i have a chance to get a 1992 rs wit a tbi 350 swaped and tuned or get a 1986 iroc i with a 305 tpi they are bvoth about the same price same miles and the iroc has a nicer interior which would be better for my gole of beating my friends 1999 mustnag gt and keeping up wit my other friends 2003 WS6

 

You have some ambitious goals there with the 2003 WS6....

If you get the IROC - you will have to swap the motor to a 350 (nothing is wrong with going bigger than that either ), and with the RS, you will probably need to get out from under TBI. Do you know what the 350 in the RS has on it? If it's a stock LO5, skip it and go for the IROC, since you'd have to do a head swap anyway - which is just shy of a motor swap.

Just depends on how far you really want to go with the cars. IROC - Motor Swap. RS - Injection and head/cam swap at minimum. That's assuming both cars will need gears, TC's, suspension/chasis work, etc. If one already has some of those mods, go with that car I'd say.

 

Go with the '92, especially if the prices are roughly the same. It has a stronger tranny than the '86, and has the aero gfx, which will hold for higher value. It also has 28 spline axels, which mean they are slightly stronger and you can use a 4th gen differential as opposed to the iroc's 26spline.
A half way descent 350 tbi will have no problems smoking a GT, but if it is the crappy L05, there is still hope. That block is a 1 piece seal and set up for a hyd roller cam. Swap the cam, heads and intake and you have plenty of potential.

IIRC, the '86 305 tpi's only had 190hp, you would end up needing to do the same things to that as you would the L05, but without the benefits of a hyd roller cam, and a lot more $$$ on the tpi parts, and still have a 305.

I say go for the '92 RS.

Oh, and uh, good luck beating the '03 WS6.....In fact I've never heard of one losing a single race

 

Oh yeah, keep in mind the RS never came with any kind of 350 stock, so it is definetely worth looking into. Try to find out if the 350 was pulled from another vehicle, i.e. caprice, C1500, or if it was built. Try to make sure it is a 350 also....I remember when I was looking for another project, a guy had bored his 305 .030 over and thought that made it a 350.....

 

CoughCough*TPI*CoughCough

AhhhhCooo*TBI*Sniffle

 

*cough* I own a '91 z and a '91 RS

But let's see, my Z-28 has a 58mm TB ($300), a TPIS Big mouth intake ($400+), TPIS runners ($200), VAFPR ($?), and 32pph racetronix injectors ($260) and a poorly tuned ED Wright chip.

Luckily, I bought the Z with that stuff on it, obviously there are other routes to go to get the thing to flow, but whatever way you go it's well over $1100 just to make the tuned port flow. That doesn't even take into account that the '86 is MAF....

Considering he said he wants to keep up with the ws6, your talking 13.2 in the quarter. A carb intake ($110), adapter plate ($40), and a Holley TBI ($290) can do a 13.2 all day long.....

I would think money is a factor, so why spend more on a car that generally goes for less ('86)?
Go with the '92, check the tbi board, and will get the information you need, and will keep up with the ws6 for a lot less then if you went with an older 305TPI.

 

I'm going to preface what I was originally going to post by saying there are some quick TBI vehicles out there. There are some TBI vehicles that run great, and run for 100,000+ miles. There are some "Fairly" cheap mods out there for them... But for TBI to take on MPFI in a heads to heads match? The ECM alone is not up to the task, with it's slow rate, and limited abilities - which is the heart of the whole idea behind EFI. Now, since the cry baby above would like to venture down the road of assured arguement, let's stroll, shall we?

Apartently you think you are the only person with both a TBI and TPI vehicle I own a 305 TPI and an lo5 vehicle. The LB9 SMOKES the lo5, every day of the week. In fact, I just bought it recently - you can check the classifieds to verify that, as well as your TBI board to verify my posts about my lo5.

I'll make this quick - an lo5 with those mods first, won't run worth ****, and second ..... won't run anything NEAR a 13.2, or 14.2 for that matter. I'm sure that monster LO5 cam and high flowing swirl port heads are up to the task

His LB9 heads have been shown to flow about as well as vortec's with DIY port work. The $600 - $1000 he'll save in new heads, he can rebuild a junkyard 350 from scratch, run the TPI heads with the benefit of small chambers, and slap a converted LT1 intake on top of. Both engines will need cams, so that breaks even. Actually, it's still probably in favor of the TPI, because you don't need a more expensive roller cam to run 13.2's - but I'll give you the benefit of the doubt.

The diference? He'll spend about 1/4 the time prom tuning a MPFI setup as opposed to a TBI setup, and have driveability that a similar TBI setup could only dream of. While we are talking about tuning - let's just say that the RS 350 has high flowing heads and a not so mild cam.... who did the prom work, because that sure as hell isn't running on stock programming! Who do you trust to be sure they datalogged properly and aren't sending that engine lean? Best question yet - HOW DO YOU EVEN KNOW FOR SURE IT IS A 350?!?!

At least he knows what cards are in his hand with the Iroc

Oh and just to really **** you off:
($110), adapter plate ($40), and a Holley TBI ($290) = $440
LT1 intake = $400

 

it is a hard chpoice i know for sure that the rs is a 350 and it is getting tuned right now but i am leaning towards the iroc and with the rest of the money i have getting sum vortec heads milling them for the 58cc chamber i would need and getting the new edelbrock intake they jsut cma out with for vortec heads on a tpi car and working from there

 

Go with whatever you feel will meet your goal. Just keep in mind the rs is a 25 yr ann., and check autotrader and get ideas of what irocs go for as compared to any '91-'92 model. Best of luck on your choice and the project.

Goy, I figured it was pretty much implied.....but since you obviously think I am stupid, I will go through this all.... If you are going to reach a goal of 13.2 with either the LB9 or the L05, not only will you need the mods I previously mentioned, you will need heads, cam, exhaust, fuel pump, and computer work for both applications. But since those are relative to both apps, the only price difference will be in the induction..
Sounds like you don't know what your doing and you shouldn't use your poor experiance as grounds for example.....considering my L03 (thats right L03 not L05) car runs a better quarter then my friends '86 iroc lb9..... and he had headers, shift kit, and a posi 3.42 rear end. My '91, with nothing more than an underdrive pulley, tbi mods, advanced timing, various deletes, msd, cutoff exhaust, and a few suspension mods runs 15.1-15.2s at 91-91.5mph. That is with 2.73 peg leg and stock manifolds. My friends iroc is lucky if he hits 15.3s
I am not saying that the lb9 is a bad engine at all, but you cannot say that it will smoke L0x's because that is just not the case, and you can check the tbi boards and see multiple 305s running those times with those mods.

However, 2bbl tbi is much trickier to make work with mad power (though 13.2s are very achievable), were as tpi has been there done that. Thus, that is what my Z-28 is for That and the 150 shot which better take me deep into the 11's

 

I wanna see some pics of this 03 WS6...

 

I can see both sides of the arguement here, but i would still go with the IROC for a few reasons.

TPI will get better mileage than the TBI and with the MAF sensor you can mod it a fair amount and not need a new chip burnt. I know this because i just took my car to the dyno and it was only about a half point rich and could have just a tad more timing added. but other than that my car runs fine with teh stock chip. The guy at the dyno said there is probably not much more than a few horsepower left in the car because the stock chip just does not hurt the car any. now speed density TPI or TBI is a whole different game. they do not put up well with modifications because the computer calculates their fuel requirements whereas the MAF setup measures air coming in and adds fuel accordingly. This reason alone i feel is a huge reason to go with the TPI car.

The biggest reason i woudl go with teh IROC is becasue it seems like the most unmolested of the pair. with the RS you are buying some one else's project which is rarely a good idea. Unless this guy is one of your best buddies and you have seen all the mods done to the car, dont buy some one else's hack job. Buy the car that is unmolested and has the better fuel injection system, you wont regret it.

by the way check my sig, I have not ran with my new 5 speed tranny yet but i would imagine i am getting close to your buddy with the WS6, probably within .5 seconds or so. There are many many TPI 305s on here that run hard, do a search for the following members.

TimBurgess
TunedPort335
mw66nova
sittingbull
Willie

Hope this helps you decide.

 

Good points 1meanZ. I guess it really comes down to how much money ya can throw at the project, and from the sounds of it, the iroc is a little less than the RS, so overall they would be about the same cost wise by the time the project is done. And it would be completely his project with the iroc assuming it is pretty close to stock.

Those are good numbers also 1meanZ. Have you had any problems with the wrapped edelbrock headers? I am running uncoated edelbrocks on my Z and would really like to wrap them (mainly do to the 6 and 8 plug wires) but have heard that can cause them to crack.

 

Thanks, I am hoping to run better with my new 5speed. The car is so much cooler now with a stick shift. GM should have made alot more of these cars than they did. If they would have made more 5 speed cars back then, and if they would have coupled the 5 speed with the TPI 350, I dont think 5.0 mustangs would be enjoying the success that they are today, I think 3rd gens would be.

The header wrap is pretty cool, it keeps underhood temps down and keeps me from melting plug wires and other wiring. I have also heard that this will cause headers to crack. This is because you are "mummifying" the tubes. they can only shed heat on one side and this apparently weakens them. I only planned to have these headers for a few more years and i only put about 8000 miles on the car per year, so I doubt they will be hurt by the time i am done with them. Regardless of the wives tales of cracked header tubes, I have no issues as of yet anyway.

 

My LB9 ran 15.10 dead stock with a horrible rich condition. With a CAI,headers and an AFPR it ran 14.63 still running pig rich. I also would bet money that I have less invested in the price of my car and the mods than you.

 

biff85ta- calm down, don't be so insecure, and most importantly comprehend what is stated first before you reply.....

What did I say in my posts? Lets see..... Goy posted that the lb9 will smoke check an L05 (350). My reply: My L03(305) is faster then my friends '86 Iroc. I run a 15.1. That is not fast, but I would not say your 14.5 is "smoking" compared to my times...especially considering you have headers and an AFPR and I do not.
Further more, your car may have ran 15.1 stock *pat on the back 4 u*, but that's not to say the '86 boredemkills is looking at will run the same. It could run better, or it could run worse.

Yeah, you probably have spent less on your car than I have, good for u. The rs is the second 3rd gen I bought, and I knew from my last project what I wanted and what i didn't, and my overall goals. Check my sig. I can bet that I have spent less on my Z-28 then you have, and promise I would eat u up giving you 10 cars. Big deal though. The sad part is that you don't even get that my RS has nothing to do with the cost comparison.

Reread my earlier posts and you will see my point. Niether of the cars boredemkills is looking at will hit 13.2s with out extensive modding to include cam heads headers etc. That is obvious and assumed. So the only differences would be the RS has a 350 tbi and the IROC has a 305tpi. Simple fact is the 350 is more capable of making power than the 305. That is fact. Further more, the rs's 350 probably isn't an L05, seeing as the computer needs to be tuned as opposed to simply swapping in the L05 chip. So that simply leaves induction. Both systems can hit those numbers, but tbi will cost you $300 for the Holley unit and $110 for the intake. Now do the math on what a TPI will cost him to reach those numbers and garranteed it will cost more.

Like I said before, which ever car he desides to go with, I am happy for him, and am always glad to see someone modding their 3rd gens. And if he goes with the TPI, there is much more potential to go 12s or 11s, not to mention a larger community to help/advise him. But case in point, he said both cars are about the same price and he is looking to keep up with his friend's WS6. From a cost perspective the '91 RS is a better choice to reach those goals.