Help - I Can't Get Boost Over 25#

[XLR8]

I just got back from the track (drove home at 30 MPH 'cause it started to rain and now it's snowing). I can not get the boost over 25#. I have stock heads, TB, MAF, a Thunder Fab I/C and a te44 w/a Precision .63 housing and a heavy duty WG actuator. I was pulling on the actuator until I looked like this . The actuator was on as tight as it would go, if I shortened the rod anymore, I couldn't get it on. Any Ideas? I did, however, run a new best 11.56 @ 113.7 before the rain/snow came - time to update the signature.

 

[azgn]

that may be all she wrote at that altitude...........

 

[XLR8]

I hope not, a new turbo is not in the budget.

 

[azgn]

you are running the sea level equivalent of 10's with that turbo.....what do you want?

 

[Maltman]

Do you mean that you bottomed out the wastegate adjustment rod?? Do you still have threads showing beyond the jam nut?

Remedy = shorten the wastegate rod a touch...not more than you need to pick up the extra boost your looking for. Of course, I never intend on running "low" levels of boost ever again. Take it off the turbo and pinch it down in a vice...get out the hack saw and make sure you have the jam nut on the "uncut" threads so you can clean up the burrs. Put it back together and have fun....worked for me just fine.....but who knows...1 more # and you might be knocking and this would all be for nothing

If that is the case, I've been there.....here's what I did and please make this note: ONCE YOU DO THIS, THERE IS NO GOING BACK!

HTH

 

[Chris McDade]

I would try a HD actuator and see if that helps. My bet is that it would help you, but the only down side is that you can't lower your boost more than 17-18psi. If you don't care about that then go for it.

Good Luck

 

[TS6]

He is already using a HD actuator. My guess would be even if you could turn that turbo up more, wouldn't it be so far out of its efficient operating range that it wouldn't matter?

I'm with Woody on this one......

 

[fitz3820]

I cut my wastgate rod with a Dremel on the car. Just took a bit off so I could get the boost where I want it ~24 PSI w/ my TE-44.

Good luck! Nice times!

 

[NOSjohnWE4]

te-44

That turbo is still 70% efficient at 32psi ...turn it up! Great times, I'd like to see you hit tens with it.

 

[azgn]

it ain't 70% efficient at 5800'!

25 lbs at that elevation is prolly equivalent to 30 at sea level......ever been in a turbo airplane and watch the Manifold pressure as altitude increases? (even tho boost is the same....)

 

[NOSjohnWE4]

yep yep, that's where the nitrous comes in.

ah, to be able to fly an old P51 Mustang...

 

[azgn]

went for a ride in one once (had been modified for the Reno races).......fun ride

 

[XLR8]

I used to live in Reno - the modified P51's were awsome. I can make the rod shorter, but I then it won't streatch to the puck. I'm thinking that the WG is not even opening at all!! Would a larger turbo help or is it time for heads so I can cram more air into the cylenders with the same boost? OR, would more timing help? Maybe 28* or 30* instead of the 26* I'm running.

 

[azgn]

if your turbo is outta gas now, bigger heads would net LESS boost......the only solution is a bigger turbo

you can fiddle with timing and maybe get some more speed out of it


try physically wiring the wastegate shut and check your boost.....could be something wrong with your actuator, but I tend to think you are maxxed out

ps you may have seen the P-51 I rode in...called "FatCat" flown by Clay Claybow and he won at Reno several years running.....this would have been in the early 80's

 

[XLR8]

I'll try wiring the WG shut the next time I have race gas in it.
AZGN - I can't remeber the indiviual planes - it was over 20 years ago - all I vividly remember is a stiff neck for two days and one hellacios sunburn.

 

[xlr8ngn]

AZGN is right about the boost. The atmospheric pressure at your altitude is about 12 PSIA. 25+12/12= 3.08 . 3.08 is your compression ratio. Take sea level 14.7 PSIA and x 3.08 = 45.28 PSIA - 14.7 = 30.6 PSI in gauge pressure.

 

[RabidHamsterFab]

I know this is an old post and I don't know if the problem was rectified.. but...

high boost #'s are fun to spout off.. but the power is the airflow not the psi #

if you don't have better manifolds/exhaust, ported heads, cam, lifters, intake etc etc etc... do it..

especially at that high of an altitude your engine is crying for oxygen... do everything you can for it to breath better... if you can get the same amount of air in faster and easier.. you turbo doesn't work as hard (and doesn't heat the air quite as much) .. and you make more power with even more room for advancement later when you can afford a larger turbo ... also at that altidude a lil more advance prolly wouldn't hurt .. but I wouldn't do it more then a degree at a time