larger turbo upgrade question
 

I have a 86 951 with Lindsey 3" exhaust, manual boost controller (running about 15psi), Lindsey dual port wate gate, Lindsey boost enhancer, and Autothority Stage II chips. The turbo, airflow meter, and injectors are stock. The car runs great. I have never dyno'd it but I would guess it must be at least 260-270 at the wheels. That being said if I were to buy a larger turbo and maybe a MAF/injectors to go along with it do you think the change in performance is going to be "holy crap I can't even keep the wheels hooked up" or "holy crap why did I just waste 2000.00$ to have a slight gain with more turbo lag" ! I am sure some of you guys out there may have wondered about this also. What do you think? Buy a bigger turbo and chips to go along with it and leave the stock airflow meter alone and see how it goes??? Sorry for so many details but it would be nice to know what upgrades are really worth doing.

Thanks all,
SONNY

Re: larger turbo upgrade question
 

well i am thinking it would be holy crap i cant believe how fast my car is now. now as for hp numbers go here is an estimate for you:
my 87 951 has LR stage 2 maf with mafter burrner, chips, electronic boost controller set at 17 psi, hard pipes, 3bar FPR, MSD blaster coil, performance wires, a/c delete kit LR 3" exhaust w/no cat and magniflow muffler, stock waste gate that works as designed (not failing). i am putting down 236 at the wheels on a mustang dyno. tq is somwhere about 276 i think 3100rpms max hp was achieved at about 55-5600 rpms. also my turbo is leaking oil and needs to be rebuilt. so from what i have read yes getting a new turbo will deffinatly increase your power it just depends on how big of a turbo you get.

i have to respectfully disagree. you can make a bunch of power with a smaller turbo. the limits of the power your turbo can make has to do with the size, but you don't automatically make more power with a larger turbo unless you have tuned the ignition timing and added the fuel to go with it... i'm sure that's what he meant though!

I'm sure when he's upgrading turbo he's going to upgrade to russell's maxtronic, or buy some 951max chips ;)

well as for the stock non "s"turbo goes i am at the limit with how much power i can get out of it. and yes i did not say anything about more fuel or timing, i shoudl not of assumed that everyone would know about that.

I have a buddy that bought a car with a bunch of stuff done to it but wasn't running. After he got it running it was essentially stock but with 3" exhaust and big turbo (don't know exact specs). He even has stock chips in it running stock boost. His car is scary fast compared to my car (stock with LBE). The turbo on his car makes all the difference. First and second gear are just about useless when WFO and the boost hits...
Makes me think the turbo on my car will be the first change...

When you do yours, replace your chips AT LEAST.

You should be replacing your injectors, and your fuel pressure regulator.

I bet your friend is running his car too lean, which DOES put it at risk.

See, with the larger turbo more air is being shoved into the cylinders. But with stock chips the ECU isn't even trying to shove enough fuel in there to make it more effecient, essentially it's being starved of fuel.

The chips will compensate for this and they will attempt to shove more fuel in there. However, stock injectors were made for the stock turbo, as was the fuel pressure regulator. All in all, a FPR costs about $60. Injectors about $400. Chips about $250.

But you will even be faster (and safer) than him :D

-Alex

His car does have a 3.0 FPR on it. Since he is running stock boost, the computer doesn't care what turbo he has on the car. The computer has already measured all the air before it gets to the turbo. The stock injectors are good for close to 300hp so I won't need injectors for a while.

well then it shouldn't be any faster than your car. if the pressure is the same, even with a larger turbo, then it should produce the same power. the maps will be off, because it will spool differently and the chips are set for a stock turbo. if it is larger it probably spools slower but will retain full boost longer. what you are saying doesn't make much sense.

the only thing i agree with is that the stock injectors are good for more power than the car produces stock, i just don't know how much exactly. your buddy should get chips to match his setup, and if you do upgrades and get chips to match you will safely be making more power than your buddy.

i would deffinatly have to disagree with this state ment as a bigger turbo will produce more power at the same boost levels. hence the turbo s vs the non "s" mine with more mods creats less hp than a "s" at the same boost level. also just look at the stock numbers. 217 vs 240? a bigger turbo is pushing more air than a smaller turbo so it will make more power. i know i could change out my turbo now for a larger one with the same boost level and gain 100hp it just depends on how big of a turbo you want and how much lag your willing to deal with.

If he's running stock boost, I hope he's got either a small turbo or a LARGE hotside to get spool quickly.

Or he won't be any faster than you.

Either way, his fuel and ignition maps are off for turbo spool times. Remember the DME has no idea what the turbo is doing. Only the KLR does. This means that it is not changing the maps for more or less boost depending on where the rpms are. It's static as far as boost is related.

-poz

Re: larger turbo upgrade question
 

you should not be using both a manual boost controller and a boost enhancer.

boost enhancer with manual controller
 

I checked with the Lindsey Racing brothers about using both components together. They said it was no problem and that some of their customers liked using both together. You just need to set your max boost with the manual controller first. I driven the car with and without the LBE and it seems to hit harder with it installed.

of course lindsey will say you can use both, it's more sales for them.

if you understand how the LBE and MBC work, you will understand that you should not use both.

what MBC are you using?

LBE with Lindsey MBC
 

Should I NOT be using both of these? I've never seen more than 15psi on my boost gauge with the current setting on my MBC. I never see any overboost or even spikes above 15psi on the boost gauge. I thought it was a matter of the different "rates" of opening of the wastegate (with and without the lbe)
If I don't go over 15 lbs of boost what else matters?? I am interested in this now.

Thanks, Sonny

what MBC are you using?

that's a pretty dumb argument, to say that porsche just put in a larger turbo and WHABAMM more horsepower. of COURSE they tuned the ignition/fuel maps to compensate. also, perhaps you don't know what turbo the S uses, but it has a larger HOT (exhaust turbine) side than a larger compressor section (which i believe is what you are proposing to use or that was used just to get more power. a larger hot section will make the boost come on a bit later, as it takes a tad longer for the exhaust to spin a larger wheel on the exhaust, but it will be able to push the compressor harder at higher rpms without slowing down, making more power (how porsche derives more horsepower from the same compressor section & upgraded ignition/fuel maps). just putting a larger compressor will limit you when that exhaust turbine maxes out (why boost levels on a 26/6 drop off at high rpms without enhancement). you really need to read up on how turbine systems work...

MBC used with LBE
 

Nize,
I am using the basic 69.00$ Lindsey manual boost controller with the locking knob, and the Lindsey dual port wastegate.

Thanks,
Sonny

okay it makes sense why you need both now. the lindsey single knob MBC is crap. what you should do is get rid of the lindsey boost enhancer and controller, and replace it with the accuboost single unit (it's cheaper too!);
http://www.boostsciences.com/accuboost.html

a good boost controller will eliminate the need for the boost enhancer, as the controller will perform that function. the accuboost does that.

however, i'd advise not using a manual controller altogether, and go to electronic for maximum performance and failsafe.

whoops, posted in the wrong thread
 

Ok Nize, ERAU944, and others. Looks like I'm getting lots of good 951 gearhead info here with this question at the beginning of this thread. As far as using the Lindsey Boost Enhancer WITH my Lindsey Manual Boost Controller, if any of you are recommending not to do this then I'll pull it out. Back to the original question : Lets say I want more out of this engine for the "STREET" and want to buy a turbo that I can bolt on, throw a different chipset in the dme, injectors, then drive away with pump gas with a decent gain......... ..not having just spent 4000.00$ to get 300ft/lbs at the wheels. Which turbo would you guys recommend ??? A " turbo S" model, a Lindsey xxxxx, a powerhaus?

(at some point the LS-1 conversion vs the expense of a modified 951 engine are in equilibrium)

Thanks all,
Sonny

it's more complicated than that. what is your ultimate goal ?

most hp for the buck?
how about reliability? are you willing to blow up your car to attain this goal?

figure out what you want first, then find out how to get there.

Yea I know, it is a tough question. Maybe I'll leave the car alone and be happy with the way it runs now. But the quest for torque/hp never goes away does it :) Like when I had an early 911 and changed the engine 3 times from 2.4 to 3.0 to 3.2 !!

(I'm not sure if I can use that accuboost controller with my dualport wastegate. ??? I headed to their site now.)


Thanks,
Sonny

well if you're going at it like that, i would buy something that is capable of a lot, then start at the low end of the power available and tweak a little every so often. seems like a lot of trouble to go to, geez three engine changes! i see a lot of people looking for more horsepower, but why on earth do you need it? i know it's nice to go fast, really fast, i just can't find anywhere to use the power on the street. the 944 gets me in enough trouble as it is...

i've never desired more horsepower from my 944, and i doubt i will modify my 951 (if i hadn't had the opportunity to buy it so cheap i probably wouldn't have). i never have and never will understand this 'horsepower craze'. sure more power is nice, but power is nothing without control. so for now i'll attempt pushing (on the track) the envelope of the 944, and then move on to the 951... in stock forms.

crazy with mods
 

Mike you need to email me more to bring me to my senses! You are so right about not being able to really use big HP on the street ! We all know this but continue to press on with the performance mods. What I should do is trade my 951 for a small Kubota with a front loader. :)

Sonny

What ever floats your boat, some people love it, some people want a 'quick' car.

To all his own :)

we don't all continue to press on with performance mods. if i'm ever in need of more performance, i'll modify. for now, i'll learn to use what i have.

enjoy your car, i'll enjoy mine

love, peace, n chicken grease!

be prepared to bring some cash with you if you are going to trade up to Kubota. They start at $14,000 for one with a front end loader on it. Heck you can buy alot of 951 for $14,000.

My vote is for you to crank out a LS-1 swap then add a turbo to that. You will have more HP available than you could ever want or need.

Speedy:)