TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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there is some great great info in this thread and i dont want to see it get lost so im bringin it back up!! the only question i have is in all of the info that on here why is there non on the SLP runner setup? i wish i could find out how a set or ported slp runner would perform to all these others.....im on the hunt to push my 92 chevy reg-cab short bed 2wd truck into the 12s on a 355 with ported slp runners but just nto sure if it can be done....im still searchin for the right cam and heads that will still pass emmissions. any imput out there?
i Have the mini ram 2 mainfold and a .525/.558 lift cam and by god on a stock block it did wonders i also upgraded heads/ injectors/ throttlebody and much more you will se an incredible increase in horsepower and general driving ability. check this website out. wonderful guys that know what there talking about its www.tpis.com
i Have the mini ram 2 mainfold and a .525/.558 lift cam and by god on a stock block it did wonders i also upgraded heads/ injectors/ throttlebody and much more you will se an incredible increase in horsepower and general driving ability. check this website out. wonderful guys that know what there talking about its www.tpis.com
Check the aftermarket vendor review forum for some interesting threads on TPIS......
i have a LPE cam i like..it's a mech roller and a bit bigger then any you have listed..works fantastic. with my super ram & the old 383.
going to use it in the New 427sbc with the super ram.
LPE had this listed with there 420sbc with 406 fpt @ 1600rpm..lol and over 550fpt at 6000rpm.. never going lower then 400 fpt from 1600 to 6000rpm (Hp was in the 550 ball park) was a good cam in my LPE 383.
not going to use the above cam.. going with 246 248 @ 50 with a 618/620 lift mech roller in the 427 sbc (12.5 to 1 cr)
Last edited by articwhiteZ; 11-07-2010 at 01:14 AM.
Too bad that the article didn't say which heads were used, but the best I could figure is that they are discontinued heads. Still no idea which ones they were, nor would heads would be equal or better to the same specs, as far as similar type (low rpm/torque producing) results.
It says in here that they were trickflows not twisted, I believe it was page 3 or 4 also talking about emailing the writer for more info in the post
Edit.. Here it was at the top of page 2
Quote:
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.
Last edited by david068513; 12-06-2010 at 12:22 AM.
It says in here that they were trickflows not twisted, I believe it was page 3 or 4 also talking about emailing the writer for more info in the post
Edit.. Here it was at the top of page 2
Quote:
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.
Would have been nice if they did it with a stock L98 to show what differences it would make on a L98 as it came from the factory.
But, as to the other one, I do have the articles saved, so I can upload it tonight when I get home from work.
You should have seen my old motor, while now I'm building a crazier motor, dropping a 305 TPI in for the time being. Look at my 350 stock build up, sounded good, 8.43:1 compression, 87 octane, but the block cracked.
I was thinking they may have used the TFS 23 degree heads which are still available. However, they may have used the G2s like the ones I have. They discontinued these heads because too many people didn't understand how to use them or, more to the point, how to measure valve to piston clearance. With the ZZX cam(240/240 @.050, 560/560, 112LSA) Huge ported early Superram base, SSM large tube runners, 10:1 flat tops and 6" rods, this 355 is a beast. A long runner TPI that pulls hard to 6,800rpm and eats LS1s for lunch.
[Quote: Originally Posted by 89gta383The stock tpi intake is not 'pulling' to 6000 rpm. Just because it flatlines after 4500 doesn't mean it is still 'pulling'. Pulling would imply that the car is 'pulling' harder, meaning going faster, and that is not happening if the intake is flatlining. The intake is restricting airflow when it flatlines. ]
[Quote: I know this is old, but, sorry, I disagree. Just because the engine is not INCREASING hp doesn't mean it's stopped pulling. That engine is continuing to increase it's rpms (and therefore accellerating) at the same hp level. It will not have nosed over until that hp number begins to drop.
As I understand it, once you hit peak hp, the next relevant issue is where the shift recovery will place you in the torque curve. Ideally you want to fall right back into the torque peak, or just slightly below it. -30306 ]
.. I have to agree with 89gta383, just because the calculated HP number is staying nearly flat doesn't mean the engine isn't stopping pulling. When you're driving the car, the TORQUE is what is pressing you back into the seat/accelerating the car hard, and as the RPMs continue to rise, the torque is falling off fast, and at some point it doesn't FEEL like you're accelerating very hard anymore and it's time to catch the next gear and start accelerating hard again... by creating graphs off rear wheel torque(thrust) vs RPMs for each gear, it would be really easy to see at what RPMs it would be more advantageous to be up into the next gear as far as acceleration goes...
for those of us that value the info presented in 3rd gen but prefer TRUCKS, what is the best choice for mid range torque. have an 89 k1500, 5.7l, vortec heads, 700r4, 4.10, 31" tyres, 6000lbs, currently with edelbrock's tbi to mpfi conversion kit and ported tb flowing 640cfm- works well but always liked the TPI looks, but not the rpm limit, need to pull to 5500rpm. i like the engine masters competition thinking- its not the peak power, but the area under the curve. was thinking of the HSR but am afraid of loosing too much grunt down low. am going to use an engle hyd roller 477/479 206/212 @ 050-114 deg, too many problems in the past with low vacume and speed density.
.. Your problem with Speed Density (MAP) system wasn't "low vacuum", but that those rigid MAP systems don't automatically compensate for changes/mods like a MAF TPI system does! Notice the EFI systems in this thread were all tested with a huge 236/242 cam! (a little too big for trucking)
.. Looks like the Holley Street Ram or Accel SuperRam would make the BEST truck manifold! At least for a 383". Some of the long tube TPIs make more peak torque, but it's just that, PEAK torque over a narrow 300 RPM range. They're kind of peaky. The Street Ram and SuperRam aren't as peaky and stay strong over a WIDE RPM range with big HP. Which is what you want in a performance truck, strong torque pulling all the way through each gear, not just a strong peak over a narrow few RPMs range.
.. However, the "206/212 cam" you're considering for "5500+ RPMs" looks a little small compared to even the typical stock TPI 350" cam which I think most were around 207/209 duration... a 212/222 - 219/229 range or something cam would prolly work better for a (big tube TPI) HSR/ASR 5.7L Vortec headed truck engine with headers, freeflowing dual exhaust, freeflowing air cleaner, 4.10 gears... especially with compression ratio up in high 9's...
.. Looks like Super Rod Magazine folded up about 2009, but, fortunately, some of the links to that article on this last page still work. Such as this one:
.. Looks like Super Rod Magazine folded up about 2009, but, fortunately, some of the links to that article on this last page still work. Such as this one:
never going lower then 400 fpt from 1600 to 6000rpm (Hp was in the 550 ball park) was a good cam in my LPE 383.
1994 Camaro Z28 B4C, LT4 Conversion, 4L60E(being rebuilt) 3:23's T-tops, 350RWHP WS6 wheels,2000+radio, 
