Looking for more top end...

[DavisGST]

Hi all,

I am looking to get some more top end out of my car. Currently running a Big16G with the usual supporting mods(550's, AFC, supra smic, 190 pump, turbo back, etc). I run 16 psi on 91 octane.

The car has great response above 3400 rpm and pull hard to redline but I am looking for a bit more pull up top.

I was thinking about swapping out to a 1G throttle body, aftermarket intake manifold, ported 1G heads and HKS cams.

Of course my other choice is larger turbo but I recently drove another DSM with a 20g(TDH06) plus all the supporting mods, and while the car had the top end I was looking for the turbo response was a bit lacking. The car had major lag at anything below 4200 rpm. After that the car really didn't wake up until 5K but then it was real nice.

Any opinons would be a great help.

Thanks for your time and effort.

-Darren.

 

[Airpoppoff]

I would really look into getting a nice set of cams for your setup, It helped in my top end, ALOT

matt

 

[prostreetdsmx1]

HKS 264/272, enough said! we put them in out shop car and got a lot more power up to. all of our customers LOVE THEM!

 

[pkat337]

Well if you increase your flow through your heads through porting and cams then your 16g turbo may become a restriction in the exhaust. If you just upgraded to a 20g then you will get crazy lag as you have already discovered. I would say the best thing would be to do both. But if you had to choose between the two then it is really a matter of compromise. The most top end and most lag with just the turbo or the most top end the 16g can support and maybe actually decrease the lag a bit. For street performance go with the head work and cams. For the strip 20g all the way.

 

[DavisGST]

Thanks for the input.

Looks like I will go with some ported 1G heads and cams.

Darren.

 

[NOSLO2PT0]

20G has crazy lag up to 4200rpm? You guys must not know how to tune. I haven't even tried to tune my car for quickest spoolup and I can get 25psi by 3900rpm on my Green. That's with an FRH Manifold and 272's.

 

[jdmawd]

Originally posted by DavisGST
Hi all,


I was thinking about swapping out to a 1G throttle body, aftermarket intake manifold, ported 1G heads and HKS cams.

-Darren.

thats the ticket

 

[Airpoppoff]

Originally posted by NOSLO2PT0
20G has crazy lag up to 4200rpm?

no way????

 

[13secGST]

top end? Cams, cams, cams, cams, cams...

 

[DavisGST]

NOSLO2PT0:

The car I drove is my brothers 97 GST has a 20G. Usual supporting mods(FMIC, 660s, 255lph,AFC, turbo back, etc).

All mods where installed at Road Race Engineering in Santa Fe Springs, CA. Installation was done by Tony and the tuning was done by Mike and Roy. So I am pretty sure the car is working just fine

I know this first hand since they installed by Big 16G at the same time they were working on his car.

I am just stating the impressions of the car after I drove it. I am sure that RRE knows a thing or two about tuning.

You are right though I don't know anything about tuning. Thankfully RRE handles that for me.

 

[Generation X]

Originally posted by DavisGST
Hi all,

I am looking to get some more top end out of my car. Currently running a Big16G with the usual supporting mods(550's, AFC, supra smic, 190 pump, turbo back, etc). I run 16 psi on 91 octane.

The car has great response above 3400 rpm and pull hard to redline but I am looking for a bit more pull up top.

I was thinking about swapping out to a 1G throttle body, aftermarket intake manifold, ported 1G heads and HKS cams.

Of course my other choice is larger turbo but I recently drove another DSM with a 20g(TDH06) plus all the supporting mods, and while the car had the top end I was looking for the turbo response was a bit lacking. The car had major lag at anything below 4200 rpm. After that the car really didn't wake up until 5K but then it was real nice.

Any opinons would be a great help.

Thanks for your time and effort.

-Darren.

I'm in the same boat as you except I have a ported FP Big28 with supporting mods. I have been contemplating on either the new FP 2544 or the FP green. I have also thought about just adding some HKS 264/272 cams to compliment my FP Big28, I don't know though. What I do know is, I want to be able to trap around the 114-115 range in the 1/4 but still have a decent quick spool. I don't think I will be able to trap in the 114- 115 range with the Big28, even with cams.

 

[DCJ98GST]

Originally posted by Generation X
....I have also thought about just adding some HKS 264/272 cams to compliment my FP Big28...

Why is it that everybody seems to go with the 264/272 set up instead of the 264/264 set up?

I have seen tests where there is not much difference between the two on top end, but you get alot more lag, and slower response with the 264/272 mix?? Especially with smaller turbos.

Wouldn't the mix of cam overlap hurt response?

 

[Generation X]

Originally posted by DCJ98GST
Why is it that everybody seems to go with the 264/272 set up instead of the 264/264 set up?

I have seen tests where there is not much difference between the two on top end, but you get alot more lag, and slower response with the 264/272 mix?? Especially with smaller turbos.

Wouldn't the mix of cam overlap hurt response?

Yeah I agree. If I do decide to keep my FP Big28 I will indeed go with the 264/264 set up. The only reason I was thinking about the 264/272 combo, is if I decide to go with a larger turbo on down the road. I think the 264/272 would then show more power potential. I'm just merely going by what I have personally searched and read. I myself have seen a similar cam comparison where they compared the WEBS, HKS, and JUN cams, but they didn't go any bigger than a 16g turbo when they did the testing, and or comparison. I think an FP Green would make a little more power with the 264/272 combo rather than the 264/264 combo, and even more with the 272/272 combo. But yes, I would think there would be a slower response but it would make it up on the top end.

 

[prostreetdsmx1]

272 is defin. for bigger turbo's. 264 is way to small for 50trim and above. and i can personally tell you that our cars have done more topend power with a 272 exhaust that a 264......