G10T Performance Mod


New member
Are there any performace parts still out there for the G10T motor.
If so could you point me to any sources.
mike @3tech did alot of custom work for the t3 engines. he is semi retired, does work on the side now...

as for off the shelf performance parts? none.
my t3 is built with re-useable head studs. arp is overkill for these small engines. never had an issues with the oem studs either.
Since I'm in the middle of a G10T rebuild I'm going to add to this thread even though it went cold a month ago.

1. 75 mm Y.C.P. Vitara D16 pistons with NPR or Hastings rings (standard 75 mm). (these are low compression; work great for upping the boost)
2. ARP head studs and main studs
3. Sealed Power Main Bearings
4. KIng conrod bearings
5. I have oversized valves from previous owner ( I will inquire about what these are shortly)
6. I found reference to an MLS head gasket made for salt flat record runs (I found a name listed, but haven't put out a inquiry yet)
7. Zero balance engine
8. ACT or Spec performance clutches
9. Aluminum flywheel Aasco
10. Aluminum crank pullies Thundercloud Performance (he stopped making these, but I think I can still get another; I need one now with AC)
11. Since the rods for the G10T are the same as the 1.3 G13B you can get after market rods (Maxpedding, couple other companies) (overkill)
12. Port and Polish (match to manifold on exhaust)

However, I think the exhaust manifold, turbo, o2 housing, and downpipe redesign is the easiest way to make more power if that is what you are after. The stock log manifold is fine except for the 3 bolt flange to to turbo. The turbo is 31 or 32 mm (I believe the change occurred between MKI and MKII). To make a little more power but sensible I think a hot side inducer turbine diameter of 35 mm to 40 mm would be great. Keep the cold side exducer wheel close to stock. However, if you just want a little more top end I think doing a custom o2 housing to 2 1/2" downpipe to 2" exhaust after 90 degree bend would do the job.
Can I bring this thread back up?
GT4LIFE, I am interested in your MLS head gasket you are talking about.
I'm building a G10T with 76mm pistons, so I would love to know if this MLS is possible to buy in UK.
I want to buy one of these engines to modify to get 180-250hp. I'd prefer 200 with higher torque to push me into seat when accelerating. I'm wondering how much of a difference in weight and size is there between 1.0 and 1.3 turbo and what's easier to modify for higher gains. I am wondering what kind of horsepower can be gained by tuning the ECU? I want a small light engine to drop into an opel gt with decent power.
cannot tune the oem t3 ecu- or at least, nobody has.. would have to go stand alone

the oem turbo set up does fairly good.
a decent port n polish, open exhaust , cam and advanced cam gear do wonders.
Thank you. Do you think my power expectations are achievable or am I more likely to blow the engine up trying?
look up t3ragtop and his posts on the t3 he had built. unfortunately, he is no longer of this world. his cars went on to members on geometro forum and they have made changes since.
The MLS headgasket was mentioned on the salt flat run build. I wrote down the name but never followed up. Now, I cannot find the name but eventually I'll run back into it. More then likely it was a one off.

Making 200 hp on a 1.0 T3 is achievable but not likely destined for longevity. It does not have a forged crank, no purchasable MLS headgasket, displacement while might not seem much is huge when boosting. The DOHC 1.3 for the G13B engine (GT(i)) is a lot better head then SOHC 1.0 or 1.3. Both the 1.0 and the 1.3 are not torque heavy. The 1.3 DOHC can easily make 200 hp and be reliable if you know what you are doing.