Tuning tips for IROC-Z 220HP TPI 5 speed 1988
Thread Starter
Junior Member
Joined: Oct 2011
Posts: 23
Likes: 1
From: Nybro, Sweden
Car: Iroc z28 1988 total odo 33.000miles
Engine: 305TPI 220 HP
Transmission: 5 speed manual
Tuning tips for IROC-Z 220HP TPI 5 speed 1988
Hi Guys !
Here in Sweden we have higher octane 95-98, wich would allow a later tune on the ignition I would guess.
But, what do you say as pro´s,
Will I loose high rev Power if tuning it to a later timing, will I gain low rev torque by the later ignition timing.
It is mainly a summer enjoy car, so fuel economy is not the most important, but a maxxed Power performance would be nice.
Any tips re timing figures etc , and how to do it, that is do I have to turn something off while fiddling with the timing , or so...
You can answer the post or send direct to bo@neckmike.com if you like, Thanks !
Best Regards from
Bo in Sweden
Here in Sweden we have higher octane 95-98, wich would allow a later tune on the ignition I would guess.
But, what do you say as pro´s,

Will I loose high rev Power if tuning it to a later timing, will I gain low rev torque by the later ignition timing.
It is mainly a summer enjoy car, so fuel economy is not the most important, but a maxxed Power performance would be nice.
Any tips re timing figures etc , and how to do it, that is do I have to turn something off while fiddling with the timing , or so...
You can answer the post or send direct to bo@neckmike.com if you like, Thanks !
Best Regards from
Bo in Sweden
Last edited by Camaro Bo; Feb 21, 2014 at 10:52 PM. Reason: new thinking
Supreme Member
iTrader: (3)
Joined: Feb 2003
Posts: 2,470
Likes: 6
From: Waterford, MI
Car: 1998 Camaro Z28
Engine: 6.0L
Transmission: 4L60E
Axle/Gears: 3.73
Re: Tuning tips for IROC-Z 220HP TPI 5 speed 1988
If you just want to adjust the timing, there is a connector that sticks out of the wire harness above the heater box under the hood. It is 1 wire that is brown with a white stripe. Disconnect that, then start the car and adjust the base timing. When you're done, shut the car off, plug it back in, and take it for a drive.
Thread Starter
Junior Member
Joined: Oct 2011
Posts: 23
Likes: 1
From: Nybro, Sweden
Car: Iroc z28 1988 total odo 33.000miles
Engine: 305TPI 220 HP
Transmission: 5 speed manual
Re: Tuning tips for IROC-Z 220HP TPI 5 speed 1988
Thanks DrDave88 for the tips !
Anybody who has thinkings re timing late / Normal / early as for the 95-98 octane, as for Power timing , better torque timing etc
//Bo
Anybody who has thinkings re timing late / Normal / early as for the 95-98 octane, as for Power timing , better torque timing etc
//Bo
Re: Tuning tips for IROC-Z 220HP TPI 5 speed 1988
Within practical limits , better fuel will allow you to run an earlier , or more advanced , timing point . The earlier (again , within practical limits) you can light the mixture the more complete the burn and the better the push on the piston . A later , or retarded spark , will compensate for lesser quality fuel , but at the cost of power .......
Thread Starter
Junior Member
Joined: Oct 2011
Posts: 23
Likes: 1
From: Nybro, Sweden
Car: Iroc z28 1988 total odo 33.000miles
Engine: 305TPI 220 HP
Transmission: 5 speed manual
Re: Tuning tips for IROC-Z 220HP TPI 5 speed 1988
Thanks Init4fun,
In my mind it would have been the other way around,
that bad fuel forces one to have earlier timing to avoid knocking,
and that higher octane allows an later ignition as the fuel does dot as easily self-ignite as the low octane fuel.
so one have new things to learn every day
Thanks !
Bo
In my mind it would have been the other way around,
that bad fuel forces one to have earlier timing to avoid knocking,
and that higher octane allows an later ignition as the fuel does dot as easily self-ignite as the low octane fuel.
so one have new things to learn every day
Thanks !
Bo
Thread
Thread Starter
Forum
Replies
Last Post
Sanjay
Engine/Drivetrain/Suspension Parts for Sale
1
Aug 12, 2015 03:41 PM








