Who has found the E85 boost limit?

[sakudog]

I'm wondering if anyone has found the stock engine's boost limit when using E85, assuming you have enough fuel is it possible to cram 30-33psi into the 3.8 with out lifting the heads off the block?

 

[krom]

I know a car that tried 25lbs with a 64 turbo, head gasket blown plus intake gasket was mangled.

 

[sakudog]

I know a car that tried 25lbs with a 64 turbo, head gasket blown plus intake gasket was mangled.

Sounds like a "My buddy story..." do you have any more details? The car was on an E85 setup?

Really looking for direct experience here.

 

[krom]

I was a passenger when it blew, double pumper, stock lines. 96lb injectors, F.A.S.T ECU. Car did 25lbs in 3 gears until the HG blew. Car has been E85 for a year, first time really hammering it with the new turbo from Patrick.

 

[sakudog]

Do 3.8 liters typically blow head gaskets at 25PSI? Was the tuning wrong? 25PSI seems low but I'm new to Buicks and used to different setups.

 

[87chrisss]

I was a passenger when it blew, double pumper, stock lines. 96lb injectors, F.A.S.T ECU. Car did 25lbs in 3 gears until the HG blew. Car has been E85 for a year, first time really hammering it with the new turbo from Patrick.

Something else went wrong do you have a log file of the idc? who tuned the car? new turbo but was the tune up to date? bigger turbo means more airflow.. , i dont think you blew the HG because of the e85 maybe because it went dry and it detonated but blow because of the e85 i doubt it..probably went dry

 

[Phoneguy]

I would be interested to see the timing/RPM being run at the time of the failure and the A/F ratio.

Bryan

 

[krom]

No it was tuned correctly by a well known person, we were not logging the freeway run. The owner thinks it was not enough fuel. The car felt very fast, close to what mine feels like during a 10 second run. I suspect the 105 E85 was not enough octane for the bad air we have in Phoenix.

 

[krom]

I would be interested to see the timing/RPM being run at the time of the failure and the A/F ratio.

Bryan

I think the timing was 22 across the board. The gasket blew not long after the 2-3 shift so the rpm was not an issue. I think it was tuned for 11.2

 

[Phoneguy]

What RPM was the 2-3 shift? I dont run e85 yet so I cant comment on the A/F ratio but it doesnt sound lean. 22* doesnt seem high either. Sucks you dont have a log to see what went wrong.
Been there more than once...my last meltdown was logged, IAT dropped to 62* with ALKY...boost went WAY past 30 psi...it was ugly.

Bryan

 

[NarcGN]

I don't know how far you'll get with stock lines and E85. That could definitely be the problem there.

 

[Phoneguy]

I just re read and saw that the intake gasket was blown as well...Cam/crank sensor checked yet? Valve cover been puled to see if a rocker/spring broke? Timing chain checked?

Bryan

 

[TurboBob]

I run 22 psi all the time, and play around at 25 psi periodically. Have been for a few years. spark advance in the 21 to 23 degree range.

its loads of fun set up like this, so I don't need to push the limits. properly fueled, this boost level is very safe in my opinion.

Bob

 

[krom]

I just re read and saw that the intake gasket was blown as well...Cam/crank sensor checked yet? Valve cover been puled to see if a rocker/spring broke? Timing chain checked?

Bryan

Everything checked and put back together, he is waiting for triple digit temperatures to go away before he takes it out again.

 

[krom]

I run 22 psi all the time, and play around at 25 psi periodically. Have been for a few years. spark advance in the 21 to 23 degree range.

its loads of fun set up like this, so I don't need to push the limits. properly fueled, this boost level is very safe in my opinion.

Bob

You keep playing at 25 psi and you may just bend that HG again.

 

[TurboBob]

the car seems really happy at 26 or so. But the engine is getting tired and I don't have a backup vehicle in case I stretch the gasket too far......

Bob

BTW, I generally run the AFR around 10.5

 

[CGASTON]

You keep playing at 25 psi and you may just bend that HG again.

When did this happen? I was just up there couple of weeks ago and talked to him yesterday. Weird!

 

[Nick Micale]

I run 22 psi all the time, and play around at 25 psi periodically. Have been for a few years..............Bob

Bob, 25 psi periodically may work for your build, your driving habits and your weather?

But with well ported heads with new valves, a 64 MM turbo, a WOT 1/4 mile blast [on the street] with the 2-3 shift at least 6000 RPM at 90 MPH or more, may NOT be the same situation as you encounter in your car.

This GN was probably putting out over 500 HP with at least 25 PSI+, and in my opinion it went past detonation and directly into preignition to totally blow the head gasket wide open and the spark plug electrode was MIA!

Having been the one that changed these head gaskets, and hundreds of others, it looked like an octane problem to me, more specifically LACK of octane. We have run a GN with a very similar build into the high 10's on 116 race gas, and it is still running fine.

There was no other issue in this fresh engine with fuel supply, valve train, tune or anything out of adjustment.

 

[Nick Micale]

When did this happen? I was just up there couple of weeks ago and talked to him yesterday. Weird!

Wrong car Clint.

 

[sakudog]

I'll use this tool to test my E85 here in town, just for safety...my car isn't a DD so it won't be too much of a big deal to me.