Conversion questions

[blander66]

I just picked up a set of turbo manifolds, turbo and injectors, i am starting to plan putting this all in a 94 s-10 Blazer, I know it is going to require some major modifactions, My plan is to keep the CPI and maby convert it to multiport injection, I like the fact that it can be changed from a 180 degree manifold to a 360 degree manifold. I plan on taking the extra set of L35's i have and porting them and pumping up the CC's a little so i have a lower compression ratio.

the questions that i have are
How much tuning do most people have to do to run the comp cams 412(which is very close to the CPI cam)

How much boost could i run safley if im am able to get the compression ration down to 8.9-9.0

What is a good intercooler to use i think the stock one would be a pain with the water pump and such

thanks for any responeses and feedback

 

[jjorgensen52]

Re: Conversion questions

As far as boost, if you have a CMPI motor you're safe for pretty much anything the stock turbo can make.
I am sure you can find someone with a tune for the 412 and whatever turbo / injectors you have

Intercoolers are a big debate.... what kind of use will the truck see? I have an A2A intercooler from Race Proven Motors, but there are many many options

 

[blander66]

Re: Conversion questions

it will still be drive daily, i have the stock typhoon intercooler but i think it would be a pain to make it work with the CPI intake so i figured that a air to air would be better

 

[vortecfiero]

Re: Conversion questions

Im running an L35 block with the Syclone induction system
and my own exhaust manifolds.

I personaly think you should use the stock cam and use the money saved
to setup for some true vortec heads.

The compression ratio is 9:1 on the 94 L35

I am playing with water/alky injection this summer with and without an IC
and hope to see a safe 15lbs... keeping in mind the L35 is a 200hp motor
to begin with.

The engine has seen multiple runs of 12 psi with the air to water IC and a
stock BBZB chip. I plan to use the services of on of the tuners here on
the board

I have done some runs with my wastegate disconnected and compressor
blocked off so its basically naturally aspirated, and found that the CPI
intake gives a ton more midrange than the Syclone. The engine only
started to pull around 4500 and not the rush from 3500 to 5500.

Its my thought that the more midrange you can make, on a non "full out"
engine, the more exhaust velocity and pressure to spool up as soon as
possible. This will allow taller AR ratios or even a larger turbine section.

My thinking is that the 400 hp L35 blocks run into problems because of the
shock on launching from the incredible AWD set up on those trucks. In my
setup the rear wheels will spin at launch or low speed (so I have to be
carful of course) and possibly allow me to run that range of power and not
break stuff through the mid range to 5000 rpm.

Of course this is all theory and if anyone else thinks im headed in the wrong
direction please speak up.

There will be a lot of these engines done and I feel a experienced knowledge
base will help ppl like mself or blander66

 

[blander66]

Re: Conversion questions

i plan on ussing the stock cam, i just asked about the comp cams 412 becasue when i was searching i saw that it was almost the same as the stock CPI cam, for now i think im going to stick with the L35's becasue it already has a set on the engine and i have a extra set, and with the vortecs i woudl have to modify the intake more than i already am going to. I plan on mocking all this stuff up first on one of my extra blocks so the final swap only takes like a weekend

 

[leadfoot]

Re: Conversion questions

My first concern would be knock retard capabilities. If whatever CPU/Module doesn't have a knock sensor, then you could be in for headaches.

I would initially start boost out low and make sure you have adequate fuel pressure and some kind of knock sensing before trying higher pressures.

Any intercooler is better than no intercooler. Just make sure they can handle a certain amount of pressure as some stock/factory intercoolers (eg volvo, saab) can only handle low boost.

 

[blander66]

Re: Conversion questions

Well i almost have the conversion on the CPI intake done, I think i may have found a intercooler that will work but im not sure, I belive it was from a turbo desil from europe shoudl this be enough to cool the engine, how much heat am i looking at needing to reject in Kw for one of theses engines?

 

[leadfoot]

Re: Conversion questions

Your concern should be if the intercooler you intend to use can handle the pressure. Some intercoolers can crack because they cannot handle the higher boost pressures.

Find out what they are pressure rated at before you make a purchase

 

[blander66]

Re: Conversion questions

Your concern should be if the intercooler you intend to use can handle the pressure. Some intercoolers can crack because they cannot handle the higher boost pressures.

Find out what they are pressure rated at before you make a purchase

im not worried about it being able to handle the pressure im just wondering what amount of heat i need to reject for a pretty much stock ty, im more worried about the area of the cooler than it being able to hold the pressure

 

[vortecfiero]

Re: Conversion questions

im not worried about it being able to handle the pressure im just wondering what amount of heat i need to reject for a pretty much stock ty, im more worried about the area of the cooler than it being able to hold the pressure

rule of thumb for a fairly efficient turbo (running in the 60% or higher range) is 12 sq/in per 100 hp at over 60 mph. Most go a little bigger.. or maybe a lot bigger :lol:
so for 400 hp use something like 6 x 8 or 12 x 4 etc. With air to water you can go much smaller.