Your help with modification ideas please.
Thread Starter
Instructor
Joined: Apr 2002
Posts: 223
Likes: 0
From: Spokane Wa
Your help with modification ideas please.
I have a 1990 6spd. I like to auto cross and still drive it on the street. I dont want to go to crasy. I have done that before. I am not sure of my gear ratio. I do know that when many people are using 1st at an autocross. I have to use second because I am pushing 5-5500 rpm's in first and so on up the scale.
The car pulls very hard in the first four gears. To the best of my knowledge it is mainly stock.
I have change the timing + 4 deg, air foil, duel air filters, Now cold air inducted. K&N filters, 8.8 plug wires, free flow exhaust with flow masters.
I am thinking that I would like to go with 1.6 rockers, Port/polish the heads and intake. 2.0 Intake and 1.56 Exhaust valves. Comp cam has one that shows 208-214 dur and 452-468 lift. with the 1.6 I would be in around 490-500 range. This would keep me in the high-low end torque and fast revving plan. With just maybe the 5-600 more rpms than I have now. I am considering short headers since my car is lowered and I already can't go over a peanut. I would then need to focus on the distributer to bring that up to the new requirements.
Anyone been this route any ideas. thanks
:cheers:
The car pulls very hard in the first four gears. To the best of my knowledge it is mainly stock.
I have change the timing + 4 deg, air foil, duel air filters, Now cold air inducted. K&N filters, 8.8 plug wires, free flow exhaust with flow masters.
I am thinking that I would like to go with 1.6 rockers, Port/polish the heads and intake. 2.0 Intake and 1.56 Exhaust valves. Comp cam has one that shows 208-214 dur and 452-468 lift. with the 1.6 I would be in around 490-500 range. This would keep me in the high-low end torque and fast revving plan. With just maybe the 5-600 more rpms than I have now. I am considering short headers since my car is lowered and I already can't go over a peanut. I would then need to focus on the distributer to bring that up to the new requirements.
Anyone been this route any ideas. thanks
:cheers:
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Your help with modification ideas please. (fnseeker)
You have a pretty good recipe there.
25-30 cam (like ZZ-9 or Super L98)
25hp ported & worked #113 heads
Instead of shorty headers, do a hi-flow front Y and port your stock headers, along with a hi-flow cat. It might be worth 15hp or so.
Either go with the BM intake base and LT runners (15hp) or try the siamese base with stock runners (20hp at 5,400rpm). A 52mm TB and ported plenum would also be a good idea. You will definitely need some kind of intake mod to supply enough air for the heads and cam.
A HyperTech coil/cap/rotor and cut-back AC Delco plugs gapped to .045" will assure good top end firing and bring another 10hp.
Though an AFPR may be enough for tuning you may also need a custom chip with the cam, depending on how your vacuum holds.
I think your stock injectors may just keep up with those needs (350-370hp at the crank).
When you do the heads & cam chose springs to match the cam with 1.6 RRs, toss the oil sheders and go up to Ti retainers with 10deg locks. A set of 7/16" studs wouldn't be a bad idea either.
That combo should push your shift points over 6k RPM and provide a nice boost in HP and torque.
I'm sending you some data on results of similar mods.
25-30 cam (like ZZ-9 or Super L98)
25hp ported & worked #113 heads
Instead of shorty headers, do a hi-flow front Y and port your stock headers, along with a hi-flow cat. It might be worth 15hp or so.
Either go with the BM intake base and LT runners (15hp) or try the siamese base with stock runners (20hp at 5,400rpm). A 52mm TB and ported plenum would also be a good idea. You will definitely need some kind of intake mod to supply enough air for the heads and cam.
A HyperTech coil/cap/rotor and cut-back AC Delco plugs gapped to .045" will assure good top end firing and bring another 10hp.
Though an AFPR may be enough for tuning you may also need a custom chip with the cam, depending on how your vacuum holds.
I think your stock injectors may just keep up with those needs (350-370hp at the crank).
When you do the heads & cam chose springs to match the cam with 1.6 RRs, toss the oil sheders and go up to Ti retainers with 10deg locks. A set of 7/16" studs wouldn't be a bad idea either.
That combo should push your shift points over 6k RPM and provide a nice boost in HP and torque.
I'm sending you some data on results of similar mods.
Melting Slicks
Joined: Apr 2002
Posts: 3,019
Likes: 0
From: down that one road next to that big tree
Re: Your help with modification ideas please. (65Z01)
the only thing i'm thinking is the 208/214 isn't going to be a lot different than stock, maybe something like the accel 211 cam or the comp 218/224 grind if you want more top end. the zz9 is also a good contender. since you want as much torque as possible and aren't concerned with going over 6000, the comp or accel would probably be my choices, here's a link to a dyno chart of the xr270hr cam i was suggesting from comp, it's a tight grind & will really wake up early. http://www.compcams.com/information/...0HR-10_001.asp
Thread Starter
Instructor
Joined: Apr 2002
Posts: 223
Likes: 0
From: Spokane Wa
Re: Your help with modification ideas please. (65Z01)
I am a concerned on how much lift you can safely and effeicently place on the factory heads. With my already having the 1.6 rr I would like to stay in the 500 lift range. The duration I am a little more open on. But i really don't see a need for running over 6000 rpms for what I will be using this motor for. I am more concerned that it develops hp/torque quickly out of the hole and has at least some rpms to play with.
I agree the heads and intake need to flow more. Does the factory intake have enough removable material to make this happen. I have debated on siemesing the stock runners like I have seen here on c/f. Does this take away from the low end more than I would like. Giving that I will not be going up in Cubic Inches. :confused:
I agree the heads and intake need to flow more. Does the factory intake have enough removable material to make this happen. I have debated on siemesing the stock runners like I have seen here on c/f. Does this take away from the low end more than I would like. Giving that I will not be going up in Cubic Inches. :confused:
