Brett Richmond

I am in the process of getting ready to build my motor finally,I have been looking into a 383 for my 89 vette.I have been reading up on different combos and I have come across different articles in Corvette Fever Feb. 99 and Vette Oct. 98. where the owners have respective got 430 and 460 HP out of the motors with a ported TPI and base w/siamese runners. Now motors where both 350s with compression of 10:1 and 11:1, both had cam specs of .487 inch of lift on intake and .524 on exaust, the other one had .525 on both sides. Heads on one was 2.00/1.60 for the intake and exaust... Does this sound right for what they had or did they stroke the motors to get this power or were they BSing in the articles to make it sound better?????

Sorry for the long post but I need to know about which route to take with my motor???????

Beach Bum

Sounds like those articles are a stretch... it would be very tough to do with a 383, let alone a 350 cubic inch.

I doubt if anybody has achieved 400 flywheel ponies with a ported stock TPI set-up... just too hard to get it flow enough to support that HP goal.... but I think somebody could come close with a 383. As a note, Lingenfelter has a 11-1 cr 383 motor with large Accel Tube runners, ported plenum, 58 mm TB, Accel base intake manifold, heavily ported D-ports, LPE 74211 cam and headers that they advertise at 395 HP @ 4600 rpm and 450 ftlbs of torque at 3400 rpm. I would guess the stock TPI even ported would set this back anywhere a mininum of 10-15 hp and probably 25-30 hp.... but you never know.

My only comment to somebody who is committed to forego the Superram or Miniram and definitely staying with the long tube runners, to look at the ASM runners.... for reasons I don't know, they seem to always get a few extra ponies over the other brands.

good luck
Beach Bum

ANTI VENOM

TPIS claims that they made 408 hp with a 350 I believe......It was with a zzx cam. :bs

Cory@LS2PortWorks

TPIS claims a lot of things

Cory@LS2PortWorks

... and most of us bought off on a large amount of it. At least for a while


[Modified by CHarris85Vette, 10:34 PM 9/30/2001]

ralph

btw, i once spoke to Myron Cottrell about that xxz in the 350 (as THEIR literature states). The very arrogent Cottrell practically balled me out for suggesting that cam in a 350!! I had to remind the ********, that it was HIS combo that was questioning.

smallblock

My friend has dynoed 324 rwhp(around 400 crank) with a 350, accel base,AS&M runners,52mm TB. As Beach said, the AS&M runners flow the best,and you will need an aftermarket base.

89'Bowtie

I got 350 engine hp out of my 89'. Nothing Wild...


ZZ4 Cam
Port Matched Heads-just a flash clean up
Ported Pleneum
Mildy ported/touched stock up base
52mm T-body
Hooker headers
10.5:1 CR

Car put 350tq at the wheels before the Headers and 330hp at the motor.
At the very end motor had around 350HP. I wanted to add the aftermarket
base and ASM runners, but accidents happen and one happened to the car.
It's no longer with me, but had a lot potential, no matter what people say of the TPI.

With a 383, 400HP should be no sweat, LPE does it all the time with his combos. But if i did 350 with factory heads and and 208/221 cam. Heck,
the 383 will make tonnes of hp and tq.

Good Luck,

P.s I was going to put on some Canfield hads. 195cc intakes that flowed 258cfm. THere heads a great and only cost $800.OO A pair. But never got
around to it.

1991Z07

I've got very close to 400 and maintained the drivability. It can be done, but not with the stock base-plate or runners.

Good luck on the project..

WHRITZY

Anyone know where to find info on AS & M runners?

BBA

Ahhh...the great TPI 400 HP debate rages on....

:jester

Ok, all seriousness...I plan on doing just that.
I am of the firm belief that the TPI airflow is not the real power killer here...especially not if you siamese the lower intake runners and port the upper plenum. I do believe the cam is the limiting factor...I mean geez luize...LPE is selling the "219" cam as it's best power cam??? HELLO...McFly...HELLO!!! That is a W-H-I-M-P cam to the max...heck, I'm surprised they even turn 5500RPM with that under durationed POS in the first place.

Then you have the injectors...without 30-35PSI injectors...it ain't gonna happen!

So, in all reality....I guess the stock TPI will NOT make 400 HP...but it doesn't mean you can't MAKE it do it

Beach Bum

BBA,

Just a few questions regarding your post. You mention that you have found the camshaft is the limiting factor on a motor with the stock TPI components sitting on top of that. What camshaft did you find that allowed the stock ported TPI to move its HP peak up above 5000 rpm ?

You indicate to the original Poster than he can make over 400 HP with a 350 and the ported stock TPI, don't leave us in suspense like that, if you could please share your 400 hp 350 ported TPI components recipe !!! I know a lot of forum members would love to hear about the Recipe that does this.... not to mention a few aftermarket tuners. And of course any proven examples of the Recipe that you have would be appreciated too. Please include the cam specifications or cam card, chosen heads and degree of port work, runner size, chamber size, etc...

I notice that your advise is to make sure you have at least 30-35 lb injectors if you expect to make 400 hp or more.

How did forum member Ralph run in the 11's with 116 traps with 24lb injectors ?
How did forummember JD383 run in the 11's & 117 with 26 lb injectors ?
How did forummember Bowtye8 run in the 11's at traps around 120 mph with 24 lb injectors ?
How did I run 11.61 last weekend with a 2000 ft DA with 24 lb injectors ?

Thanks for the help.

Always willing to learn.

Beach Bum

BobMachus

arizona speed and marine

I think SpeedDemonMotorsports sells 'em.


[Modified by BobMachus, 9:02 PM 10/1/2001]

BBA

...Well, maybe a high flowing set of 24 pounders and higher fuel press?
Not saying anyone with 24 Lb injectors won't run good...but my recipe you've already seen... ( If you don't remember...I will search and dig up that controversial link that you took no small part in conversing with me on this particular topic :D )

Besides that, running the 1/4 mile in Z seconds does not mean you have X horsepower...it just means you have an average of X horsepower for a long enough percentage of time to move your car as fast as it did... IE: 350 HP for a whole complete run ( I know it's kind of weird to think about it as a flat HP-RPM curve for the whole 1/4 ) will outrun a 600 HP car that can only make 600 HP less than 10% of the run because it only hits the powerband at the top of each gear and the wrong converter. So, I tell you, it does NOT take 400 peak HP to run 11 Sec 1/4's just one heck of a broad powerband and a converter that keeps power at the power making RPM the whole way. ( and we all know that you spent $700 on "THE" converter to make sure this happened :D )

I know your gonna throw some Trap speed is HP line out here sooner or later...so to that I say, it only takes about 60-80 HP to propel a car at 120MPH or so So trap speed is not a true indicator of HP, it only correlates to it by circumstance

Now, Have I proven my 400HP in TPI trim yet? No.
It's only a problem of time and money right now...at this stage I have little of both to throw around, but I have most of the components to make it...after the 79 is gone ( soon I hope ) I will be starting on it...provided my job is still intact ( company is being sold at the end of Nov' and we might be all laid off then... ).

So, to answer your querry...I guess I can not 'PROVE' it yet...but have a little faith...you'll see it :flag




[Modified by BBA, 11:10 PM 10/1/2001]

EricVonHa

More flow, more go. It's very easy to get over the 400 mark as soon as you start raising the cubes past 350. My LT-1 goes 360hp at the wheels with the stock (highly ported & matched) manifold with the stock casting heads with a full port job and larger valves, no cats, ZZ9x cam and all the other ancillary bolt on goodies... Low 12's with drag radials and a slipping 6speed clutch!

TPIS is good, they used to be better. Now they made it, they try to quote the textbook answer. If you do your research, you'll get there no problem.

Skip the LPE stuff too, head right to comp cams and buy a set of AFR 190's or 195's on your way through....

Beach Bum

BBA,

In all honesty I truly wish you or anybody could figure out how to make a bunch more naturally aspirated HP out of the ported stock TPI components for the simple reason that whatever applies to the TPI is undoubtbly also going to apply to my Superram which also is a long runnered set-up by definition.

My problem with Big lumpy cams with the stock TPI... its been done, with and without good flowing heads, all it succeeds in doing is damaging the one and only strength of the TPI, and thats off-idle torque.

As I recall your proven set-up with a 350 and 400 hp is with a Carb and Dual Plane manifold, which by all means I agree can easily hit 400 hp with good flowing heads and a matching cam. I don't think anybody would argue with you that a carb set-up can easily hit just about any hp # you want provided you're willing to rev it, which there are a host of manifolds available to allow you to do this.... but a TPI is a completely different animal.

As a note, myself, Ralph and Bowtye8 all run fuel pressure fairly low... mine is at 42 psi this moment, Ralph is traditionally running down in that neighborhood too, Bowtye8 around 45 psi at last conversation with him. If I bump my fp to 45 psi or higher it'll run rich. I don't know what fp JD383 runs at.

Ralph has never dynoed, but he's in the neighborhood of 400 hp based upon known criteria.

Bowtye8 at last dyno was around 380 rwhp with his 383 MR ZF6spd set-up.... which is roughly 450 flywheel HP. You can see his dyno sheet from my webpage if you're interested. He has since went solid roller and a better set of heads and maybe bumped his injector size by now.... just got it together he's racing next weekend.

JD383, not sure if he has dynoed, but its an LPE motor he bought thats advertised at 440hp and 480 ftlbs of torque. They come standard with 26 lb injectors.

My dyno is below. based upon my automatic transmission I make somewhere around 362/.80 = 452 hp or 362/.825 = 438 hp... depending on which auto losses percentage you believe in.



In any regards, good luck on your quest, and be sure and share your results with us all.

cheers,
Beach Bum

My webpage: http://www.corvetteforum.net/c4/beach_bum/

BBA

Beach...Actually my setup was with Holley Projection and a torker-II intake.

BTW: Do you have the large port base manifild?
I plan to port match my stock base on the intakes ( to my Brodix heads ) and siamese the runner end of the base ( as shown on this and the TPI sites ) along with maybe adding siamesed runners...all to simulate a larger volume runner design, mostly to save money over buying the big base/slp setup.

The way I keep low end torque up, if you remember is by haveing very little overlap yet a large duration ( 230º-236º ) cam...lobe seperation is 115º Remember, with the TPI, torque projected was over 400 FT-LB's from 2200 RPM and up...I don't see a loss of torque anywhere with those figures :D

Again, seeing is believing, but my dyno proggy says it will make 439HP with TPI or 485HP with single plane, and power doesn't fall off on the TPI until 6500 RPM or so...I think I will have it from my combo.





[Modified by BBA, 11:57 PM 10/1/2001]

Beach Bum

BBA,

Yeah, I have an out of the box Accel base intake.

I don't recall ever hearing anybody running a 115 lsa and 230+ duration with a tpi, so I honestly cannot say what the results would be, but I cannot imagine how this will overcome the problem of the TPI simply not able to provide enough air to a 350+ motor above 5000 rpm.... I believe with these types of set-ups you can help keep the power from falling off so quickly above the HP peak of roughly 4400-4800 rpm, but its still falling off and the optimum shift points will still be down in the 5000 rpm area, keeping in mind with a 2000 rpm or so shift slap back.... you're still going to want to shift where your average HP is greatest for this 2000 rpm window.

btw, I think 439 HP out of the stock TPI components even though they are thoroughly ported on top of a naturally aspirated 350 is virtually impossible. I don't even think you could do it with aftermarket large tube runners and Accel or Big mouth base..... with Arizona speed and marine runners, you could probably get 380 ish HP out of it, and that would be a well balanced, great flowing heads, free flowing exhaust set-up.

btw, I once tried a Crane hyd with .467/.494 - 224/232 @ .050 112 lsa with my 350, Accel large runners, Accel base, ported plenum, 52mm tb, Hooker headers, out of the box Dart heads..... performance was very disappointing and resulted in low 13's timeslips. A change to a LPE grind was a huge improvement and quickly got me well into the 12's.

One other note, I notice you're obviously not a fan of the LPE 74219 camshaft.... if you can find me a better hyd roller grind that will perform better with a TPI or Superram 350-383 application.... I'm sold and I'll buy tomorrow, but I need to see proven results from somewhere. The LPE 219 is a fantastic street/strip grind that while moderate at best in the duration department, has very agressive lope ramps based upon the .560 lift (w/ 1.6's) The cam will also do a 50 state smog pass.

Regardless, I sincerely hope you can do it, if you can, that only means whatever you did could possibly apply to my set-up.

talk to you later
Beach Bum

BBA

I have the cam and heads already.

BTW: Did you mean the 224/232 cam was hyd or hyd roller? If it was hyd flat tappet, then I couls see 13's at best, as thats pretty close to the stock L82 Hyd cam whic was good for about 270HP max.

Of course my cam is a little stiffer than that...230/236 at .050" lift, which comes out to 290/294 advertised, and lift is .560 w/1.6 rockers. 115 lobe sep, 113 int cl. With the Projection setup, my dyno shows between 489-500 HP, with a darn near flat torque curve.

As for making the stock TPI base flow enough...I am going to siamese the heck out of it, use siamesed runners and a 52MM TB. I know the ports will be able to match my Brodix intakes, since I port matched the heads to medium chevy gaskets. I think the intakes are like 200CC. I have the flow sheet somewhere...but I havent seen it in about 6 years ( I flow tested them about 10 years ago, so where did the paper go is a good question ). Suffice to say this combo with a slightly milder grind ( only by a few degrees ) ran high 11 sec 1/4's in the 79 on street radials with a 2000 RPM converter. I imagine it would have done substantially better with the right converter and slicks...but it was a street car, not a drag car.

I may end up switching to a later model TPI ECM to get rid of my MAF obstruction...but that will be later down the road once it's tuned in and I know where the ecm settings need to be. So, the MAF may limit me a little on top end breathing...but I think the intake will be fine.

I wish I could just have all this done right now so I could come out with real results...but I'll get to it.

smallblock

well said Beach........ ;)