Hey, I have a 350 to build for my car. How much power have you gotten from using the stock or ported tpi manifold, runners and plenum? I want to know how far I can go with the motor and other stuff before the stock/ported tpi setup becomes the bottleneck that restricts my power. I am hesitant to slap down $1300 for a mini-ram unless I need to. I would like to push the stock tpi setup to the max first. Id like to get the same power or more than a new vette, but I dont think its gonna happen with stock tpi.

 

If you port the plenum and base and replace the runners with slp and port and siamese those in as far as you can you will be able to support very nice numbers.

It's all about the cam and heads

 

3.8TransAM has a stock 91 GTA 350 that dynoed 225hp to the wheels with only a custom PROM. Whoah......Yeah GM, 245hp....sure.....I believe you. Really! Basic driveline loss estimates he has 280hp at the crank. On a stock car. Wow.

As far as being as fast as a C5 Vette, well. Thats a bit of work in and of itself.

 

In my sig.

 

Stock runners ported plenum ported intake TPI here all stock hardware there.

performer heads, XE262 cam

ran a 14.4 @ 94 MPH... in 2nd gear at 6400 RPMS (Way out of TPIs powerband) because tranny would slip if i tried 3rd gear.

So basically my car revved to 6400 RPMS bounced off the rev limiter then i let off and coasted the rest of the track..

so i figure if that time was legit thats at least 250-260 RWHP... and with a 2.3 60'time. if i coulda shifted....

I beleive its possible to put down 300-320 RWHP with stock stuff when its ported properly.. but thats just my beleif. im going to find out real soon though. good luck.

 

Anyone getting more than 300hp with stock tpi induction? I guess it sounds like no, thats not quite 1995 c4 power and nowhere near a new c5. No offense to anyone, but if i were not on a ******* budget I would have picked up a real vette instead of the poor mans version I have now. I just want to be able to run with the new stock musclecars on the street and keep up on a budget. I dont want to pull up to one of those dam new 13 sec turbo neons and get smoked, or worse, pull up against a grandpa buick like my other car and get beat. Unfourtunatley my old man riviera is still faster with only a performance pulley.

 

Hell yeah the long tube runner intake can do over 300RWHP. It can do 400RWHP. You have to really push the limits tho!

aftermarket base, ported to hell. slp runners siamesed in several inches, or even stock runners chopped and welded into fully siamesed runners. upper plenum hogged out runner entries, egr plates grinded away, throttle bore matched to throttlebody.

That would support awesome numbers with the right heads & cam combo. It's not impossible.

 

and for less than half that amount of $$$ you can just slap a stealthram on there and be done.

 

I find it so funny that whenever a discussion comes up about the LTRs potential someone mentions the HSR or the LT1... yet the topic wasn't "Cost friendly alternatives to modding TPI LTR setup"

The HSR, sure it's great but it has no EGR provisions. Neither does the LT1. The superram does, but thats about as much as a fully worked TPI setup, and the miniram, well... expensivo.

 

Crank or Rear wheel? I am ~280HP at the wheels. bone stock runners and plenum. With a 52MM TB, ported plenum and runners, and CAI i "guesstimate" near ~310 RWHP.


all this with the stock l98 cam

 

What exactly do you mean by "other stuff"?
The Stock TPI system only flows ~198cfm. That means basically a 400 flywheel horsepower maximum all things matched properly. That will not be enough to match the new Vettes. I also doubt you want to match parts to the Stock TPI, then switch to a Miniram or equivalent, and expect to achieve the results sought after.

Try Nitrous Oxide and as much exhaust flow as you can get.

 

Someone asked for "other stuff I already have" = chip, headers, no cat,adjustable fuelpressure, 9inch long k&n air filter, gutted maf sensor, airfoil for stock throttlebody, basicly no more improvments can be made to air intake until the throttlebody. I just want to get the most bang for my buck, keeping stock tpi costs 0$ vs buying new stuff. I have no useable heads (so I plan to buy new) and I am not willing to spend $ on stock castings when I could buy better flowing aftermarket ones for a little more. The plan is to go with a aftermarket cam and head combo that will probably put out too much for stock tpi to flow...am I right? Scoggin Dickey sells a kit with vortech heads + stronger springs and a tpi/vortech bolt patern intake manifold for around $1300. That might be a good start at a reasonable price, compare....$1300 also gets you a miniram setup but with no heads! My question = is the vortech manifold going to flow better #s than the stock tpi manifold (assume each manifold had heads that produce the same)? Anyone got the scoggin dickey setup yet?

 

Oh. The SDPC base will outflow a stock TPI base, but not much. The real advantage, is the material available to port. With a stock TPI base you can only go so far. Where as a ported stock base doesn't hold a candle to a ported SDPC base.

I have no idea exact CFM numbers but I imagine a ported SDPC base would outflow a ported stock unit by at least 40CFM.

 

HMMM, how might the scoggin dickey manifold flow compare to lets say the tpis big mouth manifold. I am not afraid to do porting. I dont think I would consider either one for the price unless they gave a good flow increase. heh, you can call me cheap if you want.

 

*SORRY ABOUT CAPS*

I WOULD HAVE TO BELIEVE THAT THE SDPC INTAKE WOULD FLOW SIMILAR TO ALL OF THE AFTERMARKET BASES, AND ALSO PROVIDES THE SAME PORTING POTENTIAL AS THE OTHER AFTERMARKET MANIFOLDS. BECAUSE OF THE VORTEC PORT SHAPE, THE SDPC BASE MIGHT BE INHERENTLY BETTER, BECAUSE OF THAT PORT ADVANTAGE. BESIDES, IF YOU WANT TO RUN VORTEC HEADS, THE SDPC BASE IS YOUR ONLY LTR OPTION.

 

:yourock:

Totally agree..I find it hard to beleive that the SDPC isn't atleast as good as the other aftermarket intakes. IMO better because they work with the inexpensive but good vortec heads.

Everyone complains on how the SDPC is too expensive. Why spend $400 on an intake and $500 on heads when you just buy AFRs for $1200. Well the AFRs won't work to their full potential unless a higher flowing intake is bolted onto them.

So :

$400 + $500 = $900 for well matched setup or
$1200+ for heads that are choked by the rest of you intake...no brainer for me.

Add the difference between the 2 to get a set of SLP runners, and then the time to port&polish them and the plenum and you got your self a low 13 maybe high 12second combo.

Building engines is about a whole package not just one component, and the stock components can work well if matched up properly to the right head/cam combo.

 

Thanks for all the ideas and info. It sounds like the stock manifold and runners are the weak links now in my intake combo. I now plan to replace the manifold and runners with better flowing aftermarket ones. As long as I have the potential to run with a c5 vette and beat a new turbo neon I will be happy.