvetteguy

For anyone considering converting a TPI to a more modern EFI system, FiTech sells a few EFI systems specifically for TPI conversations:

This is the highest end one and it supports dual, wide-band O2 sensors and does lockup control from 200r4/700r4 transmissions. For $995 https://fitechefi.com/product/38351u...al-o2-sensors/

They have a TPI system for as cheap as $795: https://fitechefi.com/product/38350t...ne-efi-system/


There's a Holley Terminator X "Universal MPFI" kit that provides a LOT of the goodies to make this work for $1,249, but you'd need to talk to Chris @ EFI System Pro on EVERYTHING that would be needed for a Terminator X to control a TPI engine. https://www.holley.com/products/fuel.../parts/550-936

I went with the Holley HP which is a step up, but also a couple years older than the Terminator X and it's pretty ridiculously priced at $2,360 now! From memory it cost $1,600 for me to get most everything I needed when I bought it and I thought that price was pretty crazy high at the time. https://www.holley.com/products/fuel.../parts/550-601 -If you want CNP you'll need to buy the "DIY CNP extension harness", and if you want a fancy crank trigger setup, then you need that, too...

The Terminator X can support sequential multiport and CNP out-of-box, so despite being less powerful it really is a way better deal, IMO than the HP unless you're doing lots of very serious race things.



Adam

BuzzLOL

Richard Holdener has now converted his old 2004 classic definitive Super Rod 10 TPI, etc. intakes on a SBC 383" dyno comparison article into a video:

newbvetteguy

Plymouth?

newbvetteguy

(The name of the rock you've been living under?) -That video came out 2 years ago.

I'm feeling "froggy" because it's Friday!
;-)

Adam

BuzzLOL

Actually, I thought thirdgen was long defunct... but I see it's still up... and the previous copies of this article have been removed... and the earlier links all obsolete... so there are probably 250 or more posters in this thread plus new people who would still like to know where the article can be found... and there are people who think air flow is TPI's limitation... not the ram effect tuning that whacks off HP above 4500 RPMs... or that think the stock cam is too small... actually, the stock cam wants to HP peak around 330 HP at 5200-5700 RPMs with a carb./carb. intake... but the stock TPI flattens the HP curve on the graph at 4500 RPMs with a 350" or larger engine...

Fixed previous posting... SBC 383... of course there are millions of homebrewed and aftermarket ones... Chevy also sells Vortec HT383" over the parts counter...
https://www.motortrend.com/how-to/gm...-block-tune-up

Tibo

iTrader: (15)

With todays options can't imagine spending that much money on a SBC intake. $1834 + tax sounds ridiculous. Even the 70+ year old car guys at the car shows who grew up on carbs are switching to newer engine swaps. TPI is fun to reminisce about and I hope nobody is using this information for anything more than nostalgic purposes.

BuzzLOL

I'm 70+, grew up on carb.s, boost, and EFI, went to a car show and veterans B-B-Q today, and not going LSx...
.
https://i.pinimg.com/originals/0a/6e...f04eb7a4b5.jpg

drb930

I’m 66, & my 400+ El Camino with a SuperRam is going to get a little bigger cam and an LS 0411 PCM.
It runs just great and this just reinforces that I made the correct manifold decision.
I wanted a car to be a Classic, Hotrod, Tow Vehicle, & a Truck all in one!

newbvetteguy

Airflow and intake runner area ARE a major power limitation to a TPI; cam duration can also move the curve a few hundred rpm in either direction.
The stock TPI's 1.5" inside runner diameter (1.76" area), along with the curved runners WILL start to run into the "port limiting velocity" of a 383, even if you're able to provide it the air flow to keep making power to there or past there.

ThirdGen member BadSS made an epic series of posts on the subjects including EA Pro engine simulations that duplicated the results of the "10 times the power" article and engine combos, and then showed what can happen just by providing more flow and more intake runner diameter / area to a TPI combo in this thread on the Corvette Forum: https://www.corvetteforum.com/forums...post1604823933 -The 2nd graph which shows the FIRST Fuel Injection TPI intake with a stock 1.75" inside diameter (2.4" runner area) moving the hp peak to 5,000 RPM. (And he didn't account for the slightly shorter runners that a FIRST has in that simulation, if I understand correctly.) -He then ran the sim again with a cam better matched for the FIRST and the HP peak shifted to 5,200 RPM.

The runner length definitely determines the shape of the curve, and drives the reflected wave behavior of the intake, but air flow, cross-sectional area, and the cam duration can all move the exact rpms "to the right"; the runner length is not some "magical wall" beyond which no additional power can be made. Some of the really good long-runner builds have shown signs of starting to pickup the 2nd reflected wave, too.

My FIRST SBC 350 long runner engine peaks at 5,850 RPM; and TPI engines will often have more AVERAGE power.

The best average power to 5,500 or even 6,000 RPM can be had with a GOOD TPI combo, and if that's the RPM range you want to run in anyway, IMO, it's a great option.
RCS Racing Engines sells a FIRST TPI-based SBC 383 crate engine with an AS-cast FIRST TPI intake and as-cast Brodix heads, and a reasonably smallish roller cam -with a warrantee that makes 460 hp @ 5,200 RPM, and 520 ft lbs @ 4,000 RPM.
-Better heads and a better cam can move that hp peak up another 600 rpm, and the hp along with it ---all with a 19" intake runner length. RCS Crate 383 HP460.T520 SB Chevy EFI (rcsracingengines.com)

For max hp under 6,000 RPM a TPI style long-runner intake that actually has appropriate amounts of cross sectional area and good flow makes average hp that's tough to beat, if you feed it good fuel and a good tune. (Cost IS a legitimate concern, though...)

TL;DR version: Runner length makes a limitation on where peak power can occur; it can be moved considerably higher than post people think with enough intake port area and flow.If you want peak HP at >6,000 RPM, then a long-runner intake should be off your list. If you want max average power up to 5,000 -6,000 RPM, good airflow, the right cross-sectional area, and an aggressively lobed cam is the recipe.

Adam

newbvetteguy

It sounds cool as hell! And I'm sure looks it with that pizza box intake!

Adam

Thirdgen89GTA

iTrader: (5)

those rcs synod numbers have more in common with old Gross ratings than modern engines. If that was measured in a car to the wheels be prepared to see more like 350whp to maybe 375whp.

compared to a modern gen 5 making 455hp which is sae net at the flywheel.

sure thr torque is nice but there is a reason mfgs have moved away from LTR setups and settled more on mid length setups.

BuzzLOL

The trick is to make grossHP rating close to netHP ratings by limiting accessories such as belts, A/C, PS, PB, restrictive air cleaners, restrictive stock iron exhaust manifolds, restrictive exhaust setups/mufflers, small/single exhaust pipes, A.I.R. pumps, EGR, etc...
https://www.dailymotion.com/video/x3rfhrk
Yeah, Chevy went too long intake runners with TPI EFI... then too short runners with LT1 EFI, then mid length runners with LSx EFI...
Of course, GM started EFI V8s with '75 Cadillac Seville using EFI Direct Port Injected 350" Olds engines with low rise single plane aluminum intake manifold... too bad it was still somewhat of a 1970s emissions slug engine...