Is 383 cubes to much for the Tuned Port Injection system to handle??? At what RMP does the TPI, run out of breath? The setup is: LTR, 52mm Throttle Body, Ported Pendulum. Big Mouth Base. Thanks.

Many say so. My last dyno pull makes me believe it.
My curves peaked at 4900 rpm.

Its not as bad as some claim but you should expect to make peak power somewhere near 5K.

its all how you build it. On my car it makes power until around 6400 rpm. It peaks at 5700 and stays fairly level until 6400

Ah! I searched for quite some time trying to find that link, it's going in the bookmarks this time.

TPI can be made to flow quite well. Don just had an Accel TPI intake manifold ported and it flowed 326cfm and 331 cfm between the ports. Stick on a set of opened up and siamesed SLP runners or a opened up Super Ram and you have a system that can support up to 600 hp.

By the way some of us feel the Accel TPI intake manifold is the best one to start with outside of the First. Unfortunetly it is no longer made and has to be bought on the previously owned market.

I run in my new 383 with my old TPI setup ; siamised base , SLP's and ported plenum .It spun over 6K but I know from the intake comparison above the power would have been flat over 5K. Impressive bottom end, traction problems on ET streets
Swapping to a HSR on the same tune dropped me straight away from 12.7 (A4 3.07) down to 12.3 and helped off the line because it dialed out some of the bottom end torque ; not that you would notice

i have a 450cu.TPI i ran accel d.f.i , 83lb injects, with a comp cams, heddman heads justable regfully ported plenum an runners, with a 64mm body airfoil sounds dumb but also the tps throttle enhancer,also with the msd 7al hooked to thepro power coil mine peaks at bout 7000 rpm

What cam and heads?

AFR L98,195cc comps. beehive springs, with the mag. comp rockers. its a comp cam i for get the lobe, lift an dar. off the top off my head lol

Dude is yanking your chain.

What kind of 1/4 times are you looking at? This is the same setup as I have, minus the Nitrous Port on the runners. Nice to see someone has gone down that same road.

Just testing , 7K on a big cube TPI

Haven't been able to make it to the track.
Have you?

think im yanking chain but i gott dyno papers to prove it wanta see them lol

I had the bone-stock TPI on top of a mild 383 in my 1990 Vette. It only made 250rwhp, but held 300+rwtq from 1800-5200rpm. The party was over by 5400rpm, though...

It was a really fun street engine coupled with the 700R4 and would just liquifey the tires at any provocation. It may not have been the fastest car, but it was giggle-inducing stupid fun...

No I haven't made it to the track, you must not follow my posts. Hey where's the dyno numbers/graphs for that 454 TPI, let me see that.

I have a stealth bomber in my backyard, too, but is invisible in the photos I take of it, because it's Stealth!!


TA

Maybe it used to be TPI and has a Miniram or a singleplane intake now,,, but it's not doing with a TPI - long runner intake. It's physically impossible as in the PHYSICS involved make the long runners incapable of making peak power at 7000 with a 450cid engine. Period.

Somebody just got destroyed by the scientist.

.... yeah, yeah, that's the ticket!

http://www.youtube.com/watch?v=YLyyPCbxnIU

lol i never said that my intake had the runner an stock plenym on it ,im using the miniram system

So it is NOT a TPI anymore is IT?
Once the TPI comes off it is just another SBC

OP asked about TPI limitations on a 383 ; not MR

Yes... What are the limitations of the 383 cubic displacement SBC, with a TPI system

You need to go by Dyno Don's shop in Orange and he can tell you all about TPI. Depending it can support say 600 hp.

Maybe Maybe, Dyno Don, from orange can chime in. Thanks.

yeah but what you guys are doing is taking TPI and making it an effective single plane type intake... its no longer "TPI" by definition, even tho its using TPI base and TPI runners.

But if you want TPI looks and bigger inch motors and wish to go fast, then doing what Dyno Don and JerryWho and others have done is the only way.

I think JerryWho and Don are taking TPI/SuperRam to another level. This is just a little teaser. On the outside it will look like a factory piece to most.

Is there a way to see what these two guys Dyno Don and JerryWho are up too, without going over there?

It is their project and I probably should not have said anything as very few know about it. I will say it appears like the setup will flow some serious cfm.

Lets hope they let out their secrets...not sure why they would want to keep it hidden from the rest of the community that can seriously benefit from their knowledge and findings

Hi Orr

I think they will in do time. One thing we have found out over time is the Accel version of the TPI intake manifold is the best one for most. It has the most bang for the buck with any additional work. I put the First in another category.

Where are the secrets?? It's been months!

Basically open up the after market intake manifold (original Accel best outside of First) to flow around 330 cfm. Siamese, add some weld to SLP runners and open them up to around 1.78" diameter. Leave 1 to 2" of runner left where it bolts onto the intake manifold. Open up the factory plenum to match the runners and maybe fit a 58mm throttle body.

My TPI combination makes peak power at 6400rpm. Just ran a 12.09@113+ over at California Raceway in Fontana in terrible air with a density altitude of 3100ft plus. This is an A4, 355 cubic inch motor and a heavy fully loaded GTA.

ahh man I thought you said it looked stock. siamesed runners≠look stock.

and just to reiterate. mini-ram is not tpi