TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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super rod can be found at giant eagles or other supermarkets... also media play.... barnes and noble doesnt carry it, at least in pittsburgh they dont... but ill put a scanned copy on TGO 2night... "GO STEELERS !!!!"
The heads used in the TPI Shoot Out were Trick Flow 23-degree (not Twisted
Wedge), and were installed with no porting on the 383 test motor.
Wish I had more questions, but I didn't at the timea s I have yet to find the damn rag around here.
I did get an email addy to send questions, and they will try to answer any we have IF we don't bombard them and we don't ask repeat questions etc.
I'll hold off questions until I can read the article.
If it is a lot of text, I have good OCR available to me. Do some decent res (300 dpi) and you can email them to me. I'll convert them and post the text.
If a lot of sidebar stuff... I'll take whatever I can get.
Originally posted by Red Devil Got word back on the heads.
Wish I had more questions, but I didn't at the timea s I have yet to find the damn rag around here.
I did get an email addy to send questions, and they will try to answer any we have IF we don't bombard them and we don't ask repeat questions etc.
Another thing that the shootout shows is that the TPIS/ASM LTR stuff walks all over the Edelbrock LTR setup. I'd still rather pour molten lead into my ear than give TPIS my money though. I'd just find the stuff used
got bad news guys... cant down size em' enough to TGO requirments.... any suggestions????? i have a dell scanner and each pic is aboout 650k to 740k...... is their a way to save them smaller without cutting off the edges of the page???? BTW, im using dell's paint program (sucks...)
TEN TIMES THE TORQUE
The Ultimate TPI Shootout
BACK IN 1985; CHEVY INTRODUCED THE WORLD TO A BRAND-NEW FUEL-INJECTION SYSTEM. DESIGNATED TUNED PORT INJECTION (TPI), THE SYSTEM WAS A RADICAL DEPARTURE FROM THE TRADITIONAL CARBURETOR PERCHED ATOP AN INTAKE MANIFOLD, OR
EVEN THE SHORT-LIVED CROSS-FlRE INJECTION SYSTEM THAT FEATURED A PAIR OF THROTTLE BODIES THAT DISPENSED BOTH AIR AND FUEL.
By contrast, the Tuned Port Injection system featured individual injectors positioned in the manifold base directed into each cylinder-head port entry. Unlike a carburetor or the fuel-dispensing throttle bodies used in the Cross-Fire system, the individual-port injection ensured even fuel flow to all eight cylinders to maximize performance and economy. The lack of fuel flowing through the intake also minimized oroblems such as fuel pud-
dling and helped reduce emissions. Many thought the advent of the sophisticated fuel injection had once and for all put an end to performance as we knew it. But the reality is the TPI-equipped engines started the current EFI performance revolution we currently enjoy—with the LSI and (soon) the LS2 configurations.
Although the L98 TPI engines promised improved fuel distribution and economy, the real trademark of the systems was their long-runner intake configuration. In the world of induction systems, long runners help promote low-speed torque production. While we all brag about how much horsepower our engines make, the cold, hard reality is that it's the torque curve that slams you back in your seat and brings a smile to your face. It is also what impresses the person in the passenger seat every time you stomp on the loud pedal. Chevy engineers were obviously shooting for an impressive torque curve when they drew up the TPI systems, as the long-runner intake design gave the small-block Chevy some serious grunt. Never mind the fact that the same runner length that provided so much torque actually limited high-rpm breathing—stepping on the gas of a well-tuned TPI small block immediately brought a smile to your face. Sure, the later LT1 engines offered more peak power, and ulti-
I had no problem finding the mag the first place I went to was tog****tis I mean tognattis but they didn't have it but they never have anything then went to tower books the had about 10 and I bought 2 and gave one to a fellow tgo member
__________________ Terrell
Quote:
road&track magazine October 1986 To sit in the Camaro and look out past the purposeful dash, over one of the most sensuously curved hoods in existence, is a treat
1990 Firebird Formula Procharged :350 in the works:
1986 Camaro Z28 Iroc-Z :Garage Art:
2006 GSX1300R Hayabusa Limited
well it seems that if the Big Mouth setup makes only 20hp less than a Superram, i think i will stay TPI LTR and gain that extra advantage of Torque!!! i mean lose 20hp and gain 30Lb-ft and easier installation of the TPI LTR setup over superram, not to mention it can be a bit cheaper too.
Thanks for posting this Ominous! Great article, good details, and very interesting results. What's funny is on a cold day my 355 is making the same power as this test engine. I have 28 less cubic inches, a smaller camshaft 224/30 Extreme camshaft but using 1.7 rockers, and factory PCM tuned by myself. Last time I dynod the car it was really cold out and my uncorrected #'s were 409rwhp and 441rwtq which equates to a 481hp and 518tq at the flywheel using a 15% loss for standard trans. I still have a little more to tweak out of it. I'll keep my SuperRam!! I've tossed the idea of going to the HSR just for testing, but probably never will.
Originally posted by Orr89RocZ well it seems that if the Big Mouth setup makes only 20hp less than a Superram, i think i will stay TPI LTR and gain that extra advantage of Torque!!! i mean lose 20hp and gain 30Lb-ft and easier installation of the TPI LTR setup over superram, not to mention it can be a bit cheaper too.
Your missing the whole point.
You need to look at the Superram graph where the that big power hump exists over the 450hp mark, it starts at 4700 and ends at 6100.
The LTR setup never crests the 450hp mark in that range. The only reason it hits 460 at 6000rpm is a final tuned event that occurs late in the rpm range, well after the power band has leveled off, the LTR power is essentialy flat from 4700-6000, when the final little peak blips in.
If you roll in a street car that doenst see trck time then it doesnt matter. If you are building your car for ET and MPH then having all that additional HP late in the curve makes a big difference at the track.
If you run any decent aftermarket stall converter, all that extra TQ the LTR setup makes under 4000rpm will be lost in the shift recovery between gears.
So if you plan to run the stock converter, then the LTR is for you. Otherwise the low RPM TQ is gonna be lost.
Just kinda how this stuff works out in reality, on the street and at the track.
well i got 2800 stall that should open up to 3100 with more potent engine. thats about all i need to run.
my point was that the runners for superram are so much shorter and flows much more than LTR huge length runners and only did a bit better for high rpm power which is expected but the gain doesnt seem to justify the cost of superram and installation. i only plan to run up to 5000-5500rpms and looking at the power numbers up to that point, it seems dead even in power but more torque for the LTR big mouth. seems to be the best setup for my needs, which is a street car. LOL
