Has anyone used the TTI lower compression head gasket? I am preparing to go turbo and would like to keep my stock internals. Is it worth it? Are there any leak problems? What can you boost up to with stock internals? Is TTI the only company that makes one of these?

I think lowering the stock compression is a great way to get more boost from a stock engine. Joe A. Ran 12psi for a year on a HRC Stage II with stock injectors using a thicker headgasket as his only extra parlor trick. This is not a guarantee that it will work for you, but I like the concept. What is the material of the headgasket? I have a copper one and you hear that argument go both ways about sealing vs strentgh vs necessary. A trick Chrysler did on their first prototype Neon turbo was to stack two MLS gaskets to lower the compression.

Here is the link to the company that makes this gasket. All the info is there. It is for a Neon, but will fit our car.
http://www.ttiracing.com/neonproducts/headgasket.htm

How long to install one? I know it is difficult, right?(might as well replace timing belt while at it?)

man if your gonna change the headgasket you might as well rebuild the engine.... save you money in the future, hehe like get new rings if your compression is low.

That looks like a really nice gasket actually. It is made of the same material as the stock gasket only thicker. Might be worth a try if you are willing.

Changing a gasket is FAR easier than a rebuild. You can do the gasket change in one afternoon and yes, it is like doing a timing belt.

Out of curiousity does anybody know how much thicker the TTI racing gasket is than the stock gasket?

"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein



Michael J. Kulaga
e-mail: Michael_97RS@2gntDSM.zzn.com aol IM: MJKulga
http://highlander.dsmpower.com/

Injen CAI, 55mm TB, Hooker 4-1 Stepped Header, GS-T Muffler, AFX UDP, S-AFC, 8.5mm Magnecor Wires, Crane Fireball HI-6DI2, SS Clutch Line, NRG Susp. Motor Mount Ins., FU/RU/RL STBs, TSW Blade 17x7.5, Bridgestone Potenza RE730 215/45ZR-17. Front KVR Cross-Drilled Rotors & Carbon Fiber Pads

To Be Installed: Ported/Polished Intake Manifold 1/2, Rear disc brake conversion kit w/, Rear KVR Cross Drilled Rotors & Carbon Fiber Kevlar Pads, SS Brake Lines

I called TTI and the guy told me that the gasket was 90/1000 of an inch. First of all, why would you say 90/1000 instead of 9/100. Second, that dosn't sound very thick to me. What do you guys think?

.090 is 90/1000 and the stock gasket is .046 which is 46/1000

________________________________________________________________________________________
current status - No 3rd Gear synchro


http://hometown.aol.com/ohshootuhh/
www.Fast420A.com

the light has been shown

The gasket is actually .090 thicker than stock

So it's .136 inches thick? That seems a LITTLE thick. Have you had any problems with the high boost levels blowing out the thick gasket?

Also can you make thinner headgaskets in MLS ? Around .020 - .030 ?

________________________________________________________________________________________
current status - No 3rd Gear synchro


http://hometown.aol.com/ohshootuhh/
www.Fast420A.com

Fast420A, that extra thickness would drop compression by a full point which is why I suspect he did that. You would have 8.6:1 on a stock head. Instead of a thinner gasket for your application, why not just shave the head? I would be concerned of something thinner blowing out.

The less I have to shave off the head, the better. Thats why I am looking for thinner but I didn't want to have to use a copper one. I may not even shave the head at all and stick with the stock gaskey also. Not completely sure yet.

________________________________________________________________________________________
current status - No 3rd Gear synchro


http://hometown.aol.com/ohshootuhh/
www.Fast420A.com

Okay we need to look into what rally needs to be shavd off the head for compression increase...

If .090" added reduces 1.1 Compression points... Does that amount need to be shaved off for a 1.1 C.R. increase? If so that's about double what we thought? And that's between 1/16" and 1/8" That's geting up there in removed material... And that's ust for a 10.5:1 C.R. Hmmm.... thoughts?

"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein



Michael J. Kulaga
e-mail: Michael_97RS@2gntDSM.zzn.com aol IM: MJKulga
http://highlander.dsmpower.com/

Injen CAI, 55mm TB, Hooker 4-1 Stepped Header, GS-T Muffler, AFX UDP, S-AFC, 8.5mm Magnecor Wires, Crane Fireball HI-6DI2, SS Clutch Line, NRG Susp. Motor Mount Ins., FU/RU/RL STBs, TSW Blade 17x7.5, Bridgestone Potenza RE730 215/45ZR-17. Front KVR Cross-Drilled Rotors & Carbon Fiber Pads

To Be Installed: Ported/Polished Intake Manifold 1/2, Rear disc brake conversion kit w/, Rear KVR Cross Drilled Rotors & Carbon Fiber Kevlar Pads, SS Brake Lines

Maybe I have it recorded wrong, but I have the HG thickness as .040

anyways, here's the numbers

If it is .040:

Gasket of .130 gives CR of 7.6:1
to raise comp 1 pt, give gasket thickness of .0079 or mill off .0321

If it is .046:

Gasket of .136 gives CR of 7.6:1
to raise comp 1 pt, give gasket thickness of .0139 or mill off .0321

So, it appears the stock thickness doesn't matter if it's .040 or .046 b/c the rounding accuracy will mask the differences. But, dropping CR 2 points seems a little too much to me. To drop it to 8.6, we need a gasket thickness of .0856.

Matt

And that jives a lot closer to what I have for milling specs, etc. But TTI Racing says their Headgasket only lowers compression 1.1 C.R.??? Not the 2 or so I would expect.

"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein



Michael J. Kulaga
e-mail: Michael_97RS@2gntDSM.zzn.com aol IM: MJKulga
http://highlander.dsmpower.com/

Injen CAI, 55mm TB, Hooker 4-1 Stepped Header, GS-T Muffler, AFX UDP, S-AFC, 8.5mm Magnecor Wires, Crane Fireball HI-6DI2, SS Clutch Line, NRG Susp. Motor Mount Ins., FU/RU/RL STBs, TSW Blade 17x7.5, Bridgestone Potenza RE730 215/45ZR-17. Front KVR Cross-Drilled Rotors & Carbon Fiber Pads

To Be Installed: Ported/Polished Intake Manifold 1/2, Rear disc brake conversion kit w/, Rear KVR Cross Drilled Rotors & Carbon Fiber Kevlar Pads, SS Brake Lines

Here's what I copied and pasted from my excel spreadsheet. The first column is stock. the second is changing the gasket to see what CR you get. The third is changing the CR to see what your gasket thickness needs to be.

Head Gasket t vs. CR Calculator
Stock D Gasket D CR
bore(mm) 87.5 87.5 87.5
stroke(mm) 83 83 83
Gasket t (in) 0.046 0.1360 0.0856
Head + Gasket 207956.6 262941.41 232137.67
Head C Vol 179853.3 179853.35 179853.35
Comp Ratio 9.60 7.59 8.60

Gasket thickness of 0.1360 gives CR= 7.59
Compression Rat of 8.6000 gives Gt= 0.0856

...
matt

Azizi,

There are alot of numbers being thown around. What do you think?