Dewey316

You are not listening. Here, I'll try it a little slower.

L B 9 ' s, I h a v e d y n o e d m a n y o f t h e m. W i t h b o l t s , T h e y a l l d y n o 2 0 0 - 2 2 0 H P.

You got that, don't do the BS of adding up 5hp for air filter, 10 hp from spark plugs and crap like that. I've seen it a million times. Of couse, a L03 with the same stupid waste of money bolts ons, is going to be in the 160-180 hp range at the wheels. That is not what we are arguing, because they have ... wait for it... diffrent cams from the factory. You put the same L98 cam that the G92 LB9's got, in a L03 (hey guess what, the specs are darn near the same as the LT1 cam), and you are right in that 220-230 hp range.

Now, Keep listening, here is where all comes together.

Since to really go much beyone the 220rwhp mark with a LB9, you HAVE to buy a new cam, and one that is bigger. Guess what, you put that same bigger cam in a TBI, your going to get (I bet you can guess now), just about the same HP.

Here is where the whole argument henges. TPI by its nature, starts to restrict itself around 5000rpm, so when you go with a cam that makes power to 6k or 6200, so that you can get your 300rwhp 305, you are working against the TPI's helmholtz tuned power range (crap, I used a big word, sorry, you can look it up, it might enlighten you). So, what do you do, you have to spend money on a HSR, MiniRam, SuperRam, etc. This is where my whole money argument comes in. The minute you have to buy one of those port EFI intakes, you just spent a huge amount of money, that you didn't need to on TBI.

And, I don't care how much money you spent on your car, That doesn't mean you have any idea what you are talking about, or that your point is valid.

And the fuel pump is an issue on every one of these cars, be it LB9, L98 or L03, again, if your going to make power, no matter which car you choose, that is going to be done, it isn't something that ONLY the TBI cars have an issue with, the pump is virtualy the same. YOu also realise how pumps work, and are measured right? At lower opporating pressure, they flow more, than the same pump at a higher pressure.

Now I freakin' remeber why I stopped posting on TGO, it is stupid crap and nonsense statements like this. I'm going to go back to little corner of the interweb for a while again. Its been fun guys.

thomas1976

Hey wait! Wat heads are eccellent up to 5000rpm, bolt right up to my LO3 and allow me to reuse the 3704 tbi performer with stock egr? I have installed the lt1 cam.

Dewey316

You have a lot of options, if you are willing to slightly elongate the center mounting holes, 416castings would work, the 305 TPI heads would work. The key with any stock head, is to do a little bit of port work on the intake side, and really work over the exhuast side. And I would port-match it to the manifold, so you get a nice smooth transistion. For only going to 5k, with the LT1 cam's lift, you don't need that large of a intake port. Your gains will be seen from smoothing it out, and opening up the exhaust side. Even my stock swirl ports, compared to the heads I have on now, I really didn't pick anything up until almost 4k rpm, you can go a long ways if you are willing to do your own porting work. The biggest hold up of running a 305, is that you need a 58cc chamber, and you are pretty limited in valve sizes, even a 1.94 valve starts to have some shrouding issues.

There are a couple of pretty good threads, with flow numbers of a bunch of diffrent heads. Pretty much all your stock castings are going to have their drawbacks, just don't be afraid to do a little porting work yourself.

--John

thomas1976

Thanks for stayn, ok what is the best head i can buy. Were I live if I need to have machine work done to heads for little more $$$ I can import e new engine.

I decided I was going with EQ-CH305A, but then if I do the math heds+manifold and stuff to plumb egr (and dont even know if I can plumb into y pipe) an aftermarket that allows me to keep stock egr and intake maniofold will cost me less.

There must be one, at least I hope.

I also read S/R are better then ported stock heads, somewere on tgo.

robertfrank

iTrader: (27)

Read both #10 and #11 posts in this thread for a run down of the most popular head selections here in the TBI world.

Dewey316

Considering the prices of buying new, I would almost say, just get vortecs, and a vortec manifold intake manifold. ANy machine shop in europe, can do the decking needed to cut them down to 58cc, that is not anything that is chevy head specific or anything.

--John

thomas1976

Thanks robertfrank, I missed the 53cc trick flow, but were the hell can I buy them? I only found 56cc.

Will the 305 S/R's be better then ported stock's below 5k rpm?

Dewey316

Its really hard to say how they are going to react at the lower RPM, the valve size and port shape have a lot to do with that, along with chamber design.

Vortecs are pretty easy to find over here, shoot, you find me an Audi S2 or RS2 front bumper from that side of the pond, and I'll find you some vortecs.

Fast355

iTrader: (2)

I have a 305 TBI that went well into the 11s too.

The 350 setup ran 14.60s in a 1994 GMC Fullsize Van.

Fast355

iTrader: (2)

Do you realize they made that much power using the stock ECM with tuning, the GMPP Vortec TBI intake manifold that supports EGR, a header system that I would not let near my car/truck, a restrictive exhaust setup, and a 46mm TBI. A single plane intake, a 2" bore TBI, better headers, and a less restrictive exhaust would have netted them ATLEAST 30 HP more to the wheels.

80smetalfan

With runners on a 350 motor, what you're saying is true. TPI was designed for the 305, however, and I don't think that runners or HSR is a neccesary mod for LB9 people. To further make this a spotty issue, there's the fact that some LB9/5 speed cars came with the L98 cam and have a 60 hp edge on an L03, as well as almost 50 lb-ft. I don't think that $1000 on a L03 vs. $1000 on the factory 230 hp LB9 would be a runaway victory for the L03. There are plenty of cheap or free mods for the TPI, just like the L03.

I disagree about the LG4 comment as well. If you have an LG4, you've either got a later model with similar compression to a L03, or you're a set of pistons away. Beyond that, really the only difference is the slightly inferior 416 heads and the fact that you don't have to do any computer tuning. A factory Quadrajet can support quite a bit more than you could throw at with any built 305. mw66nova has a pretty fast build that could be replicated with an LG4, but he uses a Holley DP, not a Q-jet.

Street Lethal

iTrader: (16)

Pretty sure Fast355 has Matt beat as of right now, Matt didn't break into the 11's yet....

Edit: Unless you meant currently active 305's.....

80smetalfan

Yeah, you're right. I read that thread a while back. It was like his friend or brother's car.

camshaftxe

Your probably right, but imho, what you and dewy have done with your tbi setups, and tuning is more then most can do, I dont think either one of you are crediting yourself enough for what youve done. Truely there are only a handfull of people that can get a tbi past 300hp without n2o. Its ALOT harder then it sounds, and a bit more expensive too. I know dewys probably pissed off at me because it may have come off as another bs induction vs. induction, but thats realy not what I meant. I just want you both to acknowledge what youve done for what it was, and try not to let these young guys be mislead in thinking its easy to mod an lo3, or professionaly tune a tbi by themselves. Most guys that come on here asking for good advice about building an lo3 realy dont know what theyre getting into. Cam swaps, intake manifold swaps, ultimate tbi mods, fuel pumps, and mainly tuning, these things all take careful calculation and in most cases a fair amount of mechanic experience.

89RS_82Z

iTrader: (2)

look if the guy wants to mod his 305 TBI let him its his motor and his car, he aint telling you what to do to your car, if you aint going to help him than dont post

just an FYI
670 CFM 2BBL TBI can handle 275HP
go wild and a 900CFM Holly 4BBL TBI can do up to 575HP

TADailyDriver

iTrader: (8)

Actually to tell ya the truth i dont even believe the slip because i find it kind of fishy. The people in the tower have been known to get car numbers/lanes messed up. The other car which was a 95 camaro, his slip said something along the lines of like 14.899... so even i wont go by the slip that i recieved, but i still stand by everything else i say. And im only standing up for fellow L03 owners who dont have the time and money to put a 350 in. we are only working with that we have and can do at the moment.

Fast355

iTrader: (2)

The Holley 670 is limited by its smallish injectors and the low fuel pressure they can tolerate. If you take the 670 TBI body and add on a GM pod, running around 35-50 psi, you can easily support 450+ FWHP.

Changing the in-tank fuel pump to a TPI pump is not very hard or expensive, just takes some time. Once you have the TPI pump, you can install a XtremeEFI regulator, opting for the high pressure spring when you get it. It will allow you to adjust your fuel pressure to 45+ PSI. The stock injectors will tolerate up to 70 psi reliably. An Ultimate TBI moded stock TBI running 30 psi will support 325 flywheel hp which is more than most will ever need from a daily driven L03.

If you have a laptop, the EBL Flash is cheaper than most carb/distributor setups and can completely handle ANY TBI setup. It doesn't require buying chips or a burner either. It even has its own datalogging equipment and software.

thomas1976

Some pics to show what Fast355 is talking about.
DIY modifying the FPR into a AFPR can be done easely. TB dosent need to be removed from the car, just the part with the FPR.
The smaller spring is the stiffer one not sure if 5-25 or 17-35psi (probably 5-25)psi and the taller one LO3 stock.

DM91RS

was sind dejenigen komisch worten?


Tell me if I was anywhere close


Back to the tech........Ich need the stronger spring. Where did you get it Thomas?

thomas1976

You would feel somwhat bewildered if you came to switzerland. We have 4 national languages, gearman, french, italian and romantsch (over 1000 dialects but we will not count them). A Swiss that doesent understand english is rare

The stiffer spring came with the AFPR from xtremfi but with that seller you newer know exactly what you get, his statements are most
Dont buy his tbi gasket kit the diaphram u get is not the one he illustrates and is not the right one for our application.

DM91RS

Thanks for the info on the spring and as far as the languages I sux as I can barely speak so called english..........


I did work with a Swiss ME at work until he quit. I could not understand him for shet. BUT....when you think about it he COULD speak English and my Deutsch sux....very limited