ok, so i had a 305 tpi last year, had it dyno'ed and it had about 230 bhp. since then ive had a 350 put in (tpi), with edlebrock heads, crane cams cam, 1.6 rolloer rockers. with 100 shot of gas i ran a 12.9 so im guessing that without the sniff id run a 13.9 right? maybe?? any way ive just got back from the dyno today and the guy there said i was making 260 bhp and 340 lb/trq. is he serious or what?!! he said that he usually tests BMWs and that he doesnt do many american cars (im in the uk). please answer!!

 

Has it been tuned since you did all that work? Which crane cam?

 

no, i dont think it has been tuned. it still has the stock 305 ecu and 305 hypertech prom!! it ran a 12.9 though with gas so it must have more than 260?? it certainly feels like it has.

 

anybody else have any ideas?

 

Do you still have the stock tpi on top still if so i think that is really holding you back at this point,you should though be making at least 280-300 hp[depending on the cam] at the motor and alot of torque.I think if you upgrade the intake you will be very surprised

 

yeah, still all stock tpi stuff. i do have a 52 mm T/B that ill put on at the weekend. all the other stuff will have to wait till i have the funds. it just feels like ive gained soooo much more than 30 bhp over the old 305!! even without the gas i guess id run a 13.9??? i ran a 14.8 with the old engine. surely i MUST have an extra 100 bhp???

 

What MPH did you run? Use that to calculate your rwhp.....its pretty accurate.

 

I dont think that you have gain that much its a tune port not a ls1 if you got a hsr or mini ram you might have an extra 100 combined with everything else but for now your stuck,most people dont realize that gm did not plan to use a 350 in the camaro or birds so they designed the tpi system to make good low end and midrange on the 305 and it did but do to strong demand they brought back the 350 but didnt upgrade the base or runners which is why there wasnt alot of power difference in them from that factory.The 305 made almost as much power when it first came out as it did when they stoped making them because they lost power in the middle years so that the 350 would sell better

 

true. i guess im just a bit disapointed, i spend a shed load of money for what seems like not a lot of return!! mind you with the gas i have done a 12.9!! happy with that. next on the list is intake and runners then. i was going to get them next anyway, will just have to be patiant huh?!! thanks for the advice

 

Dont forget to have the plenum ported also.

 

the TPI chokes the crap out of the motor.

it doesnt matter what long runner TPIish mods you go with, they all suck..


swap to a diffrent intake setup, and see a nice gain.

also, tune the thing... did you atleast have a wideband on it when it was on the dyno? is it getting enough fuel?

 

LOL.... I love my TPI. Just cuz you dont. Nothing beats the look of a nice TPI set up in a car.
And I tell you what, I gained alot with my Edelbrock hi flow intake, Edelbrock hi flow runners and a ported plenum. You get a TPI to flow good. Its a pretty good set up.
Just because we dont have the money, not that I would anyway, but swapping with an LS1 motor.
I'll keep my lil 305 TPI.

 

FYI, I recommend you check out moates.net. Craig has a nice selection of DYI software that you can use to tune the motor using a laptop, as well as a selection of do it yourself accessories to burn your own PROM (chip). Be careful, read all instructions thoroughly, and ASK QUESTIONS if you are not sure about any details. I would also recommend you take the butterfly assembly, and do a closed loop on the coolant line (eliminate the flow through). If you haven't, cooler air runs better. There is also a way to do a K&N cold air kit at http://87tagta.tripod.com/coldair.htm On a personal note, I prefer the 305, simply because of it's construction, smaller bore, thicker cylinder walls, and better heat transfer as well. These things tend to incur good longevity from the powerplant. Unless you're horsepower crazy, you can get decent power from it, and expend a little less fuel.

 

thanks for the replys guys. i really will invest in some intake stuff just as soon as i can. as for tpi yes, i do realise that it can be restrictive, but i do like the set up and the response. as well as decent milege!! so many people told me a while ago to "carb it"!! id much rather "LS1" it but not just yet thanks!! does anybody think that the new prom will make a differance? it still has the stock 305 ecu and the 305 hypertech prom.

 

Tune the chip homer

 

Yeah Hypertech, does like nothing at all. It made a world of difference when I had mine custom tuned.

 

Has a 305 to start with stock chip, then goes to a 350 with a cam 1.6 rocks and nitrous and wonders why it doesn't run any better????? Your lucky it runs at all... Get a chip!!!!!!!!!!!

 

of course it doesn't make power like it should, you have the wrong chip in it.
your lucky you didn't burn it up on the dyno with that 305 chip in it, probably the only reason you didn't is because most of the time Hypercrap over fuels at wot. but even if they did over fuel it for a 305, your probably still way too lean for a 350.

burning your own is the only way to go. lots of reading the stickies in DYI-PROM, the AutoProm & a wideband O2 will get you where you need to be.

did you put bigger injectors in it?
if you have to drive it, stay away from WOT & do not spray it.

 

Trap speed?

 

trap speed= 108 (with gas). and i never said it didnt run. it runs really well considering. i didnt realise it could potentially ruin the enginge though, the chip left the states sometime earlier this month, but alas, the shipping company has lost the box it was in????!!! i have however but the new throttle body on today. that has made a big differance. although i think ill stay away from WOT until i get the chip. thanks for the info.

 

As others have said, you're probably running lean with the 18# injectors and stock 305 chip,,, even if you were to jack the pressure up. You need to burn your own chip, or at the least go to a set of SVO injectors and get a stock 350 chip with the 22# injector constant. That'll put your fuel curve a lot closer to where it needs to be than what you have now. DO NOT put a 350 chip in it with the 305 injectors,,, you will run even leaner than you are now. The stock TPI is probably the reason you haven't hurt anything,,, because it is not passing enough air for that combination. You're probably OK to drive it, but I sure wouldn't be spraying it. TPI will work for you, you just need to port the plenum and base and hog out a set of SLP runners or go with a set a AS&M runners if you don't want to do any grinding yourself. I trapped over 109mph with a modified TPI on a flat top 350 with similar heads and a 218/228 cam on engine alone,,, so you have a lot of room to improve on.

 

thanks badss. just to let you know that the injectors ARE 350 tpi injectors, (22#). they were what came with the engine. couldnt use the ecu because it came from a map car and mine is maf.

 

Well if it helps at all, your trap with the gas calculates roughly to:

You are making : 334 HP at the rear wheels and HP at the 394 flywheel*.


I know it's only a calculator, but not a bad "rough" estimate.

http://www.speedworldmotorplex.com/calc.htm

 

Ok,, then you're running too rich with the 22# injectors and 18# constant,, and that's why the 52mm helped instead of hurt. I've seen the cylinder walls washed down from too much fuel in similar situations - the car acts like it hasn't broken in yet,,, and they usually never do once the walls and rings are "glazed". Don't drive it any more than you absolutely have to and pull the fuel pressure down as low as you can until you get a 350 chip. The stock 350 chip for a 1988 MAF car runs $53 at the local Chevy/Pontiac dealer here in the states.

 

i do have the prom from the 350 engine but havent used it because it was out of a map car. could i use it for now until the othe one arrives even though my car is maf?

 

No, you should not use the later MEMCAL.

The ECM is the same for either the 305 or 350 (1227165). The programming is different. The detonation (knock) sensor is different, and using a 305 knock sensor in a 4" bore block can seriously hurt the EST function and cost you power.

It is probably not running lean in normal, closed loop operation, but may be lean at WOT. The HyperScrap programming is all but useless, and typically only affects some temperatures and a bit of timing. You'll do MUCH better on your own.

 

mmm... i think that the knock sensor is a 350. i just thoght that the 350 prm might halp a bit until the custom one turns up. by the way, is motivation any good? they're the ones whos doing the chip.

 

Like Vader said the MAF and MAP ECMs are different and use different chips. You could use a 350 chip for a MAF computer and be closer than what you have now,, like one from an 87 or 88 that matches your gear ratio. The 88 has updates to tuning that the 87 doesn't, that's why I said earlier to see if you can find a chip for a 1988 350 MAF car.

Your car should be noticably rich with the 22# injectors and 18# 305 chip constant you're running now,,, as in eye burning rich at idle (closed loop can only do so much) and sluggish (at WOT with the mods you have you should still be rich with the injector constant off). If not,,, you may have a vacuum leak somewhere that once you get the proper chip could start giving you another problem.

 

damn!! i didnt think all this would be a problam!! i did have an up the pipe test (for the emisions) and it was all fine. would that show wheather or not its running rich?

 

Unless you have the actual test result numbers, a "Passing" rating on an exhaust gas emission test probably won't be useful.

Don't be too surprised if you get an occasional '33' error code while the 305 program is running.

 

I bought a motorvation chip and was real happy with it although it ran rich at first. Had to send it back but at least they give ya a lifetime warranty on it. Gary at Motorvation is a great guy and seems to know what he's doing. Good luck with that chip..

 

so what you're saying is.... you're only keeping your TPI because you think its pretty.

thats basiclly what it comes down to.

no matter how much of a "pretty good setup" you make it... that motor will gain power by ditching that TPI design.

ooh, i moved up to an genIII motor.. i must have forgotten everything i learned the previous 10 years with SBCs....


keep your lil 305 tpi..... but when you want to actually go fast, cheap....(even with SBCs) im usually on here to answer questions

 

TPI isn't for everyone.
a properly done TPI does look better than pretty much any other intake.
why is GM putting covers on so many motors now? because they are ugly.
if it looks good you want people to see it, if it doesn't, you cover it up.
if you have a T-bucket i think either a polished TPI or a chromed out hemi are the only ways to go.
if i was 25 years younger, my car would have an LS7, my truck would be TPI.
but now that im old, im happy with my 14 second TPI car.
if you want to look good, go TPI, if you want to go fast, go LSx.

 

well, we can all agree, dead stock, they're all ugly.... i mean, bare alum, hoses everywhere...ect...

so we're talking about motors that have been cleaned up some...


now, maybe its because i know what im looking at, but i think the LS1 can look a hell of alot nicer. the intake can be painted, the coilpacks can easily be moved....
but then again..... you're probly comparing a dead stock LS1 to a modded TPI car.. (as is usually the case around here)

 

Yes I think it looks pretty good all polished up, Its one of the best looking motors out there. And you dont need to ditch a TPI to make power. Ive seen alot that make pretty good power for what they are. And where do you think they got the design for your LS motor? The TPI maybe?
And I'm glad you have 10 years under your belt.....call me in another 7 years....you might catch up with me. Mostly Pontiac and Chevy motors, thats what i grew up around. I'll give ya pics of what we have now. A 72 Formula, A 71 Firebird, A 69 Vette with the 427/435hp, oh....and the 87 TA.
Some ppl want fast, some ppl want show. I want the 87 Trans Am for show, but its got a little go for a lil 305. Dont try to make fun of me for having a TPI setup......this if a 3rd gen forum ya know. And thinking I know nothing about cars.....Thats another thing.

 

i agree, a LSx can look good if you do something with the intake. the coils on the valve covers don't bother me in the least, in fact i think they look better than the way plug wires look on a gen1 SBC.
the LSxs are better in every way than what the TPIs ever were, except in looks. both dead stock or both all dressed out, the TPI intake still looks better than a the LSx intake.
even the LSx intake i saw that looked like it was chrome didn't compare to a well done TPI.