Alex IROC Z-28

Hi there....I am having a vacation of my house renovation so I can dedicate to my IROC.......

I am a bit frustraed with the numbers that my "new" engine gave me.
My car originally was 305TPI, and I swaped a L98 from a 1987 Corvette(aluminum heads)...plus 700R4 and 3.23 rear end.

I have edelbrock short heads, hi flow magnaflow cat, 3 inches pipe dynamax, mufler super 80.

My "new" engine is running with the 305 ecm plus the hypertech chip.

My numbers 202RWHP 302 RWTQ. I just use sunoco 94 on the car.
I also noticed my car was pinging a bit on the dyno....but I am far away from what I want to have on my RWHP/RWTQ....

I though a 300mark rwhp is enough to have fun and to have a reliable car the summer....well gas is cheaper but let's leave that still on mind for the FUTURE lol....lol....lol

I going to get my vacation pay soon so I want to buy some parts for my car.

I thought about new runners (but I didn't diced each brand/model)
The intake it's not a bad idea, but that gonna depend of my runners......right?
What about my heads should I replace it? or they are good enough for the 300 range?
I problably need a new cam..... what options I have?

I don't need something that gonna rip asphalt from the streets but 202RWHP IS A BIT TOOOO BAD FOR A CAMARO lol.......

Tks for all.

Russ-So Cal

You need to read the sticky titled "Performance Proms, also TPS enhancer snake oil, and otherchip basics." Your hypertech chip is a stock factory chip or close to it. You paid bucks for something that is not what was claimed for it. I know it can take a lot of time to read all of the info in this site, but if time isn't cheaper than money, expect to get taken.

IROCThe5.7L

Did you re use your 305 knock sensor?

Russ-So Cal

Good point, I forgot that the 305 knock sensor won't work on a 350.

Alex IROC Z-28

I took the engine off the vette and put it strait on the camaro... all the sensors pretty much are the ones that were on the vette....

Why the question about the know sensor? because of the pinging???
----------
I bought that hypertech ship over 5 years ago.....the thing that I liked was the dropping of temp of the engine...or better, the fan started at 160 insted of 180/200 degrees....

I saw many options, I see people with "crazy" ideas.... one of the things that I am trying to get away of is SWAP TO A LT....LS!!! I want to keep my TPI, but I want a bit more power......according to the prospects of my engine is 240 HP + the mods that I alredy have I was thinking to get the 240 ..... and I AM at 202 lol..........SUCKSSS................

Russ-So Cal

One other thing I've just thought of. What sort of exhaust system are you using? One of Dyno Don's buddies had a G body El Camino built a few years ago with a 383. It had a set of Edelbrock headers and "Y" pipe with a Holley 4 barrel. It didn't seem to pick up any power, so he had it tested on the dyno and it showed a max of 250 rwhp. He brought it to Don to find out what was wrong and the first thing Don noticed when he put it on his lift was that the so called "Y" pipe was actually a "T" pipe, and the "t" was the same diameter out as the 2 pipes in. Don fabricated a true Y pipe with 2 inch diameter pipes in (IIRC) and a 3 inch out. When the El Camino went back to the dyno, that one change picked up 75 rwhp.

Hawk92z-TDZ

That hypertech is for the stock 305, even the stock 87 corvette chip would work better, fact is he needs tuning, ping'n on the dyno and did you ever chk what your timing is set at, my first guess would be its lean too, Alex as I and everyone else told you on our board already, get what u got tuned and figured out before adding more mods to it and compounding problems

sgt473

I read that the EST control all so has to be changed when replacing a 305 with a 350.

305sbc

iTrader: (3)

Were the accessory pullies and all the same? or did you swap one type for another type?

Some people accidentally spin the reverse flow water pumps the wrong direction after a swap and have problems.

Have you checked your fuel pressure and/or done a sparkplug reading?

badblackiroc

are u using the original 305 injectors, or did u use the the ones from the vette? and if u did use the ones from the vette and the prom is only tuned for the 305 injectors it will cause it to run lean. and do you have a adjustable fuel regulator? its easy to tune the pressure because the 350 injectors need more pressure, i think if my memory serves me right the 350 injectors need 47-50 lbs of pressure. and i would strongly recomend howell-efi to reburn ur chip.
howell-efi.com the number is (810) 765-5100 talk to Troy Brown. he burned my chip for my 88 iroc and i wouldent trust anybody but him with my chip.
he had my chip back to me in a week. im running a crate gm performance 350
with lt1 injectors no smog, no egr, and im running 320 hp and 385 FT Lbs.
troy helped me out and just tell him Joseph Falco refered you.
i think he charged me 200-250 for my chip. any other info u need just ask.

Alex IROC Z-28

I think before I didn't exectly explain what I want to know.....

My engine came complete from the Corvette. The only thing that I used from my 305 TPI was the ECM.

I know I have to tune the car. The numbers will go better for sure after I do that, but I know won't go to where I want to go........

What I was wondering is.....

What kind of cam, runners, intake, heads, u guys USE or SUGEST.....??? what results u guys have?

What I was trying to find out is from the guys that have 350TPI what they use, what results u guys have?

TKS very much.....

Mike-91 Formula 350

I think 300 is asking a lot from a stock motor swap.Those Vette engines dynoed 325hp at the flywheel back when new with dyno headers.Remember LT-1's hit 240 or so at the wheels stock.RW dyno tune can be your friend

Alex IROC Z-28

I am not looking for a number....well I would like to have 300 hp or more for sure.....

but I want to improve more and more....

305sbc

iTrader: (3)

If it was me I'd try to resolve the problems causing the low power first before starting another combination of parts.
My first recommendation is to start learning to get into DIY PROMs/tuning. It is more work than simply swapping some parts, but it will be well worth it down the road and it will bring you closer to your car through understanding of how it is working.
It could easily be your best performance modification.

As far as power part combinations you'll hear something different from each person.

I am partial to LPE hydraulic roller camshafts. Heads I like are L98 (what you should have now), LT1/LT4/Vortec, Canfield, and TFS - all with porting and performance valve-jobs. For exhaust I like SLP 1.75" shorties, 1.75" Longtubes, and Borla CAT-back systems. For automatic cars I like intakes with the longer runners like the TPI has, or HSR intake.

If you master the tuning part of it a combination of parts similar to what I have listed will get you the power you want and maybe more.

Alex IROC Z-28

Thank you very much....

Russ-So Cal

You don't mention where you got the 240hp number from. If that is advertised flywheel horse power, you are over that already. Your 202 is rwhp isn't it (from a chassis dyno)? On a stick shift car expect a 15% drop in power due to power losses from the flywheel through the rear axle. On an automatic, expect a 25% drop in power between the flywheel and the rear wheels.

Alex IROC Z-28

That's a good question I read in some webpages over the time that I purcharge the engine 1987 vette .....the guys mentioned to me about the loss in my 700R4 be 25%...
I know after I straight the car out I gonna get it more from my actual "package".
I wonder how much more I can actually get? and what is going on with the other guys/girls, that drive 350 TPI, what "package" they are using? what results they have, etc.....
I don't mind to hear ideas from everybody.....
Let's say that I am a bit ignorant of what is out there..... I can read many many posts, webpages, etc.... but the final word is the driver/onwer of the car.....

Russ-So Cal

I didn't notice until now that you said that you used the ecm out of the 305 with the 350 out of the Vette. I don't know what the Hypertech chip wass burned for. The stock injectors on the 305 will be 19# while the stock injectors for a 350 are 22#. The ecm can handle either one IF the chip knows which injectors you have in the engine. If the chip is set up for a 305 and hasn't been reburned, it thinks you have 19# injectors in the engine, and sets the duty cycle accordingly.

neat

I'm not sure I'm interpreting this correctly, but it sounds like you are running the 305 computer tune on the 350. If that is the case, that could be the reason for your low power numbers.

My 1991 Corvette ended up making 275 RWHP with all the stock stuff in place using this combo of parts:

Cold air induction
1.6 full roller rockers
Hooker 2151 headers with no cats
Dr. Gas 'X' pipe
Magnaflow mufflers
!frisbee
Breathless performance AIR pump eliminator
Dyno tune

The biggest thing I did was the tune. When I strapped the car down it was making 230 RWHP. I ended up making 44 pulls on the dyno tweaking the fueling and timing. I ended up with 261 RWHP after that session. I then added the roller rockers and made another 10 pulls or so and was able to hit 275 RWHP.

The difference was pretty amazing based on the feel of the car.

Alex IROC Z-28

Thank you very much, that's exectly what I was looking for.....

Your car still TPI or is LT1 alredy?
You took off the the air pump?

neat

My car is/was an L98. I have a converted LT1 intake on it now, along with some trickflow heads and a comp cam.

In the configuration above (stock L98 pretty much) the car ran 12.80's at 106 and 11.90's at 112 on a 75 shot. It probably would have went faster but I have 4.10 gears in the car, and with the little lungs of the stock TPI I was shifting into 5th gear at about the 800 foot mark at the drag strip.

Alex IROC Z-28

Your lt1 intake made a good change on the behavior of the car or not much?
The entire top part of the engine is LT or just the runner, plenum, intake?

Damon

Agreed with above comments about the 305 tune on the 350 engine/injectors.

Aside from overall differences in tune (of a bigger engine with substantially different breathing characteristics), one thing that a MAF-equipped car just can't handle is injectors that don't flow what the ECM is told told they flow (in the chip programming). ECM programming thinks they are 19# (stock for 305 TPI), when they are actually 22# (stock for 350 TPI).

If you want something quick and easy, try getting hold of a chip for an '87 L98 F-body and pop it in your ECM. It'll probably run better than what you got now. The Vette L98 and the F-body L98 were not all that different aside from the aluminum heads. Beyond that, you're into custom tuning.

Hawk92z-TDZ

I already offered to do that for him last year

He laso told me he wants to use the stock heads, thats fine as they will give the power level he told me he wants, he also said he wants it to look stock, well thats the TPIS/AS&M Runners, Edelbrock makes all the LTR intakes so all thats left motor wise really is cam selection, then stall and gears too match

If you dont care about looking stock, the sky is the limit for what you can choose to do.

Get what u got fixed first then worry about the rest.

If you dont mind Semi-Stock looking ,then the FIRST set-up is nice

neat

The LT1 intake is almost identical to the miniram intake. They are both one piece intakes, so they don't have a separate plenum, runner, base, etc...

The only LT1 part on my car is the intake.

The car is much faster with the LT1 intake VS a TPI system. I shift at 6300 or so now, where before I was shifting at 4800-5000.

You have several problems with your car, and unfortunately your ability to communicate using the forum isn't the best. It is difficult to understand exactly what you are experiencing, so it is difficult to provide assistance. I'm not sure if English is your second language, if writing coherently is just difficult for you, maybe typing is time consuming and difficult for you, or it's possible you just don't care enough to clearly express your problems using the written word. Please don't take offense, I'm not trying to be mean, just letting you know that what is crystal clear to you isn't clear to the rest of us.

In any event, all of us here are trying to help, so these are the questions I/most of us have. If you can answer these questions clearly we should be able to get you going in the right direction:

Which ECM are you using? Did you take the ECM from the vette, or are you using the ECM from the 305? What chip is installed in the ECM? It sounds like you are using a hypertech chip designed to run a 305, but I don't think any of us are 100% on what chip and ECM you are using.

You mention in your first post that you have Edelbrock shorty heads. Do you mean headers, or does the engine have Edelbrock heads on it?

You don't seem to be interested in resolving the problems you have now. Instead, you seem like you want to modify the engine to make more power. That doesn't make sense to most of us. The parts that you have now are capable of another 50-60 RWHP if they are working properly. Do you have a plan to correct the problems you have now, are you hoping the problems will go away with addition of new parts, or do you have some other ideas? What is your plan/goal with this thread?

Good luck with your car, I hope you get it worked out.

Alex IROC Z-28

Well first of all, thank you and all the members here. English it's not my first language, is my 3rd. lol .....or almost the 3rd.

Well let's see if I can explain in my best possible way.....

On may car I use the 305TPI ECM, my engine is a L98 from a 1987 corvette. I know the problens of my car, and I will fix them on the summer. But I still think my engine it's a bit low on power. no my in particular but the stock L98 in general. So I would like to know from you guys.

What improvements you guys have on the L98 in general?

What options are around?

I know I am a bit far away from my topic, but I got curious about what is around here....

Once again thank you very much for all the help.

Alex IROC Z-28

Well I am not asking much from my car....lol.... 1/4 mile in 8.2 seconds, 0-60 2.1 seconds and if is not asking too much 45 miles per gallon......

Just joking a bit..... I want a fun car to drive, that I can go to the 1/4 mile with my friends, travel, auto cross, and take my grand mother to the park.....lol lol lol....

I don't need nothing to crazy.....I though 250 and up.....torke in interesting also to go up, but the punch that I have on the car is alredy enough to start to have fun......

I want very bad to go for a T56 in the future, but the economy it's to instable right now so I am putting this plan for the future....so I gonna keep my 700R4....

I am thinking about a bigger cam, better heads, better runners. But if I can make my actual setup get what I want I will leave the way that it is.....


One day in the veryyyy far future I am thinking about 300up on the wells, but I am not on the hurry for that much.....