Supercharging an 86
Thread Starter
Team Owner
Joined: Mar 2001
Posts: 30,856
Likes: 293
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Supercharging an 86
thought you might want to chime in
http://forums.corvetteforum.com/c4-t...questions.html
http://forums.corvetteforum.com/c4-t...questions.html
Hi guys,we just bought a Vortech v2 Supercharger for a friend of mine
He is doing a fresh build,TPI Based on a 4 bolt 1991 block.-
He also bought a set of 113 heads.-
This is the pic of the previous car where the supercharger was installed :
This is what we are getting :
My friend has the ZZ4 Cam and springs
Forged pistons and rods and fresh everything !
He is real happy about it and this will be a good learning experience.-
Ok here we have some doubts and im sure we are on the start of a long way.-
1 - Does he need a special timing retarder or something ?
2 - He bought FIC's Bosch III 22 lbs,does he need bigger injectors?
3 - He will do work on the 113's,what valve size is recommended for
this application?
4 - He will do work on the 113's,what combustion chamber size is recommended for this application?
5 - How is the proper way to reduce compression to make the supercharger work correctly ?
Do you guys have experiences with this Supercharger ?
More info here
Any advice / help is greatly appreciated !
as a point aside :
His 86 will get my 89 set of wheels (former bd2626's) and adapters
since im getting the Fikses mounted ! ! !
This will be the supercharged beast !
He is doing a fresh build,TPI Based on a 4 bolt 1991 block.-
He also bought a set of 113 heads.-
This is the pic of the previous car where the supercharger was installed :
This is what we are getting :
My friend has the ZZ4 Cam and springs
Forged pistons and rods and fresh everything !
He is real happy about it and this will be a good learning experience.-
Ok here we have some doubts and im sure we are on the start of a long way.-
1 - Does he need a special timing retarder or something ?
2 - He bought FIC's Bosch III 22 lbs,does he need bigger injectors?
3 - He will do work on the 113's,what valve size is recommended for
this application?
4 - He will do work on the 113's,what combustion chamber size is recommended for this application?
5 - How is the proper way to reduce compression to make the supercharger work correctly ?
Do you guys have experiences with this Supercharger ?
More info here
Any advice / help is greatly appreciated !
as a point aside :
His 86 will get my 89 set of wheels (former bd2626's) and adapters
since im getting the Fikses mounted ! ! !
This will be the supercharged beast !
Supporting Vendor
Joined: Mar 2008
Posts: 1,762
Likes: 14
From: Cumming Ga
looks like we will be seeing alot of post from you on the progress. The 22's he got from us are too small for this.. I will credit him 100% on the right size.. Need to know how much boost? Is he upgrading the pump?
Jon
Le Mans Master
Joined: May 2007
Posts: 8,448
Likes: 27
From: Valparaiso
We don't have no idea about the boost
is it something you can regulate at the supercharger or something ?
i'e always wondered how to regulate how much boost ...
I don't know if this comes with a new pump or not
Does he need a new pump ? Is it better to get a new one ?
Thanks again !
Supporting Vendor
Joined: Mar 2008
Posts: 1,762
Likes: 14
From: Cumming Ga
Thanks Jon !
We don't have no idea about the boost
is it something you can regulate at the supercharger or something ?
i'e always wondered how to regulate how much boost ...
I don't know if this comes with a new pump or not
Does he need a new pump ? Is it better to get a new one ?
Thanks again !
We don't have no idea about the boost
is it something you can regulate at the supercharger or something ?
i'e always wondered how to regulate how much boost ...
I don't know if this comes with a new pump or not
Does he need a new pump ? Is it better to get a new one ?
Thanks again !
Le Mans Master
Joined: May 2007
Posts: 8,448
Likes: 27
From: Valparaiso
UPDATE: The whole thing comes with its pump.-
Yes this will be a good nice ride !!!!!!!
the SC bug bits me a bit ..but ..with my High compression and Hypereutectic pistons
i guess i won't do it on my 87..or maybe add a little little 4-5 psi boost....
Yes this will be a good nice ride !!!!!!!
the SC bug bits me a bit ..but ..with my High compression and Hypereutectic pistons
i guess i won't do it on my 87..or maybe add a little little 4-5 psi boost....
Melting Slicks
Joined: Jan 2002
Posts: 3,293
Likes: 79
From: Jackson MI
The injectors may not be too small. Is this guy planning on using the FMU provided with the kit. If so you'll need to check and find out what the psi/# of boost increase is for the FMU as to which injectors you would use.
If he is not going to use the FMU then he would definately need bigger injectors. As most people will tell you the FMU is just a bandaid for not having the proper sized injectors and they do fail on occasion. It would be wise to upgrade the injectors, and the fuel pump while you are at it. A walbro 255lph should do him just fine.
If he is not going to use the FMU then he would definately need bigger injectors. As most people will tell you the FMU is just a bandaid for not having the proper sized injectors and they do fail on occasion. It would be wise to upgrade the injectors, and the fuel pump while you are at it. A walbro 255lph should do him just fine.
Melting Slicks
Joined: Jan 2002
Posts: 3,293
Likes: 79
From: Jackson MI
if you are planning on having the ECM reflashed then you don't have to worry about anything to do the timing. With a supercharger the boost will be related to RPM so they can put it in the tune. If you want flexability to play with it then you would have to get an external box. A vortec BTM is a good choice, it will retard a certain amount for each pound of boost you have up to a certain amount.
The FMU is the device that raises fuel pressure depending on how much boost you are running. So instead of lengthening the pulsewidth of the injector is just increases the fuel pressure to get more fuel into the engine. Its the blue circle thing that has two braided steel lines comming out of it and one small rubber vaccume line. In the picture above its the part that is sitting in the fender. If you go to larger injectors then you don't need this part.
The FMU is the device that raises fuel pressure depending on how much boost you are running. So instead of lengthening the pulsewidth of the injector is just increases the fuel pressure to get more fuel into the engine. Its the blue circle thing that has two braided steel lines comming out of it and one small rubber vaccume line. In the picture above its the part that is sitting in the fender. If you go to larger injectors then you don't need this part.
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Supporting Vendor
Joined: Mar 2008
Posts: 1,762
Likes: 14
From: Cumming Ga
if you are planning on having the ECM reflashed then you don't have to worry about anything to do the timing. With a supercharger the boost will be related to RPM so they can put it in the tune. If you want flexability to play with it then you would have to get an external box. A vortec BTM is a good choice, it will retard a certain amount for each pound of boost you have up to a certain amount.
The FMU is the device that raises fuel pressure depending on how much boost you are running. So instead of lengthening the pulsewidth of the injector is just increases the fuel pressure to get more fuel into the engine. Its the blue circle thing that has two braided steel lines comming out of it and one small rubber vaccume line. In the picture above its the part that is sitting in the fender. If you go to larger injectors then you don't need this part.
The FMU is the device that raises fuel pressure depending on how much boost you are running. So instead of lengthening the pulsewidth of the injector is just increases the fuel pressure to get more fuel into the engine. Its the blue circle thing that has two braided steel lines comming out of it and one small rubber vaccume line. In the picture above its the part that is sitting in the fender. If you go to larger injectors then you don't need this part.
Le Mans Master
Joined: May 2007
Posts: 8,448
Likes: 27
From: Valparaiso
Thanks Jon and mn !
We'll find out what's the PSI when we get the SC here.-
Any recommendations on engine preparation or something ?
Valves ? or other issues,we are looking to make it right...
omg...the sc bug is biting me as well !
We'll find out what's the PSI when we get the SC here.-
Any recommendations on engine preparation or something ?
Valves ? or other issues,we are looking to make it right...
omg...the sc bug is biting me as well !
Melting Slicks
Joined: Aug 2003
Posts: 3,399
Likes: 394
From: Lakeville MI
With a 3.5" pulley, an S-trim should make roughly 6-8psi between 5,000 and 5,600 rpm on an otherwise stock L98. More revs or a smaller pulley will result in additional boost.
For fueling a supercharged L98 MAF car you have a range of options available (ranked roughly in order of cost):
42 lb injectors should be suitable for up to approx. 12 psi, but the key is in the tuning. My preference would be for option #3.
For fueling a supercharged L98 MAF car you have a range of options available (ranked roughly in order of cost):
- 42 lb injectors + intank pump + Blowerworks custom tuning for 165 ecm
- 42 lb injectors + intank pump + 2 bar map sensor + holden $5D based custom tuning for 165 ecm
- 42 lb injectors + intank pump + Blowerworks custom MAF + custom tuning for 165 ecm
- FMU + small injectors + intank pump + booster pump + custom tuning + crossed fingers
- 42 lb injectors + intank pump + 2 bar map sensor + 730 ecm conversion + $8D, $58 or $59 based custom tuning
- 42 lb injectors + intank pump + 2 bar map sensor + Kalmaker Australia custom tuning for 165 ecm
- 42 lb injectors + intank pump + 2 bar map sensor + full aftermarket ecm and custom tuning
42 lb injectors should be suitable for up to approx. 12 psi, but the key is in the tuning. My preference would be for option #3.
