There seems to be only 1 guy on the entire TBI board that ran a decent time in a N/A 305 TBI on the fastest TBI thread, 14.2@96mph. Post times and mods, NO BS. I'm very interested in what a TBI can actually(timeslips) do.

 

wow not everyone at once

 

13.8/102mph(Oct 01)
2.195 60"/.7sec RT
3.07 rear/Stock Tires at 35psi
Xfire Corvette/4+3 Trans/Z-51
2.0" TB's(Now 2.13")
Comp Cams Hyd Rlr(Now using 1.6rockers)
TPIS Headers
TFS 23d Heads
MSD 6A
Ported and EH'd manifold
Stock Injectors(Now 80# Parallel Plumbing)
K&N Air Filter
All Emissions operational and passed Illinois drive cycle

 

what?

 

must be a vette cross fire

 

14.209 @ 95.5mph
ultimate tb
edelborck tbi intake
edelbrock centerbolt heads (60cc chamber, 2.02/1.60 valves)
roller tipped 1.6 rockers
edelbrock tes headers
no cat
borla cat back(open plate)
posi w/ 3.54 gears
2000 stall convertor(waaayyy too small to get the job done)
transgo shift kit

cam and chip were stock

chip woudl have easily put the car into teh 13's and spending all taht money on heads was a mistake, a cam woudl have been a much better choice.

later
tim

 

NJ Speeder : So would have gone with the LT1 cam??? or something different?

I hear that the S/R Torquer heads with the LT1 cam is a nice setup, but I can't confirm that. How was your daily commuting affected? If I could get into the 14's that would be sweet, but I don't think I can use that tall of a converter for my daily driving. One last thing....do you know anybody who would do the ultimate tb mod for me? I keep sending that Camaroracer1992 emails, but he never responds.

 

Don't waste your time on the " ultimate " TBI mods. They are worthless.

 

NJ Speeder, You said stock cam with those heads 2.02/1.60" valves? No problems with the big valves and the cylinder walls? I wonder how much clearance there was left, for a bigger cam.

 

vortec, care to explain? pretty ballzy comment. i'd disagree just from what i noticed when i did mine, but maybe you can prove me wrong

 

i agree camp....that was pretty balzy they worked 4 me

 

It worked for me too. :lala:

 

100% totally absolutely wrong.

Grinding the tbi, shaving the throttle shafts and advancing my timing 6* gave me .4 and 2.5 mph in the 1320 boogie.

I have time slips to back that up, too.

 

I agree, boo that man!!!

Ultimate TBI worked real nice...real nice.

 

My car ran consistent high 16s with the mods in sig and the ultimate TBI mods. Must have had something wrong with her...

 

ok, so i'm guessing he doesnt feel like justfying his response. but the ultimate mods are not a waste as everyone else agrees with. granted, on their own, they may not make much of a difference, but they'll help when you really start making other changes

 

I have yet to do the ultimate tbi mods and I'm in the 15's....

Then again I also built a pretty effective ram air setup to offset my lazyness in not doing the ultimate tbi mods...

 

Slade what did you do for your ram air setup? do you have any pictures?

Thanks
Bill

 

You can push 2.02/1.60 valves on a 305 with around .600" lift. I've mocked up a .030" over 305 with 462 2.02/1.60 heads before and played around with a few cams. Shrouding occurs (roughly) at like .560-.580" lift.

 

I think someone should make a

3rd generation timepost registry!

or something like this so that every time this question comes up, someone can just be like "check out the registry." It would be convenient to have altitude, 60', method (strip vs. tazzo/gtech) and mods. I would do this but I have no idea how to make a web page although I could make a spreadsheet in Excel that we could link to and store it on the web. I think this would be very helpful in showing what TBI can do and for how much money.

sorry I posted the same thing in two messages but it seems like such a simple thing could save so much time, just like Eric's website.

 

iroc22, you hit it right on the head. i didn't have the opportunity to mock anythign up, but i mesured the heads and compared it to the cyl bore before i bough tht eheads. it really works out very nicely. i do think that saying shrouding doesn't occur until 560 lift may be pushing it though. the turbulance created by the loss of spce will actually occur at lower lifts and cause a drop in intake charge draw. yes, you can go with a huge cam for racing, but for a driver i woudl try to stay below .500 lift, preferably below 480 with big vavles. the interference does not cause a loss of rpm or ability to make power, just a loss of vacuum that will call for a higher idler, poor idle quality, and can cause a loss of throttle response.
vortecss, the ultimate mods have been proven time and againto be well worth the effort. i personally gained a full mph of trap speed from my first tb(which was very pooly done). teh tb's i can put otu now that i have practice are prolly worth a lot more(i have done about 20 of them)
gunny highway, i wodl have liked to find a LT4 cam(a little bigger tahn teh LT1 cam). the LT1 cam will certainly get the job done though, it is a proven piece and shows a big gain every time. you can go with more cam too. a few guys have messed around with zz4 cams and other grinds intended for a bit more rpm with great success. just remeber, teh bigger the cam the more time you are gonna spend working on getting eth whole power band right. with the stock heads or aftermaret small valve heads you can easily get into teh 520 lift range and keep a good idle under 750 rpm.
the car drove pretty good mos tof the time. since i didn't have a chip the car ran rich at idle and loaded up a bit if i sat in traffic. teh idle was pretty good and mileage stayed aroudn 20 on the highway.

a few things i woudl liek to see everyone look out for in all this though.
1. et is abotu teh car, mph is about the engine. all the power in theworld is worthless if you don't hook. the first time i went to the track with this set up i went 14.8's. i got a set of hoosiers and went 14.3 the next time out. 14.2's cam after messign with teh base timing and fuel pressure.
2. teh ecm is the key to a happy engine. if you can keep the chip tuned to waht you have in the engine, even if the engien is stock, you will see a huge improvement in power, throttle response, and mileage. you want a real custom chip, not some off the shelf or mail away junk. you can not tune your car from a chip company submission slip, you need to data log and adjust from there.

later
tim

 

You know, you are probably right. Like I said, it was just a mock up and there was no dyno tests for the heads. So shrouding could occur at different lifts.

Hey I'm no expert

 

Ummmmmm, I had a 14 second TBI Formula without the "ultimate" mods.

It's all in your head timeslips or not, The flow characteristics of the TBI base are really messed up with these mods. The mods to the blades themselves may work but grinding the flow vains on the top is a bad idea. These direct air into the TBI base. If you remove them the result is crossflow turbulence.

 

vortecss, i don't know where you are coming from on this one. what othe rmods did you have on tha tmotor? did you try that eengien with an ultimate tb?
unless you have made before and after comparisons on the same motro you can't even begin to think anyone is gonna buy into what you are saying.
i have seen my car and several others before and after ultimate tb's. i can tell you for a fact that a stock or very mild(exhaust/air cleaner) LO3 will gain a whole mph of trap speed from it.

later
tim

 

I would like to see some other combos, but I can get a stock TBI to modify and I will post before and after times after i do it. The car is running 15.7 @87 mph with stock t/b on down to the cat. K&N filter and hooker 2 and 1/4" exhaust to 3" later. Looking for mid 15s with custom chip aka coolant temps in the less than 200* range instead of 220+ like I've been running

 

Beast do you have Hooker headers or the stock manifolds?

 

Well my name is Cody ring any bells?

I was the one who did all of the "duh" mods on my 1991 Formula TBI 5-Speed and ran a best of 14.9

And yes I have seen several variations of TBI mods at the dyno three months ago. It was an engine dyno too.

The only things that the "Ultimate" TBI mods did was throw off the powerband characteristics. And limiting top end power.

These tests were all performed to prove a point that some "mods" aren't really mods at all. We also tested the air foil, GM TBI Vortec kit and the larger TB's.

By the way the GM TBI Vortec kit had amazing results!!!!

 

yeah a LS1 running high 16s WTF

 

GM TBI Vortec kit....what's that? and where would I get one?

 

everyone here can ignore anything vortecss has to say. he has been caught in lies several times before and is not known to bring anything constructive to teh board.
goodbye again cody.

later
tim

 

The stock manifolds and cat. 2 1/4" lol it's pathetic compared to the 3" on my T/A

 

and..............

 

I asked him what he was runnin. Beast you gotta get that exhaust outta there.....

 

yeah I know, but i have a free set of edelbrock's, 3" cat and hooker cat-back sitting in NY in my other car that I'm going to swap during winter break.

It sucks having one car with a blown up 305 sitting in NY and me living in FL right now.

My plans are to take the exhaust mentioned above, the TPI heads(home port/valve job) 1.6RR, I think a LT1 cam, (crane 2032 I think is a little big, although it worked well in my TPI w/o a custom chip) I haven't decided which intake to go with yet the TBI(edelbrock) or a carb w/ adapter. This car WILL remain very streetable, A/C, some emissions, my T/A was still a daily driver, A/C, full emissions, but I wouldn't want someone else driving(no power below 1500 rpm, hard brakes near idle, etc.)

 

What's the difference between the TPI heads and ours? I wasn't aware that they were interchangable?

 

someone correct me if I'm wrong, but I'm pretty sure that TBI heads have a hump in the casting to induce swirl(kill flow) and more than likely weaker valvesprings(mine are aftermarket anyways)

 

Hey guys, ok i just ran my car about a month back, i ran a 14.16 at 96mph with a 2.2 60ft, but then again my car is a 350 tbi, so i dont know if all my info is relevant to this thread, all my mods are posted in my sig. I think i can hit 13's fairly easily in better weather, and with better tires, the ones i raced on were really bald.

 

Yes they have huge valve shrouds that hinder flow big time. They have nice big valve openings, but that doesnt make up for the cast in swirls and valve shrouds.

 

Can those be removed by a machine shop?

 

jc92camaro are you using a custom chip or stock? The heads are the stock ones that come w/tbi crate I assume?

 

Im using a 8746 computer with a custom burnt chip i had done by brian harris, he is on this site, and he is pretty ***, he will work with you on getting a chip done to your specs. The car might not be perfect, because it will never be perfect without data logging it, but he made it run a ton better, and i was very satisfied. The heads are just the stock L98 heads.

 

Doubt it. Water jackets extend down and might be run into. The cast in valve swirls might be removed (I believe a member here tried to eliminate them) but the shrouds cant really be eliminated.