Boost problems

 :: mods :: Technical

View previous topic View next topic Go down

Boost problems

Post  locht on 10th May 2010, 02:23

Hi all

I have had my 1298cc turbo on and off the dyno a lot lately despite blowing a head gasket we were able to get some pretty good figures 100.2 Bhp at the wheels on 6.5psi measured at the manifold

Problem with this is the more i tensioned the bar on the actuator to try to increase boost i was getting no more boost.
So i measured boost at the compressor housing on the turbo and got a reading of 20psi. I then checked this at the plenum and also got 20 psi.

I have had the overboost valve in the back of the plenum blocked so it cant leak and a new seal kit put in the carb.

Is it normal to lose this much boost across the carb or do i have a leak somewhere i haven't thought of

Cheers

locht

Posts : 8
Join date : 2010-04-21
Location : Queensland

View user profile

Back to top Go down

Re: Boost problems

Post  benjamin on 10th May 2010, 10:31

hmmm , tension in the actuator bar wont really affect boost that much but im unsure of why you are getting such a boost drop :S. The boost drop is normal of about 1-2psi.

set the actuator bar to have about half the hole of tension and use a manual bleed valve of electronic boost controller for boost increase. Have your boost guage and actuator readings from the manifold so its actual boost that the engine see's.
avatar
benjamin

Posts : 181
Join date : 2009-01-28
Age : 30
Location : Leonay NSW

View user profile

Back to top Go down

Re: Boost problems

Post  locht on 11th May 2010, 02:24

i did have a bleed valve coming form the banjo bolt at the top of the manifold as well as the boost gauge but i thought maybe it was bleeding all the air rather than allowing it to register at the gauge

Going to change the way they are connected and see if this helps

locht

Posts : 8
Join date : 2010-04-21
Location : Queensland

View user profile

Back to top Go down

Re: Boost problems

Post  pristic on 29th June 2010, 11:38

Have you sorted your boost probs yet?

pristic

Posts : 4
Join date : 2009-01-28

View user profile

Back to top Go down

Re: Boost problems

Post  locht on 30th June 2010, 02:10

Hi

Yes sorted in a way.

Ended up damaging the engine on the dyno and when i pulled everything apart found a large chunk of crap jammed inside the fitting we were using to measure the boost. Embarassed

This prob means we were pushing a lot more into the engine than realised. Result is three cracked pistons and a 4 thou bend in the crank, all of which is fixable. Im currently waiting on rings for the new pistons and im also getting the flywheel lightened and getting a different grind on the camshaft so should hopefully be all back together in a few weeks

Will keep you posted


locht

Posts : 8
Join date : 2010-04-21
Location : Queensland

View user profile

Back to top Go down

Re: Boost problems

Post  benjamin on 30th June 2010, 11:44

wow that's no good , How did the crank bend?

what pistons where you using , there is a pretty good range for 1293 so you should get some pretty good ones. I guess with unknown boost levels its all too easy to give the motor too much timing . Also who you getting to do the cam?

good luck hope it goes well
avatar
benjamin

Posts : 181
Join date : 2009-01-28
Age : 30
Location : Leonay NSW

View user profile

Back to top Go down

Re: Boost problems

Post  locht on 1st July 2010, 05:39

Hi Ben

Pistons are hypatec (14% silicone) same as the Graham Russell ones
Got the cam done at Waggotts

Not sure how the crank got bent cos it didnt seem like there was much detonation happeningcould have been bent to start with cos i dont think it was checked on first build.

Cheers

locht

Posts : 8
Join date : 2010-04-21
Location : Queensland

View user profile

Back to top Go down

Re: Boost problems

Post  benjamin on 22nd November 2010, 10:31

engine all back together ?
avatar
benjamin

Posts : 181
Join date : 2009-01-28
Age : 30
Location : Leonay NSW

View user profile

Back to top Go down

Re: Boost problems

Post  locht on 22nd November 2010, 23:55

Hey there

Yes all back together and running very well

Making good power at a lot more sustainable level this time

93bhp at wheels and only 3.5 psi

Have done two sprint events and engine has held up well

Was racing it on the weekend just gone and starting to get some good times until a bit of rain came over

Sadly things got a bit slippery and i ended up nose first into a tyre barrier Embarassed

Should only be panel damage engine is fine and dont think ive bent any of the drive train

Will have to put some pics up

locht

Posts : 8
Join date : 2010-04-21
Location : Queensland

View user profile

Back to top Go down

Re: Boost problems

Post  benjamin on 23rd November 2010, 08:11

locht wrote:Hey there
Yes all back together and running very well
Making good power at a lot more sustainable level this time
93bhp at wheels and only 3.5 psi
Have done two sprint events and engine has held up well
Was racing it on the weekend just gone and starting to get some good times until a bit of rain came over
Sadly things got a bit slippery and i ended up nose first into a tyre barrier Embarassed
Should only be panel damage engine is fine and dont think ive bent any of the drive train
Will have to put some pics up

thats great power , now just up the boost a little Smile

no good about the tire barrier your not having the best luck are you Sad

yeh get some pics pics up for sure
avatar
benjamin

Posts : 181
Join date : 2009-01-28
Age : 30
Location : Leonay NSW

View user profile

Back to top Go down

Re: Boost problems

Post  locht on 21st February 2011, 04:25

Hey ben

Finally got some pics up these were after i had it out to a panel shop and put on a car straightener

New panels all done now just have to slap some paint on it

Have also invested in a set of Yokohama A048r's so hopefully should have some good grip now






locht

Posts : 8
Join date : 2010-04-21
Location : Queensland

View user profile

Back to top Go down

Re: Boost problems

Post  benjamin on 9th March 2011, 09:10

looking good , what happened to the front?
avatar
benjamin

Posts : 181
Join date : 2009-01-28
Age : 30
Location : Leonay NSW

View user profile

Back to top Go down

Re: Boost problems

Post  sim_ou_nao on 22nd April 2011, 19:10

Nice work Smile
avatar
sim_ou_nao

Posts : 7
Join date : 2010-09-08

View user profile

Back to top Go down

Re: Boost problems

Post  Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 :: mods :: Technical

 
Permissions in this forum:
You cannot reply to topics in this forum