86zboss

iTrader: (1)

Exactly right! If you want to be in the 350-400rwhp range, heads, cam and a good tune will get you there WAY cheaper and provide pretty much the same results minus some torque =D

Either way you go, boost, spray or even N/A, pushing the stock internals over 400rwhp is a bad idea, its just a time bomb waiting to explode at the worst possible time.

gregrob

iTrader: (8)

No, not really. I sprayed my stock short block to 500+ RWHP through more bottles than I can remember. The engine is in another car still going strong...

It's all about a well thought out setup, the tune, and a little understanding of what's going on in the engine.

RPMs will kill it a lot faster than making HP. Conversely spraying / boosting too early in the RPMs and making a crap load of cylinder pressure, then mix in a little detonation and bad **** will happen, fast.

Z28Camaro30Ann

iTrader: (15)

I am over 400 RWHP and my motor is fine! Granted the camshaft broke in half a couple weeks ago lmao, but the bottom end is great and it was going for a year and a half with multiple dyno pulls and track passes.

I was at 411 RWHP and 390 RWTQ with a heads/cam/bolt-ons combo and managed a 12.9 @ 110mph last time at the track on a 2.1 60ft. I would say stay N/A and do a good H/C package until you can afford to build it right!

boosted LT1

iTrader: (3)

I had ~90% DC with 42lbs injectors and METH using an ebay T70 which is tiny for an LT1. It was a rearmount iron LT1 and 30 lbs injectors DC was >100 dc with a 4 psi spring.

With just a 306 I'd expect to make >=350 rwhp and consider 30 lbs barely adequate for a decent N/A 306 setup.

I ran an MPT 70 on that rearmount and it was too SMALL. A 70 MM is too small for an LT1!

MPT76 with P trim would be the only turbo I would use. I have a 76 so I will use it but if I were buying the p trim would be my first choice.

I started out cheap like you in Dec 07 so I didn't recently read about a turbo I have had one for years and I'm converting to 4L80E and T76 now. 4L60E lasted until I used slicks and after one launch with slicks it was slpping. In fact I had to pull out so I never even finished 60's with it. So expect tranny work (mine was setup)...the 4L60E made probably 100 1/4 passes on street tires but not strong enough to take the shifts movng a 4400 lb tuna boat.

Good luck

PS Read Zombies posts he will say a 76 is too small unless it is at least a p trim...he has a series of posts on rearmount on LS1.

And my stock motor made a year before valve springs got weak, I pulled the motor and forged it then.

I was told to use a T70 and bought knowing if it was too small I would buy another and use it on my drag car, but unless you can do the same buy a MpT76 p trim and avoid the hassles.

86zboss

iTrader: (1)

The injectors were Ford Racing 30lb redtops. I think they are rated just above 36lb on the LT1 fuel system.

boostedlt1

iTrader: (2)

i'm running the ford racing 42lb'ers on my car and at 7psi they only hit ~72% duty cycle. hopefully they work for my new set-up :/


boosted lt1 - why do you say the t70 is too small? i believe the sts turbo is smaller than a t70? i've heard of a couple people using t70's and seemed to be pleased with them. im just curious what your reasoning is behind it as i almost ran one? did run out on the top end?

LSWHO

iTrader: (1)

I guess taking the turbo out of it's efficiency range will cause more heat in the intake charge than it should?

boosted LT1

iTrader: (3)

I ran a Master Power T70 and with a 8.5:1 191/196 .450/.460 (Iron with 1.6 rockers) the turbo layed down before I wanted to shift. I now changed to a MPT 76 (Bought on here) with a .96 and changed to a 2800 stall with a 4L80E (was 2400 with 4L60E convertor was given to me had brake torque of ~1700).

I HOPE the 76 will hang to 6000 RPM. I run 60 Lbs injectors with Meth I can't recall the DC but it was at least 65% with two stage progressive meth at <15 psi.

IF I were buying a Turbo I would buy a MPT76 with P trim. They are same price as a T76 and would be ideal IMO. The T70 spooled quick you could hear it when climbing a hill on interstate...I expect the T76 to spool ~200 - 400 RPM later and HOPEFULLY not run out, I also changed to a 203/203 .480 and want to shift ~5800 (keep forces low on motor). The motor has stock rods and crank with Probe pistons I use the rearmount as a toy

boosted LT1

iTrader: (3)

Yes the T76 will be more toward the center of the Turbo map BUT a T70 is not bad just I felt I wanted/needed more. I also got the turbo used and could use the T70 on my drag car so changing was not 'expensive'. BUT if you are just starting out better to buy a little larger IMO, the STS systems are designed to spool quickly. Spooling quickly tends to limit the abilty to flow in the upper RPMs.

Yes those are the ones I used. I maxed them out immediately so I suspect you are not making nearly as much hp as my iron LT1 is making.

Edit: I max the MAF ~4600 RPM and ~11 psi. MAF gives an indication of relative airflow and can be used for rough comparisons between setups. My drag car by comparison doesn't max the MAF until ~5500 in first, but obviously flows a LOT more air. It simply comes in later but continues to flow as expected for two MPT70's with .96 exhaust.

License2Ill

iTrader: (1)

Boosted what do u think of this brand:

http://cgi.ebay.com/ebaymotors/3-Per...Q5fCarQ5fParts

They do not accept returns which is not such a great sign...but I imagine many turbo brands do not.

I've lately taken an interest in turbo'ing because I can take it with to almost any later setup if need be.

I'm def. noob to that specific area of rodding..so im still learning.
Why is the ptrim so important...is that the type of impeller design?
what's the diff... betweeen .68 vs .80 or .90?

Is it a big deal to not run an intercooler? If your intake charge is not going to be hot hot? or does the impeller side soak up a lot of heat from the exhuast side of the turbo? Asking because it seems like it's not an absolute necessity...and to learn obviously..... not saying the dozens of installs that do carry it are crazy im just observing it can be done without...please no fires...just share info.

I'd like to work with my stock bottom end for a little while so looking for maybe 420-440rwhp.
all of this is just thought and like I said im still researching and learning for now.
I dont think I need or want a fast spooler....as the LT1 has tons of bottom end torque...I also dont want to spin the little stocker bottom to infinity...so im guessing a medium range to lower highs would work...sounds like Boosted is after similar.....I think this would help a bottom end survive some abuse.

96TransAmboosted

iTrader: (8)

I have seen many sts kits for sale for 1300-2500 that are great starter kits. And 7 psi will be hard without meth and an intercooler. Very do able if the tune is right. Then when it blows go bigger turbo with more boost. You will already have what you need to expand and better your kit. A t 60 or t67 would be a great starter turbo for a stock lt1. Then step up to a 70 or 76 later on. Can be done

Bill Lietzke

WHat kind of heads/ cam/