I've recently swapped my 5.0 TBI for a 5.7 TBI on my 1990 RS and was wondering if anybody out there has or knows anything bout this engine and its specs. I ordered it from Jasper Engines and the link is right here incase u all want to check it out....http://webapp.jasperengines.com/catalog/netcat7.asp

 

In 1984, the Corvette version was 205hp and 290 lbft.

 

yeah but this isnt a 1984 engine, so i'd think it'd be different. supposedly according to jaspers website, it is also a police (or was) engine, i think i might just email them and ask but im surprised nobody has this engine

 

From the "New to TBI" sticky:

Since Jasper stated that it was a "police" engine, then it's most likely an L05, so you've got about 205 HP (at the flywheel).

 

That sounds about right. My dads 96 GMC G30 van has a 5.7 TBI as well. Its rated at 205 hp.

One of these days I'll talk him into a cam and head swap.

 

The Corvette CrossFire motor represents the "zenith" of
TBI technology for GM. They really never took it any further.
Bruce is the person responsible for finally
"kicking it up a notch".

 

TBI isn't responsible for the 205 hp rating, if thats what you mean. The blame lies with the cam and heads.

 

92blue,

Yes, you are correct. In fact, that's been my little project for the last 4 years. Demonstrating that a properly modified Xfire intake can support quite a bit more power than the advertised 205hp.
The 84 actually is transformed when you have a motor developing 350+ hp using the great 84 Z51 suspension coupled with C5 brakes, ZR-1 wheels, ZF-6 trans and a D44(3.42's)

 

Love the vette, I have a 350 TBI. I put on TPI heads to get rid of those crappy swirl ports and I put on a ZZ4 intake. When I get back from Iraq a 750CFM 2" TBI will be going on which would be good for up to 400 HP. Also a new fuel pump and a chip burn. A cam might go in as well but from what I hear I might have to put on differant heads...again to get the best gain. So...Vortech heads and a matching cam in a year will most likely go on. I would imagine this would be good for closer to 320 and up HP. Eventually converting the auto to a dodge viper 6 speed manual and the rear end to disk brakes along with upgrading the suspention and front brakes. That whole set up will cost me 7-8 grand if I am lucky.

 

Dom',
let us know how your project turns out.

Will you be keeping the cfi manifold?, if not,
I am interested in hood clearance issues
as I am contemplating switching from CFI to
TBI / different manifold, or carb.

 

Red,

When are you getting back from Iraq. Keep in touch. Feel free to email me direct on any questions you may have. My email is surrexi2@comcast.net. BTW, since you live in PA, one of the "PhD's of TBI" is nearby, Mr. RBob.

Contact,

I am using the Xfire manifold with bored TBI's, with lid and injector pod spacers. The manifold's been port matched to TFS heads and Extrude Hone'd. For more info and pics go here:
http://www.crossfire.homeip.net/cfte...ID=18&CAT_ID=1
I have some interference with some paint rubbed off the magnesium air cleaner housing and the hood, but nothing terrible. Hood slams shut. Much of the mods have been well documented by Bruce and others on this forum. Not sure if anyone else has ever taken the step of EH'ing the manifold however. CFI has always been a torque motor and this one continues that only at higher rpms. You'll find the problem with CFI wasn't necessarily the manifold. More importantly were the heads, cam and crappy fuel distribution due to the TBI's being in series and using 2 different size injectors.

 

Dominic Sorresso, I am not in PA...that is just where I am from. I am stationed at Ft. Bragg, NC. But I will keep in touch through the boards when I can if the site is not restricted when I get to Iraq. I will email you for help if I need some when I get back also. I am trying for 350-400 HP at the rear wheels while still using TBI. I just want to show people up and that it can be done. I would like to see even more than that but we will see. I would like to just throw this out there to see if some one could answear this for me. Can a super charger be used with a TBI? How about a twin turbo? If nothing else I will start my own thread with these questions as not to take away from this one. THX

 

Been done. http://www.crossfire.homeip.net/cfte...=display&id=27

 

Kwool.

 

Somebody give me $3000 and I'll make 450rwhp with TBI. It won't fit under a vette hood but then again how could I show off that it's still TBI if you couldn't see it .
I still haven't seen a limitation to the TBI form of EFI, only the limitation of knowledge. Now that I've seen (and experienced) the code limitation it's a no brainer that TBI got a bad wrap.
Those cross-fire engines do so many things right yet so many things wrong, lol. Where to begin .

 

Jon,

The Vette has little 'CROSSFIRE INJECTION" stenciled on the front fender insert. Going stealth is soooo much fun. Like putting a 307 engine insignia on a BB 70 Nova.

 

Here is the major problem.
.

 

Sorry, know you ain't talking about me, but it sounds cool anyways

Bruce (90RS305)

 

Bruce,

No, I am speaking about "THE BRUCE", Grumpy.

ComtactPatch,

Yes that shows part of the problem with the CFI intake. The Manifold/Cylinder head interface is a mismatch. The manifold has a port 2/3 the size of the head port. But Grumpy was able to run mid-13's even leaving that alone. Removing the EGR channel increases plenum volume while parallel plumbing the TBI's allows for use of larger injectors and balances the fuel distribution MUCH better. The motor really is quiet when this is done suggesting that the cylinders are now firing evenly and equally. If you have ever pulled the plugs on a Xfire, you'll see how bad the fuel distribution is on a stock motor.

 

anybody here own or know anybody whos dropped one of these Jasper 5.7 TBI's in?

 

I have a 1990 Blazer and the TBI 350 is rated at 210 HP and 300 TQ.

There is also a cam in it now though.

 

Who cares what a jasper 350 makes. That doesnt mean anything. What are the heads, the pistons the cam, the intake. Do you have any actual specs on the engine besides "police"?

I built my engine, so does that make it a Simmons 350?

Give some numbers up and people can estimate.

Its probably a stock rebuild using crap parts and swirl ports anyway. Add way more cam, port and mill the heads and swap a better intake and it would be a vast improvment.

 

double post

 

I really miss my crossfire car now.

 

I can't vouch for the Jasper one, but I got my 350 from http://www.goautocenter.com , but I went for the 350 TPI.

It's got some ***** now, but computer tuning is a bitch. I really, really dislike computer tuning. I keep just wanting to reach underneath and re-jet the thing.

 

Hello all from Kuwait! I leave for Iraq soon and just wanted to drop a line to all. I cant wait to complete my camaro when I get back. I should have about 8 Grand to play with for a good paint job and body work. Should look like a million bucks when I am done. I also will do my chip work when I get back so I might get a dyno done to see how I have improved. Thanks for everyones support too!

 

red johnny,
*** speed.

You mean you edit *od Speed on this forum???!!!

 

Yeah, G0D is a bad word , didn't you know that? lol, when they first started removing words I was suprised about this word as well. They might as well make every name *****! Hi, my name is ***. Or Yo ****, you need too...

 

Strangely enough, so is red-neck, see> *******

 

I can actually tell you what thread percipitated that, if it wasn't deleted.

 

Jon,

You know I'm no Biblethumper. But I'm just trying to wish red-johnny good luck and come back in one piece.

 

I thank you all for the concern. I do not believe that go* is edited either. It seems that even though our country was founded by g*d believing people and also our laws down to swearing on the bible that people get offended by such a small word as this! Maybe just maybe they need to found their own country for I fight for the freedom to say words like *od and church. I thought that was my born right as a united states citizen....but again we let the views of the few take control over the views of the many. Sorry to preach but I am in the army for my country and the rights we are allowed under *od. My heart and sole go into my cause and if your son, daughter, friend or what not is ever under my command you can guarentee their safety is protected under the fullest extent of my ablitity. Any way now that I got this thread so off topic, lets try to get back on.

I am going to be putting on a new TBI thats good up to 750CFM and has potential to 450 HP. It has 2" bores and that should open up some potential for my camaro. I also want to put headers on it that way I will then have a full new exhuast system. Any other ideas besides a chip burn that might spice up my proformance?

 

RedJohnny,

I think you'll need something bigger than a 2" BORE. I'm using 2.13" bores on my Xfire which flows about the 750cfm you're looking for.

 

In need of a little assistance....

I just got an '85 'Bird with a rebuilt 350 TBI... He was a college student and was working on it/buying pieces for it from the dealership he was working at. Spent over $1,200 on the engine rebuild.. I have most of the receipts.. he bored it .60 over etc..

anyway.. the question is, for some reason he installed a manual choke. Why would he have done this.. and how can I swap it back to an electric one? Thanks.

 

Maybe I'm not understanding your question right, but TBI's don't have chokes.

 

LOL.. you're right... brain fart last night... air cleaner was throwing me off.... it is a carbed engine... and installed a manual choke. Runs really rough for the first couple of miles till it warms up... kinda annoying having to screw with it. Any suggestions? Thanks for the clarifier.

 

Might wanna check out the carb. board for that...

 

Actually I mailed Jasper a while back and they replied that Its rated at about 250 hp and i think 330 tq. Not too shabby w/ 40 series flows, open k and n, shift kit, and more. I just really need to get a 3.73 posi and some headers and a chip

 

The choke is in the code. Learn to burn.

 

Old thread brought back, but a good read definitely.

Dominic, that's the first time I've seen your car actually, kinda surprising to me that I haven't seen it before. Great looking 'vette though man! Where is Bartlett? You should go onto the NW Indiana South Chicago regional board, there's a map signup where u post ur handle and where u live and it shows everyone on the map there, check it out

Nothing really technical to add to this thread though ha.

 

Bron,

Bartlett is in the NW suburbs of Chicago. I am west of O'hare and Woodfield Mall.

BTW, ran a 13.3 @102mph 2 weekends ago at Byron Used street tires at 35psi.

 

Cool Dominic, I'm no more than 45 mins away from you then. Check out the regional board definltely, there are a lot of guys from that area. I'd like to meet up some time maybe next summer or something at a track maybe. Good to see some TBI guys in my area, it seems hard to come by.

Jim

 

I have a jasper 350, bored .40 over in my 91 RS. We were under the impression that we were installing the L98 block and heads, however we discovered that we were actually receiving a L05. Bummer, i know. Anyway, after just about every bolt on, im still looking for something mroe from this boat anchor motor. I was wondering if you guys have any info on the performance gains if i installed an Edelbrock intake manifold, coupled with the bigger throttle body and injectors we already have? I looking for a significant gain in the top-end of my power band, cause the car seems to hit a brick wall at aounr 55mph. Dont get me wrong though, it's got some grunt down low, but the car still runs a measly 9.7 in the 1/8th. PLEASE HELP!

 

There are a lot of other prooblems to fix beyond the manifold. Upping the injector size, and TB won't get you anywhere either, unless you do computer work.

I'll say this again (I sound like a broken record), computer works is needed WHENEVER you modify these motors. Heck, its needed for a stock motor.

BTW 91BadRS, I already replied in the thread in the aftermarket parts board, about intake manifolds.

 

Thank you, and sorry Dewey, just my older brother (*** of everything GM in case you didnt know) jumps all over me for not posting in the right forums, for not asking the right questions. Im just trying to learn as I go along, haha. Thanks again

 

So true. You need the right tools as well. I would get a WB O2 to see what is happening at the big end. Getting the right AFR/timing there is mucho importante.

 

i have 1989 Irocz 305tbi 5 spd everyone keeps on sayin need to tune the computer ,Does anyone have any good programs they can share id like to give it try on my maro
Help a brother out

 

slowpoke89

Start with the stickies in the DIY-PROM board. Get ready to do a lot of reading.

 

Dom.........was this run with the following?

350ci

cam with 218@.050

528"lift with 1.6 rockers 108 LCA

Trickflow heads.

Is this your combo as I have it down as that.?

DM

 

Yeah, that's the combo. Using a modded Xfire manifold, //plumbed TB's, #80lb injectors @ 20psi, 7747 ECM, TPIS headers. The cam is a CompCams Hyd-Rlr so the effective duration is higher than a flat tappet with similar specs. The Trick Flows are the 23d variety.
And here's the results!
http://jeff.vettextc.net/byron_10-22/pages/100_2819.htm