How to make the most of the 20g?

[chrisgvr4]

Hey everyone,

This is my first post here at rmdsm. Some of you may know me from the track or CoDSM. Anyway I drive a 1991 GVR4 with a 20g and all the basic supporting mods.

This year a ran a 12.80 @ 109 at Bandimere with a weight of 3300 pounds.

Next year I want to run 11.99, without the nitrous if possible. In addition to the basic supporting mods for the 20g I have ordered a few things for next year.

Magnus SMIM plumbed with a NX direct port kit, HKS 272/272 cams, Ferrea 1mm over valves for my rebuilt head and crower springs and retainers.

Additionally I was having traction issues so I need to install the 4bolt LSD rear end and was considering a lighter wheel/stickier tire combination. I will also bump the rev limit up to 9500 rpms and have a TRE tranny to hopefully shift well wherever the best shift point is.

Am I missing any additional parts to take full advantage of the 20g? I don't want to get a bigger turbo until I reach the full potential of this turbo.

Thanks!

[v413nc3]

A water injection system couldn't hurt, also look into changing your spark delivery system. DSM's (and their cousins) are notoriously known for weak wasted spark systems. It sounds like you're well on your way though, btw, I was there for your runs that morning test and tune, good job :)

[TurboSpoolinIns]

There is a local here running a 20g on his 1g and I'd like to believe it is very close to maxing out. His setup is very basic but it includes everything you'd need to max a 20g out. If I can find you a list of his mods, I will post it because since you say you have all the supporting mods, I don't see why you wouldn't be maxing it out neither. He's gone 11.2 at 122 this last weekend with it and from when I've last talked to him is going to try to break a 10 on it. His car isnt that light I believe, probably over 2900 lbs still before driver

for sure I know its a TD06 20g with a Tdo5 exh. wheel
victory fmic w/ alum piping,
victory 02 w/ 40 mm tial
2g pistons
1g rods
arp headstuds
2.5" DP to 3" catback
aeromotive afpr
660s
255 walbro
greddy type s bov
hks 272s
1g semi-ported head
2g mas
s-afc

and everything else should be stock(suspension, intake mani, t/b, etc..)


here's his dyno chart on 30 psi and C16

[chrisgvr4]

Hey TurboSpoolinIns,

Thanks for some great information. If you can get his exact mods that would be awesome. I'll be assuming a few things so correct me if I'm wrong. First he is at sea level right?
So his pressure ratio is:
(30+14.7)/14.7=3.04
My PR at 25 psi up here is:
(25+12)/12=3.08

I'd like to turn the boost up more next season but I'm afraid at a PR of 3.5 the 20g won't be very efficient. Anyone have comments? Upgrading the turbo is not the answer, yet.

He is also probably lighter than me as well as more aerodynamic (especially since all my runs are *with* the roof rack on). Next season I will continue to strip weight until I get 3000 pounds with me in it. As for aerodynamics there isn't much I can do but pull the roof rack. ;)

As far as mods I have, I have everything on his list except:
2g pistons (I have 1g)
arp headstuds (going on soon)
2.5" DP (I have 3")
aeromotive afpr (going on soon)
greddy type s bov (1g with Dejon Mod)
hks 272s (going on for next season)

Also what about his rev-limit, suspension and tire setup? I'd be surprised if he isn't reving beyond 7500. I'm also having major traction issues. If I could put more power to the ground I could get 1.6 or 1.5 high 60 foots.

Keep the ideas coming. I don't want to use the nitrous @ the track until I make an 11 second pass if I can help it.

[hoffman]

I'm thinking wieght reduction would also help.

-replaced the heavy padded carpeting with non-padded carpet
-remove excess sound deadening material
-remove excess material from bumpers
-remove luxury items not used (cruise, a/c, power seating, spare tire)
-replace heavy glass with lexan
-replace heavy body parts with fiberglass/carbonfiber
-replace heavy wheels with lighter ones

no sense in getting retarded with it unless its going to be a purpose built racecar.

[TurboSpoolinIns]

Originally posted by chrisgvr4
Hey TurboSpoolinIns,

Thanks for some great information. If you can get his exact mods that would be awesome. I'll be assuming a few things so correct me if I'm wrong. First he is at sea level right?
So his pressure ratio is:
(30+14.7)/14.7=3.04
My PR at 25 psi up here is:
(25+12)/12=3.08

I'd like to turn the boost up more next season but I'm afraid at a PR of 3.5 the 20g won't be very efficient. Anyone have comments? Upgrading the turbo is not the answer, yet.

He is also probably lighter than me as well as more aerodynamic (especially since all my runs are *with* the roof rack on). Next season I will continue to strip weight until I get 3000 pounds with me in it. As for aerodynamics there isn't much I can do but pull the roof rack. ;)

As far as mods I have, I have everything on his list except:
2g pistons (I have 1g)
arp headstuds (going on soon)
2.5" DP (I have 3")
aeromotive afpr (going on soon)
greddy type s bov (1g with Dejon Mod)
hks 272s (going on for next season)

Also what about his rev-limit, suspension and tire setup? I'd be surprised if he isn't reving beyond 7500. I'm also having major traction issues. If I could put more power to the ground I could get 1.6 or 1.5 high 60 foots.

Keep the ideas coming. I don't want to use the nitrous @ the track until I make an 11 second pass if I can help it.

I believe that is it for his setup. He is on stock suspension, and as you can see from his latest dyno chart, he is only revving to 7500 if not less. He pulled a 1.74 60' I believe on the 11.2 run. I know his setup is very basic. He has transferred this exact setup on 3 different cars, this one being the 3rd car. It has made very similar power each time except when going from the last setup to this last setup. He went from 1g pistons to 2g pistons and upped the boost 2 psi. Also we are closer to sea level than you guys are but I still think we are up a couple hundred if not a thousand feet.

[chrisgvr4]

Great info TurboSpoolIns.

BTW I can't see the dyno sheet either at home or here at work. Link error? I'm curious to see his power fall off with a stock manifold and cams. I think my magnus manifold will help me make more power up top and shift later to keep the turbo spooled during the shift. Also my runs have been on 110 leaded. How does C16 compare? This year has been my first experiment with race gas and I haven't strayed from trusty 110.

I'm waiting on parts now but this winter I should get everything installed that he has except 2g pistons. I"ll experiment with upping the boost as well. Anyone else have comments on running a 20g at 30psi up here? Will it even hold that to stock redline? I obviously don't want to test it out w/o race gas and until the ARPs are on.

Lower elevation makes a very big deal since Bandimere is about 5800 ft. My 14b felt *so* much stronger at sea level (St. Louis, MO) and I'd expect the 20g to feel similarly because I'm getting close to maxing it out. If I wasn't maxing it out then I wouldn't expect as much difference. Hopefully I'll have enough fuel supply to make a few serious passes in STL next time I visit the family.

[TurboSpoolinIns]

Originally posted by chrisgvr4
Great info TurboSpoolIns.

BTW I can't see the dyno sheet either at home or here at work. Link error? I'm curious to see his power fall off with a stock manifold and cams. I think my magnus manifold will help me make more power up top and shift later to keep the turbo spooled during the shift. Also my runs have been on 110 leaded. How does C16 compare? This year has been my first experiment with race gas and I haven't strayed from trusty 110.

I'm waiting on parts now but this winter I should get everything installed that he has except 2g pistons. I"ll experiment with upping the boost as well. Anyone else have comments on running a 20g at 30psi up here? Will it even hold that to stock redline? I obviously don't want to test it out w/o race gas and until the ARPs are on.

Lower elevation makes a very big deal since Bandimere is about 5800 ft. My 14b felt *so* much stronger at sea level (St. Louis, MO) and I'd expect the 20g to feel similarly because I'm getting close to maxing it out. If I wasn't maxing it out then I wouldn't expect as much difference. Hopefully I'll have enough fuel supply to make a few serious passes in STL next time I visit the family.

Here's the link to his dynochart.

http://www.dsmstyle.com/2g/dynowcar.jpg

He does have the stock intake manifold, but has HK$ 272's for cams. I don't believe it holds 30 psi to redline, but then again, I don't remember if that was a boost leak issue or whatnot for him or if it was that the turbo couldn't do it. As for his 1g piston dynoing on C16, I know he made around 391 whp on about 28 psi. On 30 psi and the 8.5 compression, he made the 426 whp. When both dyno charts were compared, there was a noticable difference in spoolup. The 2g pistons/compression did help spoolup a little bit. I'd hope your magnus intake will not let power drop off as much up top because I've yet to put my magnus on :cool: . The only real way you're going to take advantage of that magnus is to obviously raise your revlimiter higher ( to 8 or 8500 ) if you are still making power on the 20g. Depending on what kind of 110 you are using, I wouldnt see that much a difference in C16 and other 110 race gases. The other 110s will probably just have more lead and I'd say it's fine if you don't want to spend $9+/gal.

[chrisgvr4]

Yep a raised rev-limiter is going to be key to take advantage of the cams and intake combo. My head will be built to take it and I hope to get on a dyno to learn where power falls off sharply. I just need to rev high enough so that the turbo stays spooled and the power doesn't fall off too much. Raising the actual rev limit will be easy next season, I can have chips burned to do whatever I want I believe. And I hope my TRE tranny will love me and shift at 8000-9500 etc. We'll see.

Oh ya...the dyno link still doesn't work for me. Can anyone else see it?

[TurboSpoolinIns]

Originally posted by chrisgvr4
Yep a raised rev-limiter is going to be key to take advantage of the cams and intake combo. My head will be built to take it and I hope to get on a dyno to learn where power falls off sharply. I just need to rev high enough so that the turbo stays spooled and the power doesn't fall off too much. Raising the actual rev limit will be easy next season, I can have chips burned to do whatever I want I believe. And I hope my TRE tranny will love me and shift at 8000-9500 etc. We'll see.

Oh ya...the dyno link still doesn't work for me. Can anyone else see it?

Now the link doesnt work because the host server was changed. I will ask him to see if he has it posted somewhere else.