L98 budget engine upgrades. Will it work?
Safety Car
Joined: Sep 2001
Posts: 4,137
Likes: 531
From: Glenbeulah Wi
Sounds like I might be opening up a can of worms here if I replace the cam. Maybe I'll plan around the mods you mentioned. As long as I get to 280-300CHP I'll be happy. Would building around a hyd flat tappet cam be more beneficial? Apologies if that's a stupid question. Once we get into the more technical stuff, I have no idea.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
I own a Vette (L98) and an IROC-Z (LB9), both '88s and I could literally swap the intakes, save for possibly some bolt angle issues. In fact, when I suspected a faulty MAF in the Vette, I simply swapped in the MAF from the IROC-Z.
When I built up my prior '88 Vette I installed a slightly larger TB, ported the plenum & runners as well as Siamesed the lower runners into the intake base. These mods allowed the engine to pull pretty well to 6k rpm, as shown on the dyno pulls.
When I built up my prior '88 Vette I installed a slightly larger TB, ported the plenum & runners as well as Siamesed the lower runners into the intake base. These mods allowed the engine to pull pretty well to 6k rpm, as shown on the dyno pulls.
Drifting
Joined: Nov 2009
Posts: 1,341
Likes: 2
From: Perth Western Australia
St. Jude Donor '10
I am in Perth Australia and did the top end upgrades about 6 years ago on my 87 convertible. It was a great project to learn about the C4. I had a lot of help from forum members which I am very grateful for. I did the cam and heads as well as the intake / plenum. I went the superram route. I also went for a hiflo cat and long tube headers. I sourced components from the US, Canada and Australia. I also had a go at tuning it myself. Cost me about $7500 all up but that was when the Aussie dollar was on parity with the greenback. I also had all the emission control removed. My gearbox has now also been shiftkitted and beefed up. I also put some reconditioned injectors in.
I sold my refurbished and skimmed stock ally heads to a club member locally for $1000. He got a good buy I think.
I initially put the long tube headers on and to be honest I didn't notice any improvement.
It goes like a rocketship now. Tune still needs a bit of work around idle but otherwise I am very happy.
I sold my refurbished and skimmed stock ally heads to a club member locally for $1000. He got a good buy I think.
I initially put the long tube headers on and to be honest I didn't notice any improvement.
It goes like a rocketship now. Tune still needs a bit of work around idle but otherwise I am very happy.
Last edited by Lemme; Jul 24, 2018 at 02:06 AM.
Thread Starter
Heel & Toe
Joined: Apr 2018
Posts: 16
Likes: 0
I was talking to a guy today who said a good budget option for my power desires would be some vortec iron heads. I also found an article online that said the vortec 170cc iron heads flow 228 cfm, whereas the later model stock l98 alloy heads flow 200 cfm. Could anyone back these statements up? Or would it just be a waste of time and money?
Safety Car
Joined: Sep 2001
Posts: 4,137
Likes: 531
From: Glenbeulah Wi
I was talking to a guy today who said a good budget option for my power desires would be some vortec iron heads. I also found an article online that said the vortec 170cc iron heads flow 228 cfm, whereas the later model stock l98 alloy heads flow 200 cfm. Could anyone back these statements up? Or would it just be a waste of time and money?
