Not sure if this is the right forum but... have any of you guys replaced your intake, runners, plenum and TB with the large bore package from TPIS ?

I just got off the phone with them and they tell me it is all a direct bolt on factory OEM type replacement. All bolt holes line up and all pieces will fit no problem, etc.

Well what else would you expect them to say ? Also, they claim my LB9 5-speed will see about 35hp and about 40lbs torque from this package. It is completely stock (well other than a cold air setup) at this point in time. I was going to install headers at the same time.

They want BIG $$$ for this bolt-on package. I would like to try it but would prefer to hear from the 3rd gen site first.

Anyone have any comments ?

BTW: I know I could do heads, block swaps, etc but I have a very low mileage 305 and plan on running it until it wears out so no 350 swap and no head swapping.

Thx in advance,
RP.



------------------
'91 Formula Firebird G92,WS6,5-speed,3.42 a ton of fun to drive.

 

Replace 19lb 305 injectors with 22lb 350 TPI injectors, to save money put SLP siamesed runners ($219) compared to $400 TPIS runners. The TPIS big mouth base is a nice base. Then port the upper plenum yourself, add a 52mm Throttle body (Holley), add MSD ignition and get a custom chip burned from www.fastchip.com

------------------
1991 Z-28 350 TPI, 700r4 with B&M shiftkit, 2400 stall, B&M Console Megashifter, 4th gen power seats, MSD6A, Blaster2 Coil, Holley 58mm TB, Ram-air, MSD 8.5 super conductor wires, Flowmaster catback, Crane rollers, march pulleys, and all free mods. (Currently in body shop getting fresh paint!!) I miss her! =(

 

I agree. For the price of all of that stuff you could likely have a Miniram on that 305!! To keep cost down, I would stick with your stock plenum and just port it yourself (there is a technical article on the procedure on this site) for free..... The SLP runners will also likely be just as good (and give you lots of room to work with as far as porting goes) as the TPIS large tube runners and are much cheaper as stated above. But they really aren't a necessity with an otherwise stock 305... The Big Mouth base is also a very nice piece as stated above, but I am not really sure that it is necessary for a stock headed, stock cammed (or even mild cammed), 305. I would just do some port matching of the new runners to the plenum as well as matching the heads. The biggest restrictions on your system are the stock air box and the plenum so, since you already have a cold air intake, you will see the largest gain in performance from the plenum porting mod alone... The high end runners and bases are more for the modded 350s than a stock 305.... So I would say a simple free porting job on the plenum (per the tech article), port matching the entire intake system, and maybe the SLP runners if you really gotta buy something, should give you about the same results on that stock 305 as all of that TPIS stuff, IMO...

Upgrading to a nice header system will also help that thing breath a lot better and compliment any mods you do to the intake system... Just keep in mind that it all works together when you do each mod. So try to match any intake system mod with an exhaust system mod (and vice versa) and your results will be much more impressive...

my $.02

------------------
1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

 

I bought all those parts used: TPIS big mouth intake, TPIS large tube runners, TPIS 52mm TB, and ported the plenum myself. I added these parts, an LT4 HOT cam, and SLP 1 3/4" headers over a stock ported TPI intake, ZZ4 cam, and SLP 1 5/8" headers and gained 35 HP and 37 TQ at the rear wheels. I doubt you'd get that much on a 305, but they'd definitely help. I wouldnt pay their price for them new however.

------------------
1991 Camaro Z28
5.7L 5-Speed (originally 305)
317 RWHP, 418 RWTQ
13.23 @ 107.62 MPH (2.10 60')
Southern California
Member: SoCal 3rd Gen F-Bodies
Member: SoCal F-Bodies
-=ICON Motorsports=-

 

Replace 19lb 305 injectors with 22lb 350 TPI injectors, to save money put SLP siamesed runners ($219) compared to $400 TPIS runners. The TPIS big mouth base is a nice base. Then port the upper plenum yourself, add a 52mm Throttle body (Holley), add MSD ignition and get a custom chip burned from www.fastchip.com

I was just wondering what the 305 would get as far as power gains if I were to move up to bigger injectors and the other mods stated above. Also, at what point would it be necessary to move up to higher 22lb injectors. I have a 305 TPI that i plan to add ported plenum, slp runners, 212/218 dur at .05, .447/.457 lift comp cam, as well as headers and full exhsaust, and edelbrock ported intake base. With this setup, good idea to upgrade injectors.

 

Great feedback guys -- thx alot.

The reason I was going to install headers (1 5/8) is because it sounds like the manifold/runners/plenum/TB mods from TPIS (or any other vendor for that matter) are not optimized unless you help exhaust clear the heads. I wanted to replace the heads with S/R Torquers (305) which would REALLY make this upgrade shine but seeing as I have no money tree in my backyard the heads will have to wait. Good idea about the SLP runners. The money saved by going this route pays for a new chip.

Whether it is a 305 or 350 I can't help but think there will be meaningful performance gains by increasing the air flow through the TPI by about 22% (using the TPIS package).

thx, RP




------------------
'91 Formula Firebird G92,WS6,5-speed,3.42 a ton of fun to drive.

 

If you are running a stock 305, spending all that money for that intake is a waste of money. You will see very little gain for all that money. If you are keeping the motor stock why not just port the stock intake and spend the money you save on upgrading your ignition (MSD) getting a good catback, headers, pulleys, chip burning stuff, AFPR and so on..... dont forget SFCs either.




------------------
Bone stock blue 85' Z28 42k original miles.

*previous car: lightly moded 89' Formula 350

 

*********************************************
If you are running a stock 305, spending all that money for that intake is a waste of money. You will see very little gain for all that money. If you are keeping the motor stock why not just port the stock intake and spend the money you save on upgrading your ignition (MSD) getting a good catback, headers, pulleys, chip burning stuff, AFPR and so on..... dont forget SFCs either.
*****************************************

Do you mean the intake as in manifold / runners / plenum/etc ? That I will see very little gain from these mods ? That is a nervous thought -- investing over $1500 in parts that may provide little benefit in performance ? Have you tried these mods before so are speaking from first hand knowledge ?

FYI: the local speed shop (I am in Southern Ontario) has told me that if I give them $600 (USD) they will get me 40hp out of my 305 heads and as much as 60hp if they install headers with the head work. I always thought head work was something of a black art and I would be better off with TPI bolt-ons ? I am not speaking from experience -- I have never done TPI bolt ons before.

RP.




------------------
'91 Formula Firebird G92,WS6,5-speed,3.42 a ton of fun to drive.

 

I think what everyone's trying to get at is that without doing the heads and cam, all the TPIS parts will not perform at their advertised peak, especially on a 305. Keeping the port velocity up will give you the biggest benifits, ie cleaning up the plenum and port matching all the parts. For your application, bigger is not better. Save some money, do it yourself. Try some 1.6 rockers to get more air through.

 

Agreed! Just this year I put on an Accel base with a set of AS&M runners and mildly ported the plenum and saw very little if any gain and that is on a 350!
I'm sure they will pay dividends when a new cam and heads go in but until then it is basically worth not alot.
By the way where in southern Ont. are you and what shop are you refering to?
I am down near Windsor.

Bob

Bob

------------------
350 TPI, 700R4(rebuilt), K&N's, MSD 6AL, Headers, Flowmaster, 160* stat, airfoil, MAF screens cut out. 13.88 @ 101.18 mph

 

just do an archive search on bigger throttle bodies and that will give you an idea about TPI intake bolt ons. bigger is not always better, particularly in the case of a stock 305. a ported stock TPI is more than adiquate for an even mildly moded 305. and pretty much a waste of money on a stock one. i have actually heard of people losing power from upgrading the intake with out upgrading other components.

------------------
Bone stock blue TPI 85' Z28 42k original miles.

*previous car: lightly moded 89' Formula 350

 

I agree that heads and cam would be your best bet for performance upgrade. TPI was developed for a 305 therefor the airflow is vary good for a 305. You could do world products 305 torquer heads for $750 or have you stock heads ported by that local speed shop. do a cam for roughly $250 and port the stock intake and plenum for under $10 in bits if you have access to a die grinder. Hell you could get a coustom chip from fastchips and still be under $1500

------------------
89 GTA w/700r4w/stage 2 shift kit,2800 converter, corvette servo, B&M mega shifter, TPIS bigmouth intake, TPIS large tube runners, TPIS 52mm throttle body, Ported Edelbrock centerbolt heads,Accell 30# injectors,holly afpr,GMPP LT4 hotcam,CompCams Pro magnum roller rockers,Edelbrock headers, flowmaster crossflow muffler,MSD 6A, accell coil,150 shot NOS. My baby is going back togeather soon.

[This message has been edited by poncho9789 (edited November 13, 2001).]

 

Ok. I get the message. I think you guys have saved me alot of wasted time and otherwise ill spent dollars. I am going to put some of my TPI dollars into bits and a good drill instead.

I've read atleast a couple of times that the TPI was built for the 305 therefore it is pretty much optimized for the stock 305 -- atleast for what the factory was intending to produce in terms of power.

Prior to calling TPIS I was preparing to pull the heads and spend some pretty big bucks making the stock 305 heads work better (porting, 1.94/1.6 valves, 1.6 rockers, etc) and throw on a good set of headers. I had figured on spending about $1500 on heads and headers then heard about the TPIS package so got side-tracked.

Regarding heads I have read some about the S/R Torquers and other competition heads. It seems that the ones that work for the 305 mostly flow similar cfm on the intake with major gains on exhaust ports ? (Correct me if I am wrong just trying to get to the bottom of the matter). The speed shop I deal with says that if I bought S/Rs that they should get porting work done as well. Which leads me to think what the heck good are they if you have to have them ported anyway ? So I figured on building up the stock heads instead (atleast I know these will fit). AFRs and TFs are different of course, in a league of their own and in a PRICE range of their own. I can't or won't afford these heads so again figured I'd build up the stock heads instead.

BTW: 88 IROC Bob, I am in Kitchener and the shop is Rudy Held's in New Hamburg. Last I talked to them they said that if I didn't want to pay up for the S/Rs ($1300 CDN) or AFRs ($2700 CDN) I could have my stock 305 heads ported and polished with 3 angle 1.94s and 1.6s with 1.6 roller rockers for about $1200 CDN. (I don't have a written quote yet). They were adamant this would net me FOR SURE 35hp (low side) and much more (50+ high side) with a good set of headers for another $500. Sound right to you guys ? Now I know a cam upgrade would make a big difference here but I really do not want to change the cam.

I assume there are some tech pages here on porting TPIs ? Can anyone suggest a good drill set to use ?

thx, RP.


















------------------
'91 Formula Firebird G92,WS6,5-speed,3.42 a ton of fun to drive.

 

I agree what smurfnz28 said about the intake stuff. I know two people who bought the intake parts and put them on and ran the exact same. One of them put on bigger injectors and ran slower. he had to swap back to stock injectors. one of them put in cam and exaust and then got much faster.

FBIRD had a post with good porting info. sears sells a good electric grinder that is much better than drill, and highspeed carbide bits work much better than those cheap stones. someone else told me that dipping the bit in dishsoap while you are porting helps keep the bit clean and working good and it works. i just ported my stock iron heads this way. the grinder costs $100.



------------------
1986 Iroc 305 small block chevy getting modded now for speed

 

Another Canadian here. $1300 seems high for S/R heads. I bought my edelbrocks for $1400 CDN. I recall the S/R's were closer to $1000.

My thoughts are that a shop would rather sell you the rebuild and make more profit then selling you new heads. Call around.

I am running a stock base, runners, ported plenum, 52mm TB, airfoil, edelbrock heads, ZZ3 cam and a stock prom. It runs surprizing well. The heads made a big difference.

Definitely do some calling around and see what's out there. I recall I could get vette heads from GM for $1500. With the recent change in the dollar thou, not sure, might be more.

Mark.

 

World products S/R 305 heads are only $750

 

Thx guys.

The S/R Torquer heads are about $750 US which in Canada (home of the over taxed and overburdened) they cost about $1050 (tax not included) due to the difference in the CDN dollar.

Mark -- the $1300 for the S/R Torquers include tax and an allowance for porting. The speed shop seems to think they need a few hundred worth of work to make them 'flow properly'. having no experience with S/R 305 heads I couldn't say whether this is the case or not -- just what they advised. Their argument made pretty good sense at the time though.

I've heard that the vette ports have no ERGR crossover so would require custom work ? I was going to look into something called Vortec heads ? Seems quite a few are raving about these. Not sure if they fit a 305 or if they would improve anything ? I'm curious, did your upgrade to the 52mm TB actually improve performance ?

thx, RP.




------------------
'91 Formula Firebird G92,WS6,5-speed,3.42 a ton of fun to drive.