Inliners International Forums General Discussion Hi Performance Performance Enhancements for a Chevy 250

Good idea.

I was being sarcastic about my last post,he has a lot to learn & has given wrong advise so far as turbo recomendations are concerned.
He asks advise from me,then rejects the ideas ,then turns around & acts like he thought of what I suggest him to do in the first place.

MBHD

Well, since you seem to think you are the only one here that knows anything and everything about turbos, maybe you should write a book to tell everyone what their doing wrong so we will all know how to do it then.

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Why do you think you are the one who gets the "pat on the back". If you have done it, there was probably 10 million others that did it before you did, so why do you think you are special and should get credit for something someone else did before you. There is nothing if life you have ever done that wasn't done by someone else first.

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No, you just think that there are "absolutes" in everything. There are many different ways to do same thing. Just because Tom's solution or combo doesn't align with what you think it should, doesn't mean his is wrong or yours is either. Mighty6's newest combo is a perfect example of this. He is looking to change to a different turbo, but his current one still makes good power and worked fine, but it still doesn't mean that it was wrong for his combo. Just like your cast piston vs. forged piston with a turbo scenario. If someone wants to use a cast piston with high boost instead of a forged piston, and I recommend they use a forged one and you recommend a cast one, it doesn't mean that they will be wrong for using a cast one. Either one will work, again theres no "absolutes".

Again you are wrong, I do not think that way.
All Tlowes advise is from an engine dyno,you cannot only get info from an engine dyno,how many times do I need to say that?

Both you & Tom said basically do not put a supercharger on that guys used cast piston engine,then I say, why not ,then later both of you guys seem to change your minds right on the bulletin board ,that's a called a flip flopper.

The guy did not want to run high boost,he said 5.5 psi,read it again.

Mighty6's combo,you do not know what he is looking for obvioulsy,otherwise you would agree w/his change on the A/R of the turbine housing.
He is not changing his turbo as you stated.
I suggested a long time ago to Steven to use a turbo instead of nitrous & all the problems he had with it.

I told him he would make more power w/a turbo,& be able to drive it on the street if he so desires to.
No I did not pick all his components,or build his engine, but he did ask for advise from me.
He & his brother knows what they are doing & are excellent fabricators I might add. Much respect!!

I did however have a lot of input on parts to use & design in his intake manifold & plenum box.
For the record,I believe His Opala is the fastest car that is on the forum here. 8.6 seconds @ 165 MPH.

I do know what Douglas wants to do w/his Opala/s,set a new record,he finally gave in,to what I've been telling & pleding w/him,,, his turbo specs are off & mostly,the killer in peformance was the camshaft,he now has a little bit better camshaft,but is still using the incorrect turbo.

Not tooting my own horn here but you seem to think I do not know what I am talking about,& that's fine,,,keep it to yourself,thanks

MBHD

Here is an example of me doing something no one has done for a Fazer 700
Carbonfiber gas tank cover.




MBHD

I did recommend forged pistons for the turbo application, and still do, I just am not saying that you are wrong to recommend he use cast pistons. Like panic said in a previous post, you can have 20 opinions on the same topic, and then ask someone else and get a completely different opinion, but that doesn't mean the previous 20 were wrong either.

Cool cover, I make carbon fiber prosthetic feet. Its unreal how strong that stuff is.

I am w/you on recommending forged pistons for forced induction,but if someones wants to try a low boost supercharger or turbochager on a stock engine & does not want to spend little to no money & or has no money,to do so,let them try it out I say,that's how you learn.
More than likely a hard way to learn if not extremly careful.

If the guy wanted to run high boost 87 octane & just slap a blower on,I would not tell him ,try it out & that's it.

Years ago I built my friends 1981 VW Schirocco (SP).
He was on a low budget.
I just reringed & new bearings the engine,ported the cylinder head & used all new gaskets etc.

The pistons & engine were just plain lower compression 1st year 8.5:1 VW GTI 1.8L engine.
The turbo set-up he had was a very primative,it had an imco (SP) valve to control the boost pressure,even that engine suprised me on how much boost it could take ,which was 20 psi.
I added an intercooler from a junkyard Renault turbo fuego.

It was a very quick little car that weighed about 1800 lbs

My friend was ,lets say very frugal when it came to $$$,the hoses wanted to blow off all the time when it went into high boost,all it needed to prevent that was to bead roll the ends on the intercooler tubes.
But that was my first hand experience w/turbocharging & was around the year 1988,since then & actually before then, I always have been interested in learning more & more about turbocharging & supercharging,& Nitrous.

MBHD

What's a normal PSI for boost? Like on a stock 250 with a turbo, wastegate, and methanol injection? I saw a guy run a 250 with 5psi of boost and I think he got like 360hp and about 300 ft/lbs and then I saw a nova run with 16psi of boost and he got 390hp with 401 ft/lbs. If I just had a stock setup with just normal performance upgrades: cam, lifters, springs, intake, exhaust, carb, and turbo, what'd be a good boost for fair longevity and good performance?

Snowman,
The stock lower end will take 4-6 PSI and have a good life. There are many variables to consider.

Rpm range Keep it below 5 K and that will help.

Fuel control- run it lean and engine damage is sure to happen

Detonation/ timing control- 5 PSI will not need alot of timing pulled. Step up the boost and controlling the timing becomes extremely critical.

Performance wise 300-400 hp yes, remember , people get stuck on HP #'s, turbo's really are torq producers. Acceleration in 2nd gear will feel like what 1 st gear used to feel like. Tom

oh and tom. I have a 69 Buick Special Deluxe, not a 72 something I think you said. I made a video of it if you want to see - http://www.youtube.com/watch?v=c6bW41LH47I . You have a nice el Camino by the way.

Nice car! Great for a starter car. Same chassis as a 68-72 chevelle or any GM A body from the same years. Tom

For what your are doing 5-7 psi tops boost pressure.
Your set-up will not make that much HP, but it will make mucho torque,Torque is what you feel move your car ,sort to speak.

You can make 200-260 HP on an engine dyno pretty easy.

Don't need to change the cam,but if you decide to go bigger,just go up to about 200-204 degrees duration @ .050 on a 114-116 lobe center.
Comp cams will make what ever grind you desire.

As far as turbos go,I think you are on a budget & might go w/a used turbo?
If that's the case.

A stock Syclone or Typhoon turbo would be a good size & has a water cooled center section. Or a Buick Grand National 1986-1987 stock turbo.
The Sy/Ty turbos are made by Mitsubishi & the parts are more pricey than the Buick Regal turbos.

Also as a side note there A/R on the turbine housings are nowhere near a .96 which is what was used on a 250 engine dyno.

Don't fall for the "Hype that is a perfect size for a stock 250 that you have basically.
If you do fall for it,you will only be very dissapointed in the streetabilty & poor turbo spool up,,,even w/a manual trans.

Bosanova used a stock modified intake & a stock modified exhaust manifold, pretty clever.
Here is the link https://www.inliners.org/ubbthreads/ubbthreads.php?ubb=showflat&Number=51198&fpart=6
You can also use the stock manifold & run the exhaust pipe up to the turbo wherever you want to place it.

Probably the easyiest,buy a complete draw through turbo set-up from a Turbo trams Am w/a 301 CI V-8
Or the older Buick regals 1978-1980 something.
Post # 188
has a couple pics of the turbo.
http://www.turbobuick.com/forums/before-...ed-equal-6.html
More from the same topic

http://www.turbobuick.com/forums/before-...ed-equal-2.html


MBHD

Something I just considered is if I add the turbo, I'm going to have to pay for premium gas aren't I? But can't I just add a gallon of denatured alcohol which is like 130-140 octane to my tank to raise it to where it needs to be? Because a gallon of denatured alcohol is only like $12. So just fill it near to the top with normal unleaded and then put in that gallon and I should be good to go right? Doesn't alcohol also decrease engine temp? Thanks

Never mind

But if I boost the octane enough using denatured alcohol then shouldn't it prevent it from knocking? My dad used to use denatured alcohol all the time when he raced his friends in his 69 GS 400. He said he would go the pharmacy and buy a pint of denatured alcohol and add it to a quarter tank to drag race. He said it made all the difference.

Gas tank = 16 gallons (just for round numbers)
1 pint added to 4 gallons = 3%
Effect on octane: whatever your imagination tells you

Drugstore: isopropanol (rubbing alcohol)
Hardware store: ethanol + poisonous emetic to avoid the federal liquor tax (denatured alcohol)
Strong anti-knock agent: methanol (wood alcohol)

A better octane boost would be Xylene or toluene 117-116 octane.

Paint stores,Home Depot sells it.


MBHD