I'm thinking about porting out my stock TPI intake. I'd like to port the plenuim. Then new accel runners. Also I was thinking about buying a Throttle body foil. I heard the most restricktive part of the TPI system is what i getting ready to do. Does anyone think that i should buy a bigger throttle body and should i also port the lower intake or should that be good. I''d like to save money so ram intake are two much for me. Also if any could tell me what kinda power i'll make HP VS torque these applications. BTW i can reprogram my chip with tuner cat so I'll be ok on the chip side of things. thanks alot this is all on a 1988 corvette

 

:-)

All of this has been covered many many times in the appropriate board. Its all there waiting to be discovered again.

thanks and later
Jeremy

 

Sorry to bug you but I've looked around the TPI boards and could not find anything on Porting an intake. Can you point me in the right direction please.

thanks

 

https://www.thirdgen.org/newdesign/t...meseport.shtml

 

how heavily are you talking? i just finished some light porting on my stock intake. are you keeping the egr on it? if not you should take down the egr walls right after the throttle body openings. also kleen up the sides of the plenum right after the throttle openings and the runner ports can be cleaned up a bit.

 

thanks for the help. Well what i was thinking is just light. I'd like to gain a little more power top end and still pass edmissions plus save money$$$. what i'd like to plan out is.

1.buy accel intake runners
2.buy a throttle body foil
3 gasket match the my pleium to the accel runners. I rather not cut out the egr paths for edmission(unless it still passes?) but i think the area right inside the throttle opening can be ported or smoothed out.

My questions are.

1.) Is my throttle body stock going to be ok for this light mod?
2.) Is my lower intake worth pulling off and port matching to the accel runners and the heads. ( i heard most restricktive part of the TPI system is what i'll be porting?)
3.) should i leave my stock runners on and port those out as best as possible?
4.) Is there a good ECM bin file i can referance too, with this mod.
5.) did you gain pretty good power from it. I have a vette with 700r4 2.59 gear ratio and i spin out like crazy at less then half throttle on take off, It's a monster outta the hole. so i'd like to gain some of that torque at top end.

My next mods would be full exhaust headers back with high flow cats jump from 2 1/4 to 2 1/2 tubing. then later down the road a 383.

thanks again

 

hmmm welll quite honestly i have been looking at what you are talking about doing to the intake and i was wondering about how much you are looking at spending. because ( im sure you hear this a lot) looks about 300$ for all of that but for 600$ you can get an HSR and never have to worry about the intake again. it will work well with the exhaust you plan on and also you wont have to replace it down the road when that 383 demands more air flow.

 

HSR is not emmisions legal though. HSR is not quite as much fun for part throttle driving either. I have both.

 

There are many problems with the TPI, but I'd look at:

Transitions from one point to another, ie: TB to plenum, plenum to runner, runner to base, base to head. As is, sucks isnt even enough of a description of how bad it is.
Opening up the center of the port in the intake base as much as feasible. Dont break through

 

yeah we all know and love the feeling of that low rpm torque and rosponce but its kinda depressing when she hits 4,500 rpm and falls on its face. id be nice to keep pulling. and as one guy put it, " our cars have a powerband lke a truck" kinda degrading but true. and for his future combination id recomend it. it sucks to have to buy things twice. allthough it sucks it has to be emisions legal.

 

I would sugest opening the base up some to match the runners. I opened each runner 3mm and matched them to the TPIS bigmouth gaskets.. There is more room for porting than many might think. You just have to be carefull not to take too much off in certain places. Particular areas have more room for porting so port more from there and just try to keep a uniform diameter. There will need to be modifications made to the gaskets to get them to fit and the runners will have to be matched to the lower intake. I have SLP runners so there is plenty of room for porting. Here is a pic of mine.... if anybody wants more close up pic, that can be aranged.

 

Quarter mile WOT times of the HSR have revealed faster 60' times than a TPI. However part throttle is better with TPI. I too think that going to 6,000 RPM is great, and I loved the HSR for being able to do that. But than I thought to myself, I only really took it above 5,000 RPM a few times a month. Really, how often can you slam on the gas and hit 6,000 RPM in traffic and be safe from injury, damage or laws? So, it is your realistic driving habits that you need to buy for. Not bragging rights or such.

 

yep yep i'll be porting away soon. Wondering if the accel runner or the slp would be better and or if i should get the throttle body foil??

 

I have an well 5 TA's 4 of which are TPI 2 MAF and 2 MAP Those little EGR walls behind the throttle plates will not effect you being able to go thru emissions I just had to take my 87 thru the first week of march basicly 2 weeks ago and I ground those walls down flush with the rest of the plenum so it is a smooth transition from the throttle body into the plenum. It sailed right thru emissions.

So if someone tells you don't remove them for emissions purposes well they don't know what they are talking about!

 

Im willing to sell my air foil if your interested

 

I got and still have a throttle body airfoil. saw no difference in performance.

Now don't get the wrong idea I am not saying it didn't make a difference but if I am putting parts on my car I would like to be able to tell it had a positive influence

 

Knocking down the EGR walls won't make you fail emissions... I passed without the walls, I ported that thing pretty good in the front.

 

Yeah i heard that air foil setup is worthless with out porting. Thanks for the offer on that foil but i might just stick without it for now. So the EGR wall right behind the throttle opens and the 8 pleuim opening where the runner adapted is really where i should port. Cool sounds easy enough. hopefully the next coulpe weeks i'll be porting away. I'll give an update soon. I'll probaby take it to the trak before and after and post it.

thanks everyone

 

Oh BTW, them are a nice set of TA's After porting did your 1/4 mile times change for the better if so about how much? thanks man

 

Little more info for ya.

https://www.thirdgen.org/techbb2/sho...hreadid=237709

 

Thanks I actually don't have the black 84 anymore. Just sold it but Did pick up 2 87's. As Far as 1/4 mile times honestly I could not tell an indidual difference cuz at the same time I added a cold air intake 1.6 roller rockers, Tri-y headers, 3" cat back, MSD 6AL, Coil, 8.5 MM wires, and an air foil