Low numbers with VMP TVS 2.3

[ModMike1572]

Trying to get some feedback here..

My original setup was the standard 3.00 upper pulley only (17lbs). Supporting mods are BAP, 80lb injectors, Mass Air, NGK Plugs, JLT Cold Air. Exhaust is stock manifolds, upr o/r x, and magnaflow catback.

The car was putting down in the 560-570 range but the belt was slipping. Along with getting the new belt, I decided to drop down to the 2.8 pulley and throw some 100 octane to get deeper into the 600's where I want to be.

Car put down 585rwhp with this setup. Boost was peeking at 19lbs but was dropping off. Is the throttle body where the restriction is? Any other ideas/opinions? Also keep in mind it was hot and humid as hell down here in south FL yesterday so I'm sure that has an effect as well.

Matt, my tuner will be posting the graph today also.

 

[fr03cobra]

do you have the gt500 t/b? you might need to get a return style fuel system and get rid of the bap. you still have stock pumps?

 

[ModMike1572]

do you have the gt500 t/b? you might need to get a return style fuel system and get rid of the bap. you still have stock pumps?

Stock pumps/bap with stock throttle body.

 

[stagedz]

You don't need the GT500 throttle body unless your planning on running 23+psi which is probably not a great idea on the 2.3...just get an accufab and save yourself the extra money. The throttle body is most likely your restriction...though at 17psi 570 is pretty good. I was using a stock ported throttle body on my whipple 2.3 and had boost drop off issues as well...now it seems to hold steady with the single blade billetflow...also I picked up about 15rwhp over the entire rpm range.

 

[stagedz]

also I wouldn't try pushing past 19psi with your current fuel setup. You don't have to go return but you might want to at least consider upgrading your fuel pumps.....if it was my car I would just keep the 17psi tune and upgrade the throttle body to a single blade.

 

[03cobraracer]

yeah definitely a single blade should help you out. and then maybe at least a set if bigger pumps, GT pumps or something. im running 60s, gt pumps in kurgan hat, and BAP and im fine at 617hp at 21lbs with torco.

 

[Iamchris]

The throttle body confuses me. If you look around, there are some folks running stock TB with Whipple 2.3 and making mid 600's. I think they are on E-85... but it shouldn't matter... that is fuel, we are talking air. So if the blower is capable of 650 on a stock TB, I am surprised to find it being the blame.
In my little pea brain, I can see it mattering... but not being the bottle neck... not when I see evidence that folks are making more power with stock TB.

 

[03cobra#694]

On my phone, so might have missed it. Who tuned it ?

 

[TVS VERT]

Unless that is on a super tight mustang dyno....something is wrong....and no you don't need a gt500 throttle body...spend $$ else where

 

[ModMike1572]

On my phone, so might have missed it. Who tuned it ?

Matt @ Kesatie Motorsports. He is great btw. He is guessing the stock throttle body is where the restriction is. Also, you're right up the road from me, you know how HOT and HUMID it was yesterday, lol. Another guy was down 20-30hp on the dyno because of the temps.

 

[stagedz]

The throttle body confuses me. If you look around, there are some folks running stock TB with Whipple 2.3 and making mid 600's. I think they are on E-85... but it shouldn't matter... that is fuel, we are talking air. So if the blower is capable of 650 on a stock TB, I am surprised to find it being the blame.
In my little pea brain, I can see it mattering... but not being the bottle neck... not when I see evidence that folks are making more power with stock TB.

From my experience the boost starts dropping off too much with the stock throttle body thus lowering the peak HP numbers...however it could also be belt slip though you can usually see that on the dyno graph. I don't really think 580 at 17psi is low for a dynojet and a 2.3 with a stock throttle body...I tend to think a lot of people over 600 at that psi are on a very "friendly" dyno...I imagine if you lined the 580 17psi up at the track and the 600 17psi car at the track the times(edit) and MPH (edit) would be almost identical if all other factors were the same.

 

[blk00gtvert]

i need to post up the chart yet...

he still has some duty cylce left on the pumps. definitly not an issue there. it was getting belt slip but we installed the aux idler so no more slip. boost peaks at 19 psi and just very slowly drops to 17 by the end of the run. so basicly its making the same boost at peak power with the 2.8 as it did with the 3.0. the extra power came from the torco which allowed 21 degrees vs 18.

and as said was VERY humid out yesturday.

i did speak with justin from vmp that said 570 on a 3.0 pulley on pump 93 waas exactly where it should be... i just found it strange that dropping to a 2.8 did not result in any more peak boost. hence why i am suspecting the tb might be restricting airflow?

 

[Bdubbs]

Mod's in my sig, I have a 3.0 upper with gt500 tb and my car made 576/528 with some belt slip up top. From what I gathered my numbers too are where they should be for the pulley combo I'm running on 92 pump gas. Even though I was hoping for a little more.

EDIT: I agree with Stagedz with the dyno. I've seen a lot of members on here make well north of 600rwhp with 2.8 or even over 600rwhp with a 3.00 upper. This proves how each dyno is different, and it seems that shops can make a dyno read whatever they want it to.

Per boost and my setup, my shop told me before I got my car on the rollers I wouldn't make 600rwhp and this is on a dyno jet.

 

[03cobra#694]

Matt @ Kesatie Motorsports. He is great btw. He is guessing the stock throttle body is where the restriction is. Also, you're right up the road from me, you know how HOT and HUMID it was yesterday, lol. Another guy was down 20-30hp on the dyno because of the temps.

Yes I am, and have heard good things about them. Yup, not far from you at all, and has been pretty warm and humid.

 

[whitedevil95]

Plus most. Guys making 600+ have built fuel systems, E85, and run upper and lower pullies and 21+ psi

 

[ModMike1572]

Per boost and my setup, my shop told me before I got my car on the rollers I wouldn't make 600rwhp and this is on a dyno jet.

Ya, we put down around the same with the 3.0 pulley at 17lbs (570). But with the 2.8 and 100 octane we should have been north of 600. Trying to figure out why boost was dropping from 19 to 17. Stock throttle body seems like the culprit.

 

[xxjaymanzxx]

Change the throttle body out for a bigger one and see how it does. Seems like that's the normal numbers to me

 

[03cobra#694]

Off topic, but I'd love to see the car mike

 

[ModMike1572]

Off topic, but I'd love to see the car mike

shoot me a PM buddy. Would love to get up sometime.

 

[Bdubbs]

Ya, we put down around the same with the 3.0 pulley at 17lbs (570). But with the 2.8 and 100 octane we should have been north of 600. Trying to figure out why boost was dropping from 19 to 17. Stock throttle body seems like the culprit.

Yeah I hear you there. Assuming you guys gave the car plenty of cool down time? Are you going with a different plenum/tb?