Im trying to find out whos been successful with the TBI and centrifgual blowers. I have a 69' chevelle with a 144 blower on my 355 and its quite different than a centrifigual in fuel system department. I have alot of questions and want to make a kit for the crossfire injection 84' corvette. I have plenty of ideas and have funds. I have access to mills and fab equipment for custom TB housing.

Basic questions are what mods to do for blow-through on TB's and boost referencing a TBI system? What about a BAR 2 Map sensor? What do I do to make it work under boost,etc,etc.

If anyone can help a F-body fan,corvette guy and overall GM lover,Thanks in advance!

 

Mechanically hooking up the blower to the TB's is going to be up to you. We can help on the ECM side of things.

The ONLY way this project will have a good outcome is if you learn to tune your ECM youself, no way around it. Up untill recently there has been no good way to run boost with TBI. Some guys have used FMU's with limited success. Rbob has recently released the EBL system, it's basically an add on board for your stock ECM that runs his ultimate TBI code. This code is going to be your saving grace. It has provisions for running a 2 bar map sensor and compensation for boost referencing the fuel pressure. A couple of guys have used it with boost and report good results. You might want to contact Fast355.

For the TBI system itself, we've found that with two 2" throttle bores and 90 lb/hr injectors you are about out of air and fuel at around 425 to 475 hp. Since you'll be running boost and need a slightly richer mixture you'll want to aim towards the lower end of that scale.

Hope that helps.

 

I've heard of the ULITMATE TBI CODE but don't know of it and am new to tuning a ECM all together. The 82-84 vettes had horrible non-tunable ECM's and I would like to upgrade to a 7747. No saying that,the TBI tuning will be the hard part. The fabing of the system and fitting it isn't the major issue here but the fuel delivery and ECM like you stated.

Im not looking for over 400hp but that would be a nice number to hit. Realistically a 325-375hp range is doable I believe with 90lbers and 2" TB's running 4-6psi and minor motor mods,upgrades.

I have many concern's with this set-up like FPR must be boost referenced or does a tune/2 bar map eliminate the Boost referenced FPR? I know a 2.1 FMU could work but with not accurate tune in mind.

Also,What mods should be done to the TB to accept boost passing it? throttle shaft mods? Is there a write up on it somewhere?

Thanks for the help BMmonte

 

I have only ever seen one Cross Fire Supercharged set up. If I remember correctly...and its been awhile...the guy made a custom air catch box that both TB's were housed in. That's all I can remember....that and he spent a bunch of money on it...it was powerful if I remember correctly though.

I know you are a fan of the Cross Fire but...its just such a different animal. I would probably contact Turbo City and inquire about how much is attainable by just moding the Cross Fire set up and run it Naturally aspirated. I mean...overall...the corss fire was capable of only so much. Its design truely limits perf. So if by chance the set up can be mod'd to hit 350 or so hp...then spending all the time figuring out how to make it supercharged could be a waste.

Really man...I don't want to burst your bubble but there are truely a lot of differnt methods for getting that hp figure. I know how you feel though...I spent a lot of time figuring out how to get my Caprice TBI to be supercharged and got a kit and everything and then I was told by the engine builder that I want to build it that a TBI supercharged really won't move the Caprice as good as I would've liked it too.

In general...TBI supercharger kits are difficult to find nowadays...a few companies like Vortech and Paxton don't even make them for TBI anymore. Supercharged TBI's just aren't a popular choice for most people...that's why I haven't found anybody to buy my kit yet. Ithink Procharger might make one still...I don't know anymore.

 

John has a point, it's really hard to make less than 450 hp with any kind of blower. Unfortunately 450 hp is about the limit of what TBI can support. It's also pretty easy to make around 400 hp with just a luke warm cam and decent heads which will cost substantially less. You might look into what Ben73 has done with his crossfire setup.

 

400hp isn't easy to achieve with a crossfire intake manifold. a X-ram is more hp friendly but I personally don't like it. Sorry Ben and Jim but I don't like it.

I have a new Magnacharger 122cid supercharger on my 69'chevelle and ditched the weiand 142 blower just this week....what a difference in boost and torque! more power from a little blower and torque is out the @$$!!! I love boost and am not new to it on carb'd vehicles. But I don't need more than 450hp in my vette. 375-400 is fine especially if its a crossfire vette. The chevelle makes awsome power and gets crappy mileage but runs good ET's. I want more power out of the crossfire keeping it a "true" crossfire injected vette.

Ben's 84 vette is mid 12 ET car but has extensive mods done to it. I plan to do it differently,thats all really. Thanks for the help guys,I like the ideas and thoughts but Im gonna go centrifigal with the vette and stick to it. If i don't like it,i can always sell the D1 or P600B procharger unit to my buddy's.

 

Google "winaldl" and it's that guy's web site that has the SC crossfire on it.

 

Yup...
That's the one there dude...good call...

http://www.joby.se/

I know that this isn't a supercharged set up but its still one of my favorites from Turbo City:

http://www.turbocity.com/product_inf...roducts_id=541

That on a 383...would be too much fun...I smile every time I think of it....the TQ range would be flatter than flat....One day I hope Fast tackles this set up and puts it in his van.

 

Dual TBI would be fun, but I am doing OK with a single large bore TBI. I could always bump the fuel pressure some more on the current injectors or upgrade to 90s. The current manifold seems to extract the last bit of HP from every gram of airflow into the engine. It is after-all for a 2bbl race class.



I am running with a TranDapt TBI-Carb Adapter. I bought two versions and like the larger of the two better. They both work about the same though.

First One I bought


The 2nd and current one I am running

 

double

 

Fast...I know you don't really need a 2nd TBI...but what the heck? I mean...I am sure you could yank about 1000hp out of a dual TBI set up. If you getting almost 500 or so out of one TBI...why not try two...2 TBI's x 2 must equal 1000hp right? LOL.... ....LOL...hey I can dream can't I???!!!

 

500hp out of a single TB?! I didn't think that was possible without nitrous/turbo/SC? I didnt' would think there would be a point where 2 inj. hit 100% duty cycle and max out/lean out.

p.s. John....were you being sarcastic about 500hp? LOL?

 

LOL...at one time I seriously would've been joking but....if Fast's hands are on the engine...then no...no joke....

see this thread...
https://www.thirdgen.org/forums/tbi/...i-reality.html

JB

 

500hp is alot. I contaced holley to buy a commander 950system with 4bbl TBI 85lb injectors and they say it will only handle 550hp with a blower. Thats blown and not N/A which is much different. How much could a 2bbl 90lb injectors handle on a blown 144 supercharger 4-5psi boolst on 355cid? would 450hp be out of reach since 500hp N/A is happening? This question is concerning my chevelle not my TBI crossfire corvette. AM I Do i need to be...

 

Hi Shinobi!

I happened to look at the Procharger info this weekend. their bracket places their unit quite low on drivers side. seems should not be a fitment issue for your/my Vette unless you tend to want to keep a CF? likewise the air filter is placed directly behind the blower and attached to it. hopefully not too close to the #1 header
the bonnet comes in a low profile 2.5 inch above the top of carb or in my case 7.4L TBI. Ducting from blower to bonnet is polished aluminum. The Pro catalog is free and comes in about a week. I think running a Aeromotive VAFPR(supported by EBL) with high FP would work well. One could run low boost to start and work a base tune. and increase boost later as needed.

 

Hi Ron! I was gonna keep CFI going but was looking at how simple it is for us to just use L98 brackets and powersteering resevior,then use a L98 Procharger bracket which in my mind looks much easier since it would work. The belt routing and serptentine set-up of a L98 vette is close to a L83 crossfire and simple changes would be made at low cost. JoBy made a custom bracket which is way out of my leauge and did some relocating of alternator,brackets,etc.... Thats why I would just use a L98 mounting bracket and it would work the same for our L83's. Not too hard to do and bolt on,swap friendly.

If you follow me,its much easier to use the L98 stuff and a smaller alternator might have to be used but it isn't too much to ask for. With all that said and done,the ECM,TBI bonnet and fuels system are the draw backs. Making a bonnet for 2 1bbl TBI units isn't easy. Boost can be handled by a EBL equipped later model ECM and 2 Bar map. Sounds like a lot of work and it is. Might take me some time but it can be done.

on your car Ron, the lower 2.5" bonnet should work and I think it would be much easier on your TBI vette as mine. Your harest part would be fabbing up new piping to the TBI! LOL,not to much of a hassel actually.

 

Shinobi send a PM to V8Astrocaptain, hes running a 142 with a 350 TBI on his mid 80's caprice... a base estimation puts him @ 508hp flywheel not to mention that he got some friggen godlike MPH on the highway

 

Oh that sounds nice...do tell...do tell...

 

Here is my setup, I have plenty of power I am pretty sure I am over 500hp at the crank. 95 Yukon 4X4 6" RCD lift 305X75X16.5 BFG All Terrains.. Now here is where it gets interesting....383 Cu In. with Scat Forged Crank, 4340 H-Beam Forged Rods, Forged Dish Pistons, 8.5 to 1 Compression, Brodix IK180 Aluminum Heads, Full Roller Cam, Edelbrock Ceramic Coated Headers True Dual Exhaust, MSD Ignition W/Coil, Edelbrock Aluminum TBI Intake, Ported TBI Machined for Boosted Applications, 75lb Injectors, ATI Pro Charger D1SC With 2 Core Innercooler, Currently running small pulley and getting 11 to 12lbs of boost on 100 Octane Unleaded. Less than 2000 miles on motor and less than 150 miles on D1SC upgrade. I am currently running the FMU that came with the Pro Charger kit, this is where I get frustrated, I had Ed Wright Burn the chip and it seems to be ok, where I am having a problem is when I get to about 4300 RPM the fuel pressure starts jumping like crazy and I go into a very rich condition on my Wide Band Innovate logger. I think it is the stock tbi FPR, or the FMU is not working correctly. Do I have to run the stock FPR with the FMU or is there any upgrades to my computer that will allow me to tune my self and get rid of the FMU, I know I have more power to burn I am getting plenty of fuel the FMU has plenty more adjustment to give more fuel I just think the FMU system is a bandaid. I have spent lots of money on this system should I just upgrade the fuel system to a MPFI? Has anyone ever worked with the Edelbrock upgrade fuel system that works with our stock computer and uses the 8 injectors firing off the rail direct? Sorry for all of the questions you can see I need some help and any would sure be appreciated.

 

boa: I personally would work with what you already have. check out the EBL. Are you using a Aeromotive VAFPR? Many of us use EBL and it supports boost.